TECHNICAL FIELD

The present invention regards mononuclear Au-based and Cu-based coordination compounds, pharmaceutical formulations thereof, the related synthesis and encapsulation method in macromolecules, supramolecular aggregates or nanostructures, as well as their use in the diagnosis and/or the treatment of neoplasms. Advantageously, such coordination compounds and/or their formulations can be glycoconjugated with carbohydrates which act as cancer- targeting moieties thus increasing the therapeutic selectivity. BACKGROUND ART

Cisplatin is a milestone among the anticancer compounds and, since its introduction in pharmacopoeia in 1978, has shown to be one of the most effective drugs, particularly in the treatment of testicular, ovarian, lungs, bladder and uterine cervix cancer, mesothelioma and head and neck carcinoma. Despite its therapeutic efficacy, the clinical use of cisplatin is characterized by severe side effects. The most serious one is the high toxicity, especially to kidneys, to auditory apparatus and to bone marrow. In addition, cisplatin demonstrates intrinsic or acquired resistance to certain tumors. Finally, it is characterized by a very limited intrinsic selectivity, so that only a small percentage (around 2 - 5% in moles) of cisplatin reaches the tumor cell DNA, which is currently recognized as its most important target. Further limitations to the clinical use of cisplatin are the poor solubility and the high reactivity of the platinum(ll) center which limit the bioavailability and, therefore, the mode of administration.

The intense research activity carried out in the recent decades has attempted to moderate these effects and limitations but has only partially achieved the desired effects. In fact, the numerous cisplatin-like compounds, such as carboplatin and oxalilplatin, still have a lower anti- tumor activity or a poor toxicological profile. The main reason for this failure is due to the fact that this metal has a high affinity for sulfur-containing residues of biomolecules.

As mentioned above, the oncological research in recent years has considered alternative approaches that will be described briefly here.

A first strategy aims to synthesize new coordination compounds with metal centers other than platinum that can maintain the antitumor activity but, at the same time, are characterized by a better toxicological profile. For example, in a first patent Fregona et al., were able to synthesize a class of Au(lll) dithiocarbamato complexes, described in ITMI20030600 which proved intrinsically less toxic than the Pt(ll) counterparts. Moreover, in a second document, WO2010105691 A1 , Fregona et al. have claimed a new class of Au(lll) dithiocarbamato compounds functionalized with a peptide moiety designed to be internalized by tumor cells by PEPT transporters. However, the syntheses therein proposed do not permit to obtain the compounds in pure form, but as a mixture of two different complexes having the same empirical formula. This result was not evident from the elemental analysis. This aspect represents a serious limitation, as in the oncology field, syntheses that lead to pure compounds or to mixtures of easily purified molecules are needed in order to favor both administration to humans and the industrial-scale production. In addition, for some types of cancer, PEPT transporters do not represent the optimal target to favor selectivity as they are not adequately overexpressed in tissues.

Another example of Au(lll) dithiocarbamates (DTC) with metal-ligand stoichiometry 1 : 1 is represented by the complexes reported by Shi Yanan and co-workers (Inorg Chem Comm, 2013) containing piperidine, morpholine and piperazine DTC derivatives. Other three examples of dichloro and dibromo Au(lll) dithiocarbamato compounds with metal-DTC ligand ratio 1 :1 are listed below. L. Ronconi et al. (Inorg Chem., 2005) described the synthesis, the characterization and in vitro activity of Au(lll) complexes containing ethylsarcosine-(A/-methylglycine ethyl ester) and dimethylamine-based DTC ligands.

In a subsequent work, C. Nardon and co-workers (Chem Open, 2015) reported novel Au(lll) compounds containing pyrrolidine-DTC with antitumor activity. M. Negom Kouodom et al. have reported the synthesis and antitumor activity of Au(lll) dithiocarbamato derivatives containing oligopeptides (tri-, tetra- and penta-peptido ligands) (J. Inorg. Biochem, 2012).

An example of Au(lll) complexes with different metal-DTC ligand stoichiometry (1 :1 , 1 :2) is represented by the compounds reported by M. Altaf et al. (Altaf, RSC Advances, 2015). In this work, dimethylamine, diethylamine and dibenzylamine Au(lll) dithiocarbamato molecules are studied and their in vitro antitumor activity is evaluated.

In addition to the aforementioned examples of Au(ll l) complexes, some papers reported in the literature describe mononuclear Cu(ll) dithiocarbamato complexes. In particular, L. Giovagnini et al. (Inorg. Chem. 2008) reported the synthesis, the characterization and the in vitro anti-tumor activity of Cu(ll) compounds with dimethylamine, pyrrolidine and sarcosine (methyl, ethyl and tertbutyl esters) DTC-based ligands.

In other works, Cu(ll) dithiocarbamato compounds have been synthesized for different purposes. For example, A. Diaz and colleagues (J. Inorg Biochem, 2003) synthesized homoleptic complexes containing morpholine and proline ligands in order to study their interaction with the NO molecule. R. Cao et al. (Inorg Chem, 201 1 ) reported a series of heteroleptic derivatives containing morpholine, 4-hydroxymethylpiperidine, piperazine, proline and 4-methanethiopiperidine-based DTC ligands, coupling them with gold nanoparticles, thus obtaining a system with the ability to mimic the superoxidodismutase enzyme. Shahab Nami et al. (J. Photochem Photobiol. B, 2016) describe macrocyclic complexes with pyrrolic DTC ligands of the type L2X2, endowed with antibacterial activity. Moreover, A. Fragoso and colleagues (J. Supramolec. Chemistry, 2001 ) reported Cu(ll) dithiocarbamato complexes with piperidine, 2- hydroxymethyl and 2-hydroxyethyl piperidine-based ligand, and with a-C2, -C2 and -C6 cyclodextrins functionalized with a DTC group. From a purely synthetic point of view, B. Macias et al. (Polihedron, 2010) obtained a "double complex salt" complex containing a homoleptic Cu(ll) complex with proline-based DTC ligands as anion.

Along with the development of new coordination compounds, a second and promising strategy in the oncological research is associated with the exploitation of the so-called Warburg effect. In this regard, most cancer cells trigger an accelerated metabolism sustained by an high carbohydrate consumption, if compared to healthy cells. In particular, tumor cells produce energy mainly through glycolysis, followed by the reduction of pyruvate to lactic acid in the cytoplasmic matrix, rather than oxidation of pyruvate within the mitochondria, which is the favorite ATP-producing mechanism in almost all the normal cells. The enclosed Figure 1 clearly highlights that the expression levels of the GLUT1 transporter generally increase during the neoplasia development, as well as with the degree of malignancy of the tumor itself.

Nowadays, this phenomenon is exploited in imaging-based diagnostic techniques and in the oncological patient follow-up via the administration of the tracer FDG (2-[ ¹⁸ F] fluoro-2-deoxy-D- glucose). Accordingly, glucose and other carbohydrates are potentially useful biomolecules to selectively target antitumor agents. According to this approach, a variety of glyco-conjugates made up of known cytotoxins or chemotherapeutics linked to glucose (or other carbohydrates) have been synthesized to increase their selectivity to and absorption by the tumor cells. For example, the glyco-conjugate glufosfamide is currently in clinical trials for the treatment of ovarian and pancreatic cancer, glioblastoma multiforme and non-small cell lung carcinoma. Other examples of metal and non-metal glyco-conjugates derivatives are cited in various works published in recent years, including that of Emilia C. Calvaresi and Paul J. Hergenrother "Glucose conjugation for the specific targeting and treatment of cance , the paper of S. Tabassum and coworkers "Exploration of glycosylated-organotin(IV) complexes as anticancer drug candidates", and the work of P. M. Abeysinghe and M. M. Harding "Antitumour bis(cyclopentadienyl) metal complexes: titanocene and molybdocene dichloride and derivatives".

Concerning the patent literature, for example, Lippard et al. attempted to overcome the above- mentioned limits of platinum-based drugs through the conjugation of one or more metal- coordinated ligands with different cancer-targeting moieties, including carbohydrates. However, these documents {e.g., the patent US/ 2014/034313), claim but do not describe synthetic procedures useful for an expert in order to conjugate a coordination compounds to carbohydrates, to be used just as cancer-targeting moieties.

To sum up, according to the best knowledge of the present inventors, only a limited number of coordination compounds coniugated to sugars, their synthetic processes, optimized for a specific metal, are known up to date.

Lastly, a further strategy adopted to mitigate the side effects (toxicity) and the limitations (low solubility and bioavailability) of cisplatin, as well as of other drugs used in oncology, is the recourse to encapsulation techniques in supramolecular systems, such as liposomes. However, if these techniques are already mature in the oncological field for organic compounds, the encapsulation of coordination compounds is still in the early stages due to inherent difficulties when combining highly- reactive metal-based compounds with biocompatible polymers. For these reasons, the encapsulation of coordination compounds is a still poorly explored research field in literature, except for some studies related to platinum derivatives. Among these, at present the formulation of cisplatin in liposomes composed of cholesterol and phosphatidylcholine, known with the LipoPlatin ^® is in phase III clinical trials. In addition, cisplatin modified to bond by a linker (polyglutamic acid) the PEG (Nanoplatin ^® , NC -6004) has received the authorization to start the clinical phase III of test on pancreatic cancer in combination with gemcitabine. Among the formulations based on cisplatin substitutes, oxalilplatin encapsulated in liposomes (known under the trade term of Lipoxal ^® ) is currently in an advanced stage of development, while the same oxalilplatin, encapsulated in transferrin-conjugated liposomes (MBP-426), has completed the Phase I. A modified oxalilplatin (NC-4016) wherein a PEG is linked to the platinum(ll) metal center via a polyglutamic acid linker is about to start the phase I.

TECHNICAL PROBLEM

The intense research activity conducted over the last few decades has attempted to mitigate the side effects (toxicity) and the limitations (low solubility and bioavailability) of cisplatin, but the strategies adopted so far have only partially achieved the desired results.

Due to the peculiar reactivity preferably against neoplastic cells, drugs based on coordination compounds still represent one of the most promising anti-cancer option, but there is a need to make available a large number of new compounds with metal center other than platinum, which may replace cisplatin in the future, considering that most candidate compounds do not pass the advanced preclinical or clinical tests and therefore do not become drugs.

There is also a need for other coordination compounds with metals other than platinum and conjugated with cancer-targeting moieties, represented by carbohydrates, potentially useful in oncology and characterized by high selectivity (limited or negligible "off-target activity") and effectiveness towards different types of tumors and ultimately low or negligible toxicity. Lastly, it is necessary to have coordination compounds with metals other than platinum encapsulated in supramolecular aggregates, such as micelles, liposomes or cyclodextrins, which are conjugated or not to cancer-targeting moieties represented by carbohydrates.

DISCLOSURE OF INVENTION OBJECT/SCOPE OF THE INVENTION

Through the present invention, the present inventors intend to overcome the existing limits in the state-of-the-art related to coordination compounds useful as antitumor agents.

Accordingly, it is a first and main object of the present invention to design and synthesize Au- based and Cu-based mononuclear coordination compounds to be used as antitumor agents. Furthermore, a second object of the present invention is to identify mononuclear Au-based and Cu-based coordination compounds with carbohydrate-functionalized ligands which act as selective cancer-targeting moieties. Particularly, the present invention intends to disclose the advantageous use of carbohydrates as selective cancer-targeting moieties. In addition, carbohydrates could provide the additional advantage of increasing the solubility of the final compound in aqueous media.

Still, a third important object of the present invention is to identify coordination compounds endowed with low or negligible toxicity with respect to other metal-based compounds, such as cisplatin and subsequent compounds, a fourth object of the present invention is to identify coordination compounds characterized by high solubility in aqueous media, high stability and bioavailability, inherent or achieved by encapsulation in macromolecules, nanostructures or supramolecular aggregates, such as micelles, liposomes, proteins or cyclodextrins.

In particular, such structures may or not be functionalized with carbohydrates on the outer surface.

Moreover, a fifth object of the present invention is to provide a stable pharmaceutical formulation including one or more of said coordination compounds, usable as an antitumor agent and preferably administrable intravenously or orally. Such formulations may optionally include additional anticancer drugs.

Within the above-mentioned main tasks, a further object of the present invention is to provide a method for synthesizing said mononuclear Au-based and Cu-based coordination compounds, bioconjugated or not with carbohydrates, as well as a method for encapsulating said compounds in macromolecules, supramolecular aggregates made up of biocompatible polymers, functionalized or not with carbohydrates.

In addition, a further object of the present invention, is to disclose the use of said coordination compounds as antitumor agents, particularly in the treatment of "orphan tumors", such as the "triple negative" breast cancer (TNBC), the castration-resistant prostate cancer (CRPC), head and neck cancer, the NSCLC, the melanoma, the mesothelioma, the lung, pancreas and liver carcinoma.

Last but not least, a final object of the present invention is to produce coordination compounds which, besides possessing the necessary chemical-biological properties, are stable and obtainable through a synthesis process both able to intrinsically yield high-purity compounds and being industrially applicable with known and cost-effective technologies compared to state- of-the-art solutions.

TECHNICAL SOLUTION

In view of the above disadvantages or drawbacks of the prior art, the present inventors have made a lot of studies related to the preparation of coordination compounds useful as anti-cancer agents. After long terms of practice the inventors found a new class of Au-based and Cu-based mononuclear coordination compounds, which are described by one of the following general formulae 1(a) or 1(b):

1(a) 1(b)

wherein M identifies the metal center of the coordination compound which can be Au(lll), Cu(ll) or Cu(lll). The mononuclear coordination compounds herein disclosed are neutral or ionic complexes whose charge is neutralized by at least one counter-ion G and have different coordination geometries, for example square-planar, tetrahedric or pyramidal.

Further features and advantages of the new coordination compounds and the corresponding synthesis and encapsulation methods thereof, as well as the use of said compounds, will become apparent to those skilled in the art via the detailed description of its four preferred embodiments, herein provided below by way of example but not limitation.

In a first preferred embodiment of the present invention, the coordination compounds of formula l(a) or l(b) are not bioconjugated with a cancer-targeting moiety and act as antitumor agents due to the inherent reactivity of the Au and Cu metal centers. Surprisingly, some of these compounds exhibit an unexpected solubility in physiological media in spite of the presence of hydrophobic groups in the structure.

In a second preferred embodiment, the coordination compounds of formula l(a) or l(b) are bioconjugated with a carbohydrate which acts as a selective cancer-targeting moiety, advantageously exploiting the so-called "Warburg effect". Surprisingly, the presence of the cancer-targeting moiety, in combination with the physico-chemical properties of the final compound {e.g. ionic nature), can result in a very high solubility in physiological media.

In the third preferred embodiment of the present invention, the coordination compounds of formula l(a) or l(b) are encapsulated in macromolecules, nanostructures or in supramolecular aggregates, such as liposomes or cyclodextrins, acting as carriers to carry out a passive- targeting mechanism mediated by the Enhanced Permeability and Retention (EPR) effect that characterizes tumor districts. Said compounds may be or not conjugated with carbohydrates. In a fourth preferred embodiment, the coordination compounds described in the formula l(a) or l(b) may be addressed to the tumor site by encapsulating such compounds in macromolecules, nanostructures or supramolecular aggregates, for example micelles, in turn functionalized with carbohydrates to achieve an active-targeting approach ("Warburg effect"), which accompanies and strengthens the passive-targeting mechanism of the previous embodiment. Even in this case, the encapsulated compounds can be or not conjugated with carbohydrates.

ADVANTAGEOUS EFFECTS OF INVENTION

The coordination compounds of structure 1(a) and/or 1(b) according to four preferred embodiments have a number of remarkable advantages which cannot be achieved by prior art compounds as it will be apparent to those skilled in the art.

First of all, the present invention discloses Au-based and Cu-based coordination compounds, glycoconjugated or not, which, according to experimental tests, possess remarkable anti-tumor properties. Furthermore, various synthesis processes of said coordination compounds have been disclosed, characterized by high yields: they allow the expert to choose the most advantageous scheme depending on the metal center and type of desired ligands, including those containing a cancer-targeting moiety represented by a specific carbohydrate. Said cancer targeting moiety and metal centers can in turn be chosen based on the molecular profile of the patient's neoplasm according to the paradigm of personalized medicine.

The Ru-based and Ga-based coordination compounds according to the present invention can be loaded into supramolecular aggregates or macromolecules, consisting of a wide range of biocompatible polymers so to obtain stable nanoformulations. In other words, said compounds do not react nor establish interactions with other loaded complexes, and with the polymeric carrier neither.

Advantageously, the coordination compounds and nanoformulations allow to realize a both active and passive cancer-targeting mechanism. These compounds are characterized by optimal LiPE values for a promising pharmaceutical development {"druglikeness").

Moreover, said nanoformulations not only make the hydrophobic active principles soluble in the aqueous media but also mask the active principles herein described, both hydrophobic and hydrophilic, from reactions/interactions with the cellular and molecular components of the blood. Additional objects and advantages of the invention will be set forth in part in the detailed description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

DESCRIPTION OF DRA WINGS

The present invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:

- Figure 1 shows the levels of expression of the glucose transporter (Glutl ) in different cell lines. In letter A), Northern analysis of the Glutl mRNA levels evaluated in healthy human prostate samples and in three different human prostate cancer cell lines with decreasing differentiation. LNCaP is a hormone-sensitive cancer cell line, whereas the

DU-145 and PC3 lines represent poorly-differentiated tumors (source: P. Effert et al., Anticancer Research 24: 3057-3064, 2004). In letter B), Western analysis of Glutl protein levels evaluated in samples derived from 4 different cell lines: cervix adenocarcinoma (HeLa), lymphoblast T (Jurkat), epidermoid skin cancer (A431 ), human embryonic kidney (HEK293) (from Abeam pic). Finally, in letter C), Western analysis of the Glutl protein levels evaluated (cell lysate 20 μς/Ιθηβ, anti-Glut-1 ab 2 g/mL, anti-β- actin ab 0.5 g/mL, secondary antibody 1 :1000) in samples derived from 3 different human cell lines: triple negative breast cancer (MDA-MB-231 ), pulmonary adenocarcinoma (A549), colon carcinoma (Caco2).

- Figure 2 illustrates the structure of some compounds solved by X-ray crystallography.

(A) [AuBr ₂ (PipeDTC)]; (B) [Cu(ProOMeDTC) ₂ ]; (C) [Cu(ProOfeuDTC) ₂ ], (D) [Au(PipeDTC) ₂ ][AuCI ₄ ]; (E) [Au(PipeDTC) ₂ ][AuBr ₂ ].

- Figure 3 collects the UV-Vis spectra recorded over time in saline solution for the coordination compound [Au(ProOtBuDTC) ₂ ]Br of general structure (V) encapsulated in dipalmitoylphosphatidylcholine (DPPC) liposomes (at 37 °C).

- Figure 4 shows the UV-Vis spectra of the coordination compound [Cu(ProOMeDTC) ₂ ] with general structure (IV). At the letter A) said compound is dissolved in aqueous medium consisting of pH 7.4 phosphate buffer/human serum (94.5-5% v/v), with a final

DMSO concentration of 0.5% i//i/ (the kinetics recorded at 37 °C for 72 hours). DMSO is an organic solvent used to pre-dissolve the compound. Conversely, at the letter B), the same coordination derivative is encapsulated in PF127 (5 mg/mL) micelles, dissolved in aqueous medium consisting of phosphate buffer pH 7.4 - human serum 95-5% v/v.

- Figure 5 shows the UV-Vis kinetic study recorded over 72 hours for the [Cu(PipeDTC) ₂ ] complex encapsulated in ΗΡ-β-CD in phosphate buffer/cell culture medium 9:1 v/v (at 37 °C).

Figure 6 represents TEM images of the formulations according to the third and fourth embodiments of the present invention in which micelles of PF127 (90%)/ glucose- conjugated PF127 (β anomer, O-glycoside) (10%) encapsulate the complex

[Cu(ProOMeDTC) ₂ ].

These figures illustrate and demonstrate various features and embodiments of the present invention, and of the manufacturing method thereof, but are not to be construed as limiting the invention. DETAILED DESCRIPTION OF THE INVENTION DEFINITIONS

For the purpose of understanding the specification and the appended claims, in the following description the chemical elements are defined by means of the respective symbols as reported in a common Periodic Table of Elements, such as that present in the "Handbook of Chemistry and Physics, 93rd ed ". In addition, unless otherwise indicated, the chemical symbol includes all isotopes and ions. Therefore, the chemical symbols C, F, Cu, Ga , Au and I include, as an example, their respective isotopes ¹¹ C, ¹⁸ F, ⁶⁴ Cu, ⁶³ Cu, ⁶⁵ Cu, ⁶⁸ Ga, ¹⁹⁸ Au, ¹³¹ 1, ¹²⁷ l, ¹²⁹ l. Moreover, the claimed and described structures are intended to include all possible isomers such as coordination isomers, structural isomers, and conformational isomers. In particular, wherever one or more chiral centers are present, the claimed and described structures are intended to include all possible optical isomers, such as enantiomers and/or diastereoisomers, their mixtures, either as racemic mixture or in various ratios. These chiral centers may be present in the coordination compound or already present in the involved chelating ligands, for instance in the molecular fragments comprising a carbohydrate T.

In the description and claims, the reference to classes of chemical compounds or functional groups, for example, an ester or an amide, has to be interpreted in the broadest meaning of the term in the chemical field, and, in particular it includes all possible types of substituents.

For the sake of brevity, the functional groups or solvents reported in the present invention may be indicated by acronyms or abbreviations widely used in the context of reference of the present invention (or defined in the aforementioned "Handbook?'). Finally, for the sake of clarity, in the general formulae the chelating dithiocarbamato ligand (also indicated with the acronym DTC) is represented through a stylized arch that connects two sulfur atoms, in accordance with the usual chemical notation.

In some preferred embodiments, the coordination compounds having formula l(a) and/or l(b) are bioconjugated to cancer-targeting moieties. This is a well-known term for an expert in the field, and it defines a molecular fragment of the compound (moiety), which has been ad hoc engineered for its recognition by cell-membrane proteins present in tumor cells. Within the scope of the present invention, said "cancer-targeting moiety" is a carbohydrate, and according to this, the terms "glycoconjugation" and "glycoconjugates" will be also used to indicate the "bio- conjugation" and the "bio-conjugates", respectively. The synthetic processes of the first and second embodiments involve amino functional groups for the preparation of the dithiocarbamato ligand. These groups may be ad hoc introduced in a specific stage of the process, or alternatively they can be generated by subsequent reactions during the previous steps. On the other hand, a suitable amine reagent can be purchased and used as such. Anyway, in the context of the present patent, these amino groups and amine reagents will be defined "precursor amine(s)" for brevity.

Some embodiments of the present invention involve the term "pharmaceutical formulations" to define preparations made up of a therapeutically-effective amount of the coordination compounds of Formula I (a) and/or l(b ) together with "pharmaceutically acceptable" additives and/or diluents and/or excipients. These additives, diluents, and excipients are intended to be compounds that, in contact with animal or human tissues, in light of their composition, dosage and administration route or anything else, do not cause any toxicity, irritation, allergy, and other complications considered excessive or unacceptable by a specialized physician based on a reasonable risk/benefit ratio. Said compounds may optionally be encapsulated in "pharmaceutically acceptable" macromolecules or supramolecular structures or nanostructures. For the sake of clarity, the term "encapsulation" means a process by which a therapeutically-effective amount of the coordination compounds of Formula 1(a) and/or 1(b), establishes intermolecular bonds {e.g. van der Waals forces, hydrogen bonds) with the single units of a "nanocarrier" or with specific structural domains. As an example, the surface or the hydrophobic core of the nanocarrier (e.g., micelles), or the hydrophilic core {e.g., liposomes), or also the lipidic/polymeric layer.

Finally, within the scope of the present invention, the term "theranostic compound" or more generally "theranostic agent" will refer to the coordination compound according to this invention, the composition containing at least one of said coordination compounds, or also a pharmaceutical formulation made up of the said compound and/or composition, which combines therapeutic properties with regard to a pathology, preferably neoplastic pathologies, along with the property to be detectable by suitable devices/detectors, hence to be usable in association with diagnostic and imaging systems for patient follow-up in therapeutic treatments and, if possible, to take the necessary corrective action.

Coordination compounds

It is a first object matter of the present invention a new class of mononuclear Au-based and Cu- based coordination compounds, whose features are defined in the appended independent claim. Such compounds are described by one of the following general formulae (here also referred to as "Formula 1(a)" or "Formula 1(b)"):

1(a) 1(b)

Said mononuclear coordination compounds herein disclosed are neutral or ionic complexes whose charge is neutralized by at least one counter-ion G. According to Formula 1(a) or Formula 1(b) M, X and Y are independently selected and have the following meaning:

M identifies the metal center of the compound and is selected from Au(lll), Cu(ll) or Cu(lll), also briefly Cu(ll, III).

X represents a monoatomic neutral or ionic ligand, for example bromide, iodide, or is a donor atom that is part of a neutral or ionic ligand, for example oxygen in oxalate or sulfur in dithiocarbamate. X is selected from the group consisting of: CI, Br, I, F, N, S, O, P, C and Se. Y may be the same or different from X, and similarly to X it represents a monoatomic neutral or ionic ligand or a donor atom that is part of a neutral or ionic ligand. The integer n represents the charge of the complex which can range from -4 to +4, where the case n = 0 corresponds to a neutral complex.

The G symbol identifies at least one counter-ion having the total charge d, being an integer ranging from -4 to +4. Such counter-ion is present with a stoichiometric coefficient e, identified by the integer n/d (in absolute value) or zero (in the latter case of course the counter-ion is not present and also n=0). G is pharmaceutically acceptable ion, which, by way of example and not limitation, is selected among: selected among: CI-, I-, F-, Br-, CH ₃ C0 ₂ ^~ , PF ₆ ^" , BF ₄ ^~ , SbF ₆ ^" , [B{C ₆ H ₃ (CF ₃ ) ₂ } ₄ ] ^~ , [B(C ₆ F ₅ ) ₄ ] ^~ , OH ^" , S0 ₃ NH ₂ ^~ , nitrites and nitrates (e.g., N0 ₂ ^~ , N0 ₃ ^" ), acetates, phosphates (e.g., hexafluorophosphate, H ₂ P0 ₄ ^~ , P0 ₄ ^3~ ), sulfates (e.g., triflate, HS0 ₄ ^~ ), carbonates, perchlorates, acetylacetonates (e.g., hexafluoroacetylacetonate), propionate, glycolate, stearate, lactate, malate, pyruvate, tartarate, citrate, ascorbate, palmitate, maleate, hydroxymaleate, phenylacetate, glutamate, benzoate, salicylate, sulfanilate, 2-acetoxybenzoate, fumarate, toluenesulfonate, methanesulphonate, ethane-1 ,2-disulfonate, trifluoromethanesulfonate, oxalate, malonate, succinate, glutarate, adipate, pimelate or isethionate, Na ⁺ , K ⁺ , Mg ²⁺ . However, the text " Remington's pharmaceutical Sciences, 17 th ed." (Mack Publishing Company) reports other chemically equivalent salts that can be used.

Alternatively, G represents at least one counterion generated by the synthesis of the coordination compound and may be a halide or a complex itself, preferably selected from: CI-, Br-, I-, AuX ₂ ^~ , AuX ₄ ^" (X = CI, Br); or other ones that are chemically equivalent.

Depending on the choice of the metal center and the donor atoms as well as the ligands (as it is well known, for example, in the case of halide ligand the donor atom coincides with the ligand itself), the compounds according to the present invention have different coordination geometries, for example square-planar, tetrahedric, pyramidal, or one of the previously distorted-structure geometries.

For the sake of clarity, in the Formula l(a) and Formula l(b ), the stylized arch connecting the S- donor atoms indicates a bidentate chelating dithiocarbamato ligand (DTC), in compliance with the usual chemical notation. In particular, in the mononuclear compounds described in Formula l(a), the arch connecting the two S-atoms represents a first dithiocarbamato (DTC) ligand, while the arc connecting X with Y represents a bidentate chelating ligand, which optionally represents a second DTC ligand, in the case where X = Y = S. In the mononuclear compounds described in the Formula l(b), there is only one DTC ligand, while the bidentate chelating ligand linking X with Y is absent. Said first or second dithiocarbamic chelating ligand (DTC) may have a closed (cyclic) or a open (e.g. linear or branched) structure.

In some embodiments, said first or second DTC ligand has a closed structure such as that depicted below, which is presented by way of example but not limitation of the present invention:

Such structure comprises groups Ri , R ₂ , R ₃ and R ₄ and optionally one R ₅ group. The Ri group and - if present - the R ₅ group, are bound to the dithiocarbamic nitrogen atom and to the R ₂ and R ₄ groups, respectively; the remaining R, groups are bound to the next and the previous group in the cyclic structure. If R ₅ is absent, R ₄ is directly bound to the dithiocarbamic nitrogen atom. All the bonds involving the R, groups, where i is an integer ranging from 1 to 5, may be single or double.

Optionally, the DTC ligand with the closed structure herein described comprises a glucide or carbohydrate T, which is bound to at least one of said R, groups directly or through a unit A by respectively T-R, bonds or T-A-R, bonds, which can be single, double or triple. Depending on the situation, the nature of said bonds may be: C-C, C-O, O-C, C-N, N-C, C-S, S-C, C-P, P-C, C-Se, Se-C.

The unit A is made up of an atom or a functional group or a spacer, meaning with this term a molecular fragment properly designed to join the glucidic moiety (T) with the cyclic structure described above, for example -COOCH ₂ CH ₂ O-CH ₂ CH ₂ O-CH ₂ CH ₂ O-CH ₂ CH ₂ O- or - CH ₂ CH=CHCH ₂ CH ₂ - or also -COOCH2CH2CH2CH2CH2CH2. However, for the unit A, other chemically-equivalent molecular fragments may be selected by the expert of the branch.

In other embodiments, said first or second DTC ligand has an open structure of the type depicted below by way of example, but not limitation:

In this case, the structure comprises a terminal group R linked to the dithiocarbamic nitrogen atom, and optionally one or more R ₂ , R ₃ , R ₄ and R ₅ groups.

If R ₂ is present, it represents a terminal group which can be bound to R ₃ or R ₄ or R ₅ or directly to the dithiocarbamic nitrogen atom, depending on which groups R, (i = 3, 4 or 5) are absent or not. If R ₂ is present, it represents a terminal group which may be linked to R ₃ , R ₄ , or R ₅ or directly to the said dithiocarbamic nitrogen atom, depending on which R, groups (i = 3, 4 or 5) are absent or not. If present, the R ₃ group is bound to R ₂ , or alternatively R ₃ is a terminal group when R ₂ is absent. In both cases, R ₃ is bound to R ₄ or R ₅ , or to said nitrogen atom, according to which group (among R ₄ or R ₅ ) is absent or not. Similarly, the R ₄ group, if present, is a terminal group and is bound to R ₅ or to said nitrogen atom; alternatively, R ₄ is bound to R ₅ or to said nitrogen atom and is bonded to R ₃ or R ₂ , depending on whether the R ₃ or R ₂ groups are absent or not. Finally, the R ₅ group, when present in the structure, is a terminal group and is linked to said nitrogen atom or alternatively it is bound to R,, according to which R, (i = 2, 3 or 4) groups are absent or not. All the bonds involving the R, groups, where i is an integer from 1 to 5, can be single, double or also triple.

Optionally, the DTC ligand with the open structure herein described comprises at least one glucide or a carbohydrate T. Said unit T is linked to said dithiocarbamic nitrogen atom or to at least one of the said R, groups (where i is an integer from 1 to 5) directly with respectively T-N or T-R, bonds, or alternatively via a unit A, by T-A-N or T-A-R, bonds. Depending on the cases, said bonds may be single, double or triple, and of the type: C-C, C-O, O-C, C-N, N-C, C-S, S-C, C-P, P-C, C-Se, Se-C. Also in this case, the unit A may be an atom or a functional group or a spacer, as well as the unit A is made up of other chemically-equivalent molecular fragments. In both types of structures (closed or open) of said first or second chelating DTC ligands, said unit A or said R, group (where i is an integer ranging from 1 to 5) are preferably selected from: an atom such as H, C, O, N, S, P, Se or a group selected among -CH, -CH ₂ , -CH ₃ , -C(CH ₃ ) ₃ , - NH, -NH ₂ , -NHR _S , -NR _s2 , -S-S-, -SH, -PH, -OH, -COOH, -CH-Br, -CHCH ₂ NH ₂ , -CHCH ₂ OH, - CHCH ₂ NH-, -CHCH ₂ 0-, (-CN), -CF ₃ , -C ₂ H ₅ , -C ₂ H ₄ , -C ₄ H ₉ , -C ₃ H ₇ , -C ₃ H ₆ , -C ₃ H ₆ OH, -C ₄ H ₈ , -N0 ₂ , - CH ₂ OH, -C ₂ H ₄ OH, -C ₄ H ₈ OH, -C(OH), -C(OH)H ₂ , -C(OH)H; -S0 ₂ , -COO-, -N(CH) ₃ -, -CHN(CH), - NN(CH),-NCHNCH-, -N(CH) ₂ N-, -CHNHCH-, -NH(CH), -NHCHN-, -NHNCH-; -CONH-, -CONH ₂ , -CONHR _s -CONR _s2 , (-0-C(0)-R _s ), where R _s indicates substituent groups of the type: aliphatic, alkyl, halo-alkykl, cycloalkyl, alkenyl, alkynyl, aryl, etero-aryl, etero-aliphatic, aromatic, etero- aromatic, aliphatic-aromatic, eteroaliphatic-eteroaromatic, cycloaliphatic, eterocycloaliphatic, esteric, amidic, sulphonamidic, carbonylic, acetyl, ethyl, propylic, butilyc, isopropylic, acylic, ureidic, thioureidic, thiolate, imine, halogens, ethers, nitro groups, nitrile, aryl, benzyl, sulphonamidic, saturated linear or branched C1 -C18 alkylic optionally substituted with one or more R _s groups or including one or more unsaturated bonds, a group of the type -(CH ₂ ) _m , - (CH ₂ 0) _m , -(CH ₂ CH ₂ S) _m , (CH ₂ CH ₂ NH) _m or (CH ₂ CH ₂ 0) _m , (CH ₂ CH ₂ N) _m where m represents an integer greater than 1 , or it is a a combination thereof.

Depending on the needs, as unit A or groups R, it is possible to use molecular fragments being chemically-equivalent to those those herein reported by way of example, but not limitation of the present invention. In addition, in some embodiments, combinations of the indicated species are possible. Furthermore, said the first or second chelating DTC ligand may contain in the unit A or in the R, groups chemical groups in salified form comprising pharmaceutically acceptable counterions {e.g., -NH ₃ ⁺ CI ^" ). It will be apparent to the skilled in the art that the unit A or the various R, groups may be variously substituted, in any combination and position, with one or more of said atoms or said groups. Similarly to the coordination compound, the first or the second chelating DTC ligand may also a priori have different isomeric forms. Hence the herein disclosed formulae are intended to include any form of isomerism, preferably coordination isomers, structural isomers, conformational isomers, optical isomers such as enantiomers and/or diastereoisomers, mixtures thereof, as racemic mixtures or in various ratios.

Again with reference to both closed or open structures of the first or the second chelating dithiocarbamato (DTC) ligand, said glucide or carbohydrate T is preferably a monosaccharide or a deoxy-monosaccharide, in particular a triose, a tetrose, a pentose, an esose, an eptose. By way of example, but not limitation, said glucide or carbohydrate T is selected from the group consisting of: glucose, galactose, mannose, xylose, rhamnose, arabinose, glucosamine, galactosamine, mannosamine, fructose, fructosamine, ribose, ribulose, sedoheptulose, erythrose, threose, erythrulose, allose, altrose, lixose, gulose, idose, talose. Alternatively, said glucide or carbohydrate T is a natural or synthetic polysaccharide, also in deoxy-carbohydrate form, for example maltose, cellobiose, lactose, trealose, sucrose, amylose, amylopectin.

In the case of the closed-structure DTC ligands, the T-R, or T-A-(R,) bond (where i is an integer ranging from 1 to 5) takes preferably place in at least one of the carbon positions of the T moiety, preferably in the positions C1 or C2 or C3 or C4 or C6, for the hexoses, and preferably in the C1 or C2 or C3 or C5 positions for pentoses.

In the case of the open-structure DTC ligands, the T-N or T-R, bond, or T-A-N or T-A-R, bond (where i is an integer ranging from 1 to 5) occurs preferably in the C1 or C2 or C3 or C4 or C6 positions for the hexoses, and preferably in the C1 or C2 or C3 or C5 positions for pentoses.

The first or the second chelating DTC ligand are symmetrical bidentate ligands whose chelating function is generally characterized by a negative q charge {q = -1 ). In light of the choice of the R, groups, of the unit A and the glucide T, the ligand may have an overall neutral {e.g., zwitterionic), positive or negative charge.

Moreover, taking into account both closed and open structures of the first or second chelating DTC ligand, and with reference to compounds of both the first embodiment and the second embodiment (i.e. containing carbohydrates T in the DTC ligand), one or more functional groups can be suitably protected during the synthetic process. Well-known groups are available for the protection of hydroxyl, amine, amide and carboxylic acid groups, as well as the conditions in which protection and deprotection can occur, even in so-called orthogonal conditions. In particular, protecting groups are introduced during the synthesis to avoid undesirable side- reactions and may be removed or not at the end of the synthetic procedure. In the second case, the new herein disclosed compounds may contain protective groups, even mutually different, in order to modulate the in vivo therapeutic profile, for example in terms of reactivity, solubility, stability and bioavailability. For example, one or more of the hydroxyl groups (also known as alcoholic) of one or more cancer-targeting moieties T of the second embodiment can be functionalized with equal or different protecting groups chosen, for example, from silyl ethers {e.g., trimethylsilyl ether or dimethyltertbutylsilylether) or esters {e.g., acetate, pivalate, propionate, carbonate, phosphate, butyrate). These concepts are in part summarized in the structure of the hexose shown below only by way of example but not limitation of the present invention.

In particular, the abovementioned protecting groups, identical or different, are indicated here by the notation R ₆ ; the substituent in position C1 may have an a or β conformation, and this monosaccharide binds, directly or through the unit A, to said R, groups or to the dithiocarbamic nitrogen atom in position C2 (as indicated by the black rectangle). For a pentose, depicted below only by way of example, but not limitation of the present invention, the protecting groups, equal or different, are again indicated by the notation R ₆ ; the substituent in position C1 may have an a or β conformation, and this monosaccharide binds, directly or through the unit A, to said R, groups or to the dithiocarbamic nitrogen atom in position C5 (as indicated by the black rectangle).

From the above description, it is clear that the first and the second chelating dithiocarbamato (DTC) ligand may be either equal to or different from each other. In the first case, the coordination compound is referred to as homoleptic, while in the latter it is heteroleptic. Examples of homoleptic compounds (Examples 6-13) and heteroleptic compounds (Example 21 ) will be described below, by way of example but not limitation.

SYNTHESIS AND CHARACTERIZATION OF THE COORDINATION COMPOUNDS

It is another subject matter of the present invention a process for the synthesis of the coordination compounds of general formula I (a) and l(b), whose features are set forth in the enclosed independent claim.

In the first preferred embodiment, herein described by way of example, but not limitation of the present invention, the coordination compounds having the general formula I (a) and l(b ) may be conveniently synthesized by a process including at least the following steps:

a) Preparation and optional isolation of the dithiocarbamato ligand (DTC);

b) Coordination of the DTC ligand to one specific metal center; c) Isolation of the coordination compound synthesized during step b).

This process may optionally include a further step d) related to the purification and drying of the coordination compound obtained at the end of the step c).

a) Preparation and isolation of the dithiocarbamato ligand (PTC)

The synthesis of the dithiocarbamato ligands (DTC) is carried out at a temperature ranging from -30 and 60 °C in water, or methanol, or dry THF via reaction between an amine precursor and carbon disulfide (CS ₂ ), optionally in the presence of a base, such as KOH or sodium tert- butoxide, or an excess of said amine precursor. In the case of some amines, it is preferable to work under inert atmosphere, using well-known equipment and techniques. Subsequently, the volume of the solvent is reduced and the DTC ligand can be isolated via precipitation or co- precipitation by adding diethyl ether, washed with diethyl ether and dried under vacuum in presence of P ₂ 0 ₅ .

By means of this synthetic strategy, which yields the isolation of pure DTC ligands (for example, as sodium salt, potassium salt or with the precursor amine under the form of ammonium), the present inventors have inventively achieved a number of remarkable advantages over the state of the art. First of all, this allows an improvement in the yield of the subsequent complexation reaction. Moreover, the DTC salt can be tested in vitro for its biological activity, in order to demonstrate that the antitumor activity is mediated by the coordination compound as a whole and not just by the ligand (or the metal center).

b) Coordination of the DTC ligand to a specific metal center

The synthesis of the coordination compound of general formula I (a) and/or l(b) is carried out in water or in an organic solvent, and it involves the coordination of the dithiocarbamato ligand (DTC), which has been optionally isolated in the previous step, to a selected metal center among Cu(ll,lll), and Au(lll). In the case of some compounds, it is preferable to work under inert atmosphere using well-known equipment and techniques.

The metal center is selected starting from the corresponding precursors, preferably chlorides or metal-halide salts, or complex salts, for instance copper chloride in the case the selected metal center is Cu(ll,lll). Alternatively, the precursors are metal derivatives with the metal center presenting a lower or higher oxidation state, such as organometallic-, amino-, thioether- precursors, or phosphine derivatives, or alternatively some of said coordination compounds can be themselves precursors, useful for the synthesis of other complexes.

During this step, contrast agents can be advantageously integrated in the coordination compound according to the invention in the form, for example, of radioisotopes such as ¹¹ C, ¹⁸ F, ⁶⁴ Cu, ¹⁹⁸ Au, ¹²⁷ l, ¹²⁹ l, ¹³¹ 1. In particular, these isotopes can be included in the DTC ligand, or they may coincide with the metal center or also introduced into the counter-ion. As it will be more clearly described in following, these contrast agents allow to combine the treatment of the neoplastic diseases with the diagnosis.

c) Isolation of the coordination compound synthesized during the step b) The isolation of the compound synthesized in the previous step b) proceeds via usual separation techniques, preferably filtration followed by reduction of the volume of water, or of said solvent, and by precipitation with ethyl ether. Alternatively, water or said solvent is evaporated under reduced pressure, in order to obtain the coordination compound of general formula 1(a) and/or 1(b), or a mixture containing said coordination compound.

d) Purification and drying of the coordination compound

During this step, the purification is optionally carried out using techniques well-known to the skilled in the art, for instance by chromatography, precipitation from organic solvent, washing with water or organic solvents and drying of said coordination compound.

The following sections describe further details of the process described in the step b), related to the coordination of the DTC ligand to a specific metal center.

Preparation of the compounds with M= Cu(lll), Au(lll) and X=Y=Br, CI, I

For the compounds obtained from the formula l(b) with M= Cu(lll) or Au(lll) e X=Y=Br, CI, I two approaches are possible based on the reactivity of the ligand under consideration.

The first approach consists in the oxidative addition of the halide Br ₂ or Cl ₂ to the corresponding Au(l)-DTC precursor of the type ([Au ₂ (DTC) ₂ ]), that is synthesized through an in situ reduction of an Au(lll) salt, such as NaAuCI ₄ -2H ₂ 0, with Na ₂ S0 ₃ in a saturated aqueous saline solution forming the Au(l) derivative ([CI-Au-CI] ^" ). This reaction is followed by the addition of 1 eq. of DTC ligand, leading to the formation of a precipitate that is dried under reduced pressure in presence of phosphoric anhydride. The oxidative addition is carried out in dichloromethane/chloroform solvent mixture (50:50% v/v) under reflux. After about one hour, the volume is reduced, and the product is precipitated by the addition of diethyl ether.

In the second approach, the coordination of the DTC ligand to the AuCI ₃ (py) or AuBr ₃ (py) (py=pyridine) precursor, is carried out in organic solvents, or in a mixture thereof, preferably DCM under reflux. The precursor AuX ₃ (py) is obtained by adding 1 eq. of pyridine to the corresponding NaAuX ₄ salt (X= CI, Br, I) in water, leading to the formation of a precipitate. The product is then centrifuged and can be washed optionally with water or ether and dried under reduced pressure.

In the case of X=Y=I, the Au(lll) complexes of the type [AuX ₂ (DTC)] were prepared from the corresponding [AuCI ₂ (DTC)] complex. In particular, the di-chloro compound was dissolved in

DCM and let to react with Kl in water. The so-obtained biphasic mixture is then kept under stirring at room temperature for three hours. The course of the reaction is followed by means of

TLC. Once completion, the organic phase is transferred in a separatory funnel and separated.

The combined organic phases were then anhydrified with Na ₂ SO and filtered. Then, the solvent was reduced and the product is precipitated with the addition of n-hexane. The obtained solid was isolated and dried under reduced pressure in the presence of P ₂ 0 ₅ .

Advantageously, such approaches allow for greater yield, in some cases even higher than 90%, compared to known syntheses. Preparation of the compounds with M= Cu(lll) and X= Y=Br, CI

For the coordination compounds obtained from the formula (I) with M = Cu(lll) and X=Y=Br or CI two strategies are possible. In the first, a defined compound of general structure 1(a) of the type [Cu(DTC) ₂ ] with M= Cu(ll) is dissolved in an organic solvent, preferably halogenated, and to this solution at least 1 equivalent of a halogenating agent, preferably thionyl halide (SOCI ₂ or SOBr ₂ ), is added.

In the second strategy, an excess of solid Cu is added to a solution of a defined compound of general structure I (a) of the type [Cu(DTC) ₂ ] with M= Cu(ll) dissolved in an organic solvent, preferably CS ₂ ; such suspension is allowed to shake for at least 8 hours. The resulting solution is then filtered and an intermediate of the type [Cu'(DTC)] is isolated, for example by precipitation with organic solvent, preferably diethyl ether. Said intermediate is subsequently dissolved in an organic solvent, preferably halogenated, and put to react with at least one equivalent of halogenated oxidizing agent, preferably bromine Br ₂ or chlorine Cl ₂ .

Preparation of the compounds with M= Cu(ll)

For the coordination compounds obtained from the formula l(a) with M= Cu (II) and X=Y=S, the synthesis involves the coordination of the DTC ligand (prepared in the above step, 2 eq.) to the metal precursor, preferably but not exclusively, copper(ll) chloride in a stoichiometric metal- ligand ratio of 1 : 2. Typically, the reaction is carried out in water or methanol at room temperature, resulting in the precipitation of the neutral compound [Cu(DTC) ₂ ]. The compound is then centrifuged, washed with water and methanol and dried under vacuum with P ₂ 0 ₅ .

Preparation of the compounds with M= Au(lll), Cu(lll) e X=Y=S

For the coordination compounds obtained by the formula l(a) with M= Au(lll) or Cu(lll), X=Y=S, saturating with S-donor atoms the coordination sphere of the derivative of general formula l(b), preferably dissolved in dichloromethane (DCM) by addition of another equivalent of DTC ligand (dissolved in methanol) at room temperature. The cationic complexes of the type [M(DTC) ₂ ] ⁺ with, for example, M=Au(lll) and AuCI ₄ ^" or AuBr ₂ ^" as a counterion, are obtained from the Au(lll) precursor [AuPyX ₃ ] (X= CI, Br e Py= pyridine) by adding 0.5 eq. or 1 .5 eq. of the DTC ligand, respectively. In the enclosed Figures 2(D) and Figure 2(E), the solved X-ray structures of two compounds of this class are reported as non-limitative examples.

The counterion G can be advantageously chosen or replaced using techniques well-known to the skilled in the art, in order to optimize the pharmaceutical profile in terms of antitumor activity, "off-target" toxicity, solubility and stability.

Advantageously, through the syntheses herein described, which allow to obtain intrinsically pure compounds, the present inventors have overcome in a new and inventive manner the limitations in the state of the art highlighted above.

EXAMPLES OF COMPLEXES ACCORDING TO THE FIRST EMBODIMENT

By way of example, but not limitation of the present invention, some specific examples of coordination compounds having formula l(a) or l(b) are reported below. In the first preferred embodiment of the present invention such complexes do not contain a cancer-targeting moiety in the form of carbohydrate. Such compounds contain, for example, dithiocarbamato ligands derived from: piperidine, morpholine, L-proline methyl ester, L-proline ferf-butyl-ester, pyrrole, and which for brevity are named, respectively, as PipeDTC, MorphDTC, ProOMeDTC, ProOtBuDTC, PyrrDTC.

The compounds were characterized by means of various techniques, including elemental analysis, NMR spectroscopy, FT-IR spectrophotometry and ESI-MS mass analysis. By way of example, and not limitation, the enclosed Figure 2 shows the structures of some of these compounds solved by X-ray diffraction.

Example 1 : [AuCI ₂ (PipeDTC)J

Appearance: dark yellow solid; Yield: 93 %

Anal. Calc. for C ₅ H ₈ AuCI ₂ NS ₂ (MW = 428.15 g mol ^"1 ): C 16.83; H 2.35; N 3.27; S 14.98. Found: C 16.86; H 2.37; N 3.21 ; S 15.02.

1 H-NMR (DMSO-d ₆ , 600 MHz): δ (ppm) = 1 .72 (s, 6H, H ₍₃₎ + H ₍₄₎ + H ₍₅₎ ), 3.82 (s, 4H, H ₍₂₎ + H ₍₆₎ ). Medium FT-IR (KBr): v (cm ¹ ) = 2944.60, 2858.64 (v _a , C-H); 1581 .42 (v _a , N-CSS); 947.36 (v _a , CSS). Far FT-IR (nujol): v (cm ¹ ) = 539.66 (v _s , CSS); 366.20 (v _a , Au-S); 349.71 (v _a , Au-CI); 334.59 (v _s , Au-S); 315.67 (v _s , Au-CI).

Example 2: [AuBr ₂ (PipeDTC)

Appearance: orange needles; Yield: 96 %

Anal. Calc. for C ₆ H ₁₀ AuBr ₂ NS ₂ (MW = 517.05 g mol ^"1 ): C 13.94; H 1 .95; N 2.71 ; S 12.40. Found C 13.99; H 1 .98; N 2.73; S 12.42.

¹ H-NMR (DMSO-d ₆ , 600 MHz): δ (ppm) = 1 .72 (s, 6H, H ₍₃₎ + H ₍₄₎ + H ₍₅₎ ), 3.79 (s, 4H, H ₍₂₎ + H ₍₆₎ ). Medium FT-IR (KBr): v (cm ¹ ) = 2941 .65 (v _a , C-H); 1573.91 (v _a , N-CSS); 941 .52 (v _a , CSS).

Far FT-IR (nujol): v (cm ¹ ) = 538.90 (v _s , CSS); 369.79 (v _a , Au-S); 350.61 (v _s , Au-S); 239.1 1 (v _a Au-Br); 223.85 (v _s , Au-Br).

The X-ray structure is reported in the enclosed Figure 2(A) unit.

Example 3: [Aul ₂ (PipeDTC)J

Appearance: violet solid; Yield: 75 %

Anal. Calc. for C ₆ H ₁₀ Aul ₂ NS ₂ (MW = 61 1 .044 g mol ^"1 ): C 1 1 .79; H 1 .65; N 2.29; S 10.49. Found: C 1 1 .82; H 1 .67; N 2.33; S 10.51 . ¹ H-NMR (DMSO-d ₆ , 600 MHz): δ (ppm) = 1 .72 (m, 6H, H ₍₃₎ + H ₍₄₎ + H ₍₅₎ ), 3.73 (m, 4H, H ₍₂₎ + H ₍₆₎ ). Medium FT-IR (KBr): v (cm ¹ ) = 2942.08, 2864.80 (v _a , C-H); 1558.61 (v _a , N-CSS); 942.62 (v _a , CSS). Far FT-IR (nujol): v (cm ¹ ) = 504.20 (v _s , CSS); 359.05 (v _a , Au-S); 341 .44 (v _s , Au-S).

Example 4: [AuCI ₂ (ProOMeDTC)J

Appearance: orange solid; Yield: 89 %

Anal. Calc. for C ₇ H ₁₀ AuCI ₂ NO ₂ S ₂ (MW = 472.16 g mol ^"1 ): C 17.81 ; H 2.13; N 2.97; S 13.58. Found: C 17.86; H 2.22; N 2.90; S 13.65.

¹ H-NMR (DMSO-d ₆ , 300.13 MHz): δ (ppm) = 2.20 (m, 20H, H ₍₃₎ + H ₍₄₎ ), 3.28-3.98 (m, 25H, H ₍₅₎ + 0-CH ₃ ), 5.02-5.38 (m, 5H, H ₍₂₎ ).

Medium FT-IR (KBr): v (cm ¹ ) = 2951 .38 (v _a , C-H); 1746.56 (v, C=0); 1559.95 (v _a , N-CSS); 1 173.93 (v _a, C-OMe); 979.24 (v _a , CSS). Far FT-IR (nujol): v (cm ¹ ) = 546.77 (v _s , CSS); 381 .91 (v _a , Au-S); 359.01 (v _a , Au-CI); 339.07 (v _s , Au-S); 318.79 (v _s , Au-CI).

Example 5: [AuBr ₂ (ProOtBuDTC)J

Appearance: orange needles; Yield: 90 %

Anal. Calc. for C ₁₀ H ₁₆ AuCI ₂ NO ₂ S ₂ (MW = 603.14 g mol ¹ ): C 19.91 ; H 2.67; N 2.32; S 10.63. Found: C 20.02; H 2.70; N 2.29; S 10.71 .

¹ H-NMR (DMSO-d ₆ , 300.13 MHz): δ (ppm) = 1 .41 -2.26 (m, 65H, H ₍₃₎ + H ₍₄₎ + 0-C(CH ₃ ) ₃ ), 3.21 - 4.02 (m, 10H, H ₍₅₎ ), 4.36-5.30 (m, 5H, H ₍₂₎ ).

Medium FT-IR (KBr): v (cm ¹ ) = 2977.36 (v _a , C-H); 1736.46 (v, C=0); 1559.96 (v _a , N-CSS); 1 146.69 (v _a, C-OfBu); 952.67 (v _a , CSS).

Far FT-IR (nujol): v (cm ¹ ) = 540.70 (v _s , CSS); 379.35 (v _a , Au-S); 344.53 (v _s , Au-S); 238.34 (v _a , Au-Br); 219.02 (v _s , Au-Br).

Example 6: [Cu(ProOMeDTC) ₂ ]

COOMe

Appearance: dark green solid; Yield: 80 % R.f. (silica gel, CH ₂ CI ₂ ): 0.50

Anal. Calc. for Ci ₄ H ₂ oCuN ₂ 0 ₄ S4 (MW = 472.13 g mol ^"1 ): C 35.62; H 4.27; N 5.93; S 27.17. Found: C 35.83; H 4.13; N 5.81 ; S 27.47.

¹ H-NMFt (CDCI ₃ , 300.13 MHz): δ (ppm) = 2.1 1 -2.93 (m, 8H, H ₍₃₎ + H ₍₄₎ ), 3.94 (m, 6H, 0-CH ₃ ). Medium FT-IR (KBr): v (cm ¹ ) = 2951 .87 (v _a , C-H); 1750.79 (v, C=0); 1471 .56 (v _a , N-CSS); 1 153.76 (v _a, C-OMe); 939.75 (v _a , CSS). Far FT-IR (nujol): v (cm ¹ ) = 565.71 (v _s , CSS); 342.87 (v _a , Cu-S); 279.96 (v _s , Cu-S).

ESI-MS m/z, [M ⁺ ] - Found (calc): 470.97 (470.96).

The X-ray structure is reported in the enclosed Figure 2(B).

Example 7: [CufProOtBuDT J

COOtBu

Appearance: brown solid; Yield: 74 %

R.f. (silica gel, CH ₂ CI ₂ ): 0.72

Anal. Calc. for C ₂ oH ₃₂ CuN ₂ 0 ₄ S4 (MW = 556.29 g mol ¹ ): C 43.18; H 5.80; N 5.04; S 23.06. Found: C 43.42; H 5.92; N 4.90; S 23.21 .

¹ H-NMR (CDCI ₃ , 300.13 MHz): δ (ppm) = 1 .57 (s, 18H, 0-C(CH ₃ ) ₃ ), 1 .99-2.83 (m, 8H, H ₍₃₎ +

Medium FT-IR (KBr): v (cm ¹ ) = 2974.81 (v _a , C-H); 1733.37 (v, C=0); 1469.68 (v _a , N-CSS); 1 148.53 (v _a, C-0 Bu); 930.08 (v _a , CSS). Far FT-IR (nujol): v (cm ¹ ) = 568.57 (v _s , CSS); 340.1 1 (v _a , Cu-S); 276.1 1 (v _s , Cu-S).

ESI-MS m/z, [M ⁺ ] - found (calc): 555.06 (555.05).

The X-ray structure is reported in the enclosed Figure 2(C).

Example 8: [CufPi

Appearance: dark brown solid; Yield: 90 %

R.f. (silica gel, CH ₂ CI ₂ ): 0.92

Anal. Calc. for C ₁₂ H ₂₀ CuN ₂ S ₄ (MW = 384.1 1 g mol ¹ ): C 37.52; H 5.25; N 7.29; S 33.39. Found: C 37.54; H 4.77; N 7.10; S 33.18.

¹ H-NMR (CDCI ₃ , 300.13 MHz): δ (ppm) = 0.33 (s, 8H, H ₍₃₎ + H ₍₅₎ ), 1 .17 (s, 4H, H ₍₄₎ ).

Medium FT-IR (KBr): v (cm ¹ ) = 2941 .17, 2850.28 (v _a , C-H); 1501 .54 (v _a , N-CSS); 947.25 (v _a , CSS). Far FT-IR (nujol): v (cm ¹ ) = 563.41 (v _s , CSS); 353.57 (v _a , Cu-S); 291 .76 (v _s , Cu-S).

ESI-MS m/z, [M ⁺ ] - found (calc): 382.98 (382.98) Example 9: [CufMorphDT J

Appearance: brown solid; Yield: 94 %

R.f. (silica gel, CH ₂ CI ₂ ): 0.42

Anal. Calc. for Ci ₀ H ₁₆ CuN ₂ O ₂ S ₄ (MW = 388.07 g mol ¹ ): C 30.95; H 4.16; N 7.22; S 33.05. Found: C 31 .08; H 4.18; N 7.09; S 32.94.

Medium FT-IR (KBr): v (cm ¹ ) = 2968.97, 2853.40 (v _a , C-H); 1485.33 (v _a , N-CSS); 1 1 10.23 (v _a, C-O); 1010.40 (v _a , CSS). Far FT-IR (nujol): v (cm ¹ ) = 558.69 (v _s , CSS); 338.25 (v _a , Cu-S); 291 .38 (v _s , Cu-S).

ESI-MS m/z, [M ⁺ ] - found (calc): 386.94 (386.94).

Example 10: [CufPyrroleDTQrf

Appearance: dark brown solid; Yield: 88 %

R.f. (silica gel, CH ₂ CI ₂ ): 0.86

Anal. Calc. for C ₁₀ H ₈ CuN ₂ S ₄ (MW = 347.99 g mol ¹ ): C 34.51 ; H 2.32; N 8.05; S 36.86. Found: C 34.61 ; H 2.29; N 8.08; S 36.68.

Medium FT-IR (KBr): v (cm ¹ ) = 3131 .02 (v _a , C-H); 1472.85, 1409.66 (v, C=C ring); 1333.66 (v _a , N-CSS); 1012.56 (v _a , CSS); 836.97 (ω, C-H); 729.40 (δ, C-H). Far FT-IR (nujol): v (cm ¹ ) = 591 .99 (v _s , CSS); 41 1 .07 (v _a , Cu-S); 338.87 (v _s , Cu-S).

ESI-MS m/z, [M ⁺ ] - found (calc): 346.90 (346.89).

Example 11: [AufPipeDTQrfCI

Appearance: yellow solid; Yield: 82 %

R.f. (silica gel, CH ₂ CI ₂ /MeOH 9:1 ): 0.12

Anal. Calc. for Ci ₂ H ₂₀ AuCIN ₂ S ₄ (MW = 552.98 g mol ¹ ): C 26.02; H 3.65; N 5.07; S 23.19. Found: C 26.07; H 3.71 ; N 5.19; S 23.1 1 .

¹ H-NMR (DMSO-d ₆ , 600 MHz): δ (ppm) = 1 .74 (m, 12H, H ₍₃₎ + H ₍₄₎ + H ₍₅₎ ), 3.83 (m, 8H, H ₍₂₎ +

Medium FT-IR (KBr): v (cm ¹ ) = 2936.83, 2861 .75 (v _a , C-H); 1560.51 (v _a , N-CSS); 951 .13 (v CSS). Far FT-IR (nujol): v (cm ¹ ) = 51 1 .54 (v _s , CSS); 414.36 (v _a , Au-S); 370.15 (v _s , Au-S).

ESI-MS m/z, [M-CI ⁺ ] - found (calc): 517.03 (517.02) Example 12: [AufMorphDT JBr

Appearance: orange solid; Yield: 86 %

Anal. Calc. for CioH ₁₆ AuBrN ₂ 0 ₂ S4 (MW = 601 .38 g mol ¹ ):

C 19.97; H 2.68; N 4.66; S 21 .33. Found: C 19.93; H 2.75; N 4.52; S 20.88

¹ H-NMR (DMSO-d ₆ , 300.13 MHz): δ (ppm) = 3.80-3.81 (m, 4H, H ₍₂₎ + H ₍₆₎ ), 3.85-3.87 (m, 4H,

Medium FT-IR (KBr): v (cm ¹ ) = 2983.60, 2927.54, 2869.24 (v _a , C-H); 1561 .66 (v _a , N-CSS); 1 108.57 (v _a, C-0); 993.49 (v _a , CSS). Far FT-IR (nujol): v (cm ¹ ) = 541 .58 (v _s , CSS); 357.80 (v _a , Au-S); 347.90 (v _s , Au-S);

ESI-MS m/z, [M-CI ⁺ ] - found (calc): 520.98 (520.97)

Example 13: [Au(ProOtBuDTC) ₂ ]Br

Appearance: orange solid; Yield: 84%

Anal. calc. for C ₂ oH3 ₂ AuBrN ₂ 0 ₄ S ₄ (MW=769.61 g mol ^"1 ): C, 31 .21 ; H, 4.19; N, 3.64; S, 16.67; Found: C, 31 .17; H, 4.20; N, 3.37; S, 16.47.

ESI-MS, [M] ⁺ : 689.09 m/z;

¹ H-NMR (CD ₂ CI ₂ , 400.13 MHz, TMS, δ/ppm): 1 .49 (s, 9H, C(CH ₃ ) ₃ ) 2.25, 2.52 (m, 4H, CH ₂ pos.3,4); 3.98 (m, 2H, CH ₂ pos.5); 4.78 (dd, 1 H, CH pos.2);

1 ³ C-NMR (CD ₂ CI ₂ , 100.67 MHz, TMS, δ/ppm): 196.25 (CSS);

Medium FT-IR (KBr, v max/cm ^"1 ): 2975 (v _a ,C-H); 1733 (v,C=0); 1535 (v _a ,N-CSS); 1221 (v,C- O(tBu)); 1 149, 837 (v _a,s, (OtBu)); 1003, 586 (v _a,s, CSS);

Far FT-IR (Nujol, v max/cm ^"1 ): 370(v _a,s ,Au-S).

SYNTHESIS AND CHARACTERIZATION OF GLYCO-CONJUGATED COMPLEXES

It is another object of the present invention a process for the glyco-conjugation of the coordination compounds according to the present invention, whose features are set forth in the enclosed independent claim.

In the second preferred embodiment, the coordination compounds of Formula l(a) and Formula l(b) contain dithiocarbamato ligands functionalized with carbohydrates which act as a selective cancer-targeting moiety towards cancerous cells in vivo, advantageously exploiting the Warburg effect.

The glycoconjugation process involves a number of synthetic steps for the functionalization of a specific amino precursor with a likewise specific carbohydrate. Such amino precursor is subsequently converted to the corresponding dithiocarbamato (DTC) ligand, through the phase a) of the procedure of the first embodiment. In particular, the synthesis involves the protection of the hydroxyl groups of carbohydrate with protecting groups which are orthogonal to the reaction conditions of the subsequent synthetic steps. The carbohydrate (e.g., glucose, mannose) is functionalized (e.g., in position 1 or 2) with a molecular fragment containing an amine, preferably secondary, which is able to react with CS ₂ to form a DTC ligand, ready for the subsequent complexation to the metal center (Au, Cu). Alternatively, such amine group or other functional group, for example -OH, is not directly used to prepare the dithiocarbamato ligand, but its reactivity could be exploited to bind a molecular fragment which, depending on the molecular design, may have different length and chemical composition. However, said molecular fragment must contain, after one or more synthetic steps, an amine group (that is, the precursor amine, as an example a proline) on which the CS ₂ -based reaction will be carried out to form the DTC ligand. The deprotection of protecting groups can be performed by means of chemical or biochemical methods including the use of enzymes or pseudoenzymes. Pseudoenzymes are generally referred to proteins, such as the HSA (Human Serum Albumin), which may hydrolyze, for example, ester substrates due to the presence of several nucleophilic residues (such as lysine) on their surface, but which do not return to the native state after the hydrolysis reaction.

Scheme 1. Example of functionalization in position CI: a) NaN3, acetone, 56°C, crystallization, 60%; b) H ₂ /Pd, MeOH/EtOAc, 98%; c) Z-Sar-OH, N-methyl morpholine, isobutylchloroformiate, TH F-dry, -15°C, 83%; d) NaOMe, MeOH-dry, acid resin, rt, 100%; e) TMS-CI, Hexamethyldisilazane, pyridine, CH ₂ CI ₂ , 0°C, flash chromatography, 85%; f) H ₂ /Pd, MeOH/EtOAc, 90%; g) CS ₂ , KOH, MeOH, 100%; h) AuX ₃ py (X=CI, Br; py= pyridine), CH ₂ CI ₂ , 42°C, flash chromatography, 40%; i) acid resin, CH ₂ CI ₂ , rt, 95%.

During the synthetic process, in addition to the glyco-conjugation, various types of reactions can be conducted. For example: nucleophilic substitution, peptide coupling, protection or deprotection processes, redox reactions, formation of iminic or nitrile intermediates, reduction with H ₂ , hydrolysis.

By way of example, but not limitation, the Scheme 1 reported below shows the synthesis of a dithiocarbamato ligand (a-g), bearing a glucose moiety functionalized in position 1 of the pyranosic ring (β-amido-glycoside). In the h-i steps, the complexation with an Au(lll) center occurs, followed by deprotection of the silyl protecting groups.

Similarly, the Scheme 2 reported below as a non-limitative example of the present invention shows the synthesis of a dithiocarbamato ligand (A-D) functionalized with a glucopyranosyl moiety, through the position 1 of the carbohydrate ring. Unlike the previous example, in which the glucose moiety is functionalized obtaining a β- D-A/-glucopyranosylamide, a DTC ligand bearing a β-D-O-glucopyranosyl fragment is isolated in this case. In the step F, the complexation with a Cu(ll) center occurs, followed by the purification through a C-18 column chromatography.

Scheme 2. Schematic representation of the synthesis of the β-D-glucoside-conjugated dithiocarbamato ligand as potassium salt (A-D). Synthetic procedure for Cu(ll) complexes with glycosylated dithiocarbamates as ligands (F). The wavy bonds in the carbohydrate moieties denote the presence of both the possible stereocenters in order to offer to the reader a general depiction incorporating the structures of all the glycosyl derivatives under investigation (CbZ= carboxybenzyl protecting group).

By way of example, the Scheme 3 reported below shows the synthesis of a dithiocarbamato ligand {c-g), being a glucose derivative, functionalized in position C-2 (glucosamide, namely an amide derivative of glucosamine). In h-i steps, the complexation to a Cu(ll) center occurs, followed by deprotection of the silyl protecting groups.

Scheme 3. Example of functionalization in C2: c) Z-Pro-OH, N-methyl morpholine, isobutylchloroformiate, TH F-dry, -15°C, 83%; d) NaOMe, MeOH-dry, acid resin, rt, 100%; e) TMS-CI, Hexamethyldisilazane, pyridine, CH ₂ CI ₂ , 0°C, flash chromatography, 85%; f) H ₂ /Pd, MeOH/EtOAc, 90%; g) CS ₂ , KOH, MeOH, 100%; h) CuCI ₂ , MeOH, flash chromatography; i) acid resin, CH ₂ CI ₂ , rt.

Scheme 4. Example of functionalization in position C3: i) Ac20/py, -20°C; ii) Tf20/py, -15°C, iii) NaN3, rt; iv) H2/Pd/C, rt.

Scheme 5. Exa mple of fu nctiona lization in C4: i) Bn Br/py, rt; ii) NaCN BH 3/TFA, 0°C; iii) MsCI, rt; iv) Na N3, 60-7CTC; v) H2/Pd/C, rt. By way of example, and not limitation, the schemes 4, 5 and 6 show the syntheses of carbohydrate derivatives having an amino function (-NH ₂ ) in C3, C4 and C6 positions, respectively. Such amine function can in turn be functionalized with a molecular fragment on which the dithiocarbamato group is synthesized, or alternatively, such amine group can be directly converted to dithiocarbamate by reaction with CS ₂ or may be advantageously modified in a different functional group, for example a secondary amine or an isothiocyanate, in order to conduct subsequent reactions for the bioconjugation of the metal.

Scheme 6. Exa mple of fu nctionalization in C6 : i) Ph3CCI, Bn Br, AICI3, rt; ii) MsCI, rt; iii) NaN3, 60°C; iv) H2/Pd/C, rt. By way of example, and not limitation, the Scheme 7 reported below displays the synthesis of a a-D-2-deoxyglucopyranoside.

Scheme 7. Example of functionalization in CI of a 2-deoxy-D-glucose: A) N-Methyl, N-carboxybenzyl ethanol 3-amine, acid resin, molecular sieves, acetonitrile, column chromatography 40% B) NaOMe (0.33 eq.), MeOH, rt, overnight, 98%; C) H2/Pd, MeOH/EtOAc 1:2, 2h, rt, 99%; D) CS2, KOH, H20, 6h, 0 °C, CIS- column chromatography, 34%; E) CuCI2- 2H20, MeOH, rt, C18-colu mn chromatography, 60%.

In the steps A-D, the synthesis of dithiocarbamato ligand bearing a C-1 functionalized glucoside with an ct-anomeric conformation is depicted. At the step E, the complexation with a Cu(ll) center occurs, followed by the purification through a C-18 column chromatography.

On the basis of the reaction schemes above disclosed, it will be apparent to those skilled in the art that only obvious changes to the procedure are required in case the functionalization involves other carbohydrates, or other positions (depending on the type of carbohydrate), or also in case the synthesis is designed to obtain different amino precursors.

The synthesis of the organic part, the amino-precursor of the carbohydrate-functionalized dithiocarbamato ligand, is particularly challenging. In fact, some synthetic approaches have not been successful.

EXAMPLES OF COMPLEXES ACCORDING TO THE SECOND EMBODIMENT

By way of example, but not limitation, hereinafter there are reported examples of coordination compounds according to the second embodiment i.e. containing glucides or carbohydrates in one or more dithiocarbamato ligands. Homoleptic complexes

Example 14: [AuBr ₂ (tetra O-acetyl-glycosyl-amido-ProlineDTC)]

Appearance: orange solid; Yield: 70 %

R.f. (silica gel, EtOAc): 0.65

Anal. Calc. for C ₂ oH ₂ 7AuBr ₂ N ₂ OioS2 (MW = 876.34 g-mol ^"1 ):

C 27.41 ; H 3.1 1 ; N 3.20; S 7.32; Found: C 27.48; H 3.28; N 3.31 ; S 7.55.

¹ H-NMR (CDCI ₃ , 300.13 MHz): δ (ppm) = 2.03, 2.08, 2.09, 2.17 (12H, s); 2.24-2.52 (4H, m); 3.78-3.88 (2H); 3.94 (1 H, m); 4.06-4.10 (1 H, ddd); 4.28-4.33 (1 H, ddd); 4.48-4.51 (1 H, ddd); 4.90 (1 H, t); 5.08 (1 H, t); 5.18 (1 H, t); 5.32 (1 H, t); 6.79 (1 H, m).

FT-IR (KBr): v (cm ¹ ) = 1748 (v, C=0); 1542 (v, C=0); 1664 (v _a , N-CSS)

Example 15: [AuCI ₂ (Galactopyranosyl-0-ethylamino-N-methyl-DTC)]

Appearance: light yellow solid; Yield: 45 %

Anal. Calc. for C ₁₀ H ₁₈ AuCI ₂ NO ₆ S ₂ (MW = 580.26 g-mol ^"1 ): C 20.70; H 3.13; N 2.41 ; S 1 1 .05. Found: C 20.65; H 3.26; N 2.55; S 1 1 .38.

¹ H-NMR (MeOD, 300.13 MHz): δ (ppm) = 3.26 (2H, m); 3.46 (1 H, m) 3.49 (1 H, m); 3.51 (1 H, m); 3.54 (3H, s); 3.65 (1 H, m); 3.69 (2H, m); 3.78 (1 H, m); 3.94-3.98 (1 H, m); 4.18 (1 H, d).

FT-IR: v (cm ¹ ) = 1648 (v _a , N-CSS); 385, 358 (v _a,s , Au-S); 345, 318 (v _a,s , Au-CI).

Example 16: [AuBr ₂ (N-mannopyranosyl-sarcosinamide-DTC)J

Appearance: light orange solid; Yield: 52%

Anal. Calc. for Ci ₀ H ₁₇ AuBr ₂ N ₂ O ₆ S ₂ (MW = 682.16 g-mol ^"1 ): C 17.61; H 2.51; N 4.11; S 9.40. Found: C 17.73; H 2.69; N 4.09; S 9.82.

¹ H-NMR (MeOD, 300.13 MHz): δ (ppm) = 3.46 (1H, m) 3.49 (1H, m); 3.51 (1H, m); 3.54 (3H, s); 3.65 (1 H, m); 3.78 (1 H, m); 3.94-3.98 (1 H, m); 4.18 (1 H, d); 4.48 (2H, s).

Medio FT-IR (KBr): v (cm ¹ ) = 1563 (v, C=0); 1652 (v _a , N-CSS).

Example 17: [Cu(tetra-0-Acetyl-glucopyranosyl prolyl amido DJC) ₂ ]

Appearance: brown solid; Yield: 97 %

Anal. Calc. for C^I- Cu^O^ (MW = 1102.68 g-mol ^"1 ): C 43.57; H 4.94; N 5.08; S 11.63. Found: C 43.81; H 4.82; N 5.15; S 11.94.

¹ H-NMFt (CDCI ₃ , 300.13 MHz): δ (ppm) = 2.03, 2.08, 2.09, 2.17 (12H, s); 2.18-2.36 (4H, m); 3.21-3.24 (2H); 3.78 (1H, m); 4.06-4.10 (1H, ddd); 4.28-4.33 (1H, ddd); 4.48-4.51 (1H, ddd); 4.90 (1 H, t); 5.08 (1 H, t); 5.18 (1 H, t); 5.32 (1 H, t); 6.79 (1 H, m).

FT-IR (KBr): v (cm ¹ ) = 1749 (v, C=0); 1540 (v, C=0); 1632 (v _a , N-CSS).

ESI-MS m/z, [M ⁺ ]- Found: 1101.19

Example 18: [Aubis(2-glucosamido-L-ProlineDTC)]N0 ₃

Appearance: light yellow solid; Yield: 52 %

Anal. Calc. for C ₂₄ H ₃₈ AuN ₅ Oi ₅ S4 (MW = 961.81 g mol ¹ ): C 29.97; H 3.98; N 7.28; S 13.34. Found: C 29.82; H 3.78; N 7.25; S 13.48.

¹ H-NMR (MeOD, 300.13 MHz): δ (ppm) = 2.12-2.18 (4H, m); 3.12 (1H, t); 3.38 (1H, m), 3.52 (2H, m); 3.58 (3H, m); 4.93 (2H, m); 6.69 (1 H, d).

Medium FT-IR (KBr): v (cm ¹ ) = 1538 (v, C=0); 1622 (v _a , N-CSS).

ESI-MS m/z, found: 899.12

Example 19: [Cu bis(N-methyl, O-ethylamino, glucopyranoside DTC].

Appearance: brown amorphous powder

Yield: 61 %

Anal. Calc. for C ₂ oH ₃₆ Cu ₂ N ₂ 0 ₁₂ S4 (MW = 688.31 g mol ¹ ): C 34.90; H 5.27; N 4.07; S 18.63. Found: C 34.08; H 5.25; N 3.12; S 18.20.

Medium FT-IR (KBr): v (cm ¹ ) = 1514 (v _a , N-CSS); 1077 (v _a , CO); 990 (v _a , CSS); 897 (v, OCO). Far FT-IR (nujol): v (cm ¹ ) = 565 (v _s , CSS); 357 (v _a , Cu-S); 291 (v _s , Cu-S).

ESI-MS m/z, [M] ⁺ found (calc): 687.05 (687.04).

Example 20: [Cu bis(N-methyl, O-ethylamino, 2-deoxyglucopyranoside DTC].

Appearance: brown amorphous powder

Yield: 55 %

Anal. Calc. for C ₂₀ H ₃₆ Cu ₂ N ₂ OioS ₄ (MW = 656.31 g mol ¹ ): C 36.60; H 5.53; N 4.27; S 19.54. Found: C 36.71 ; H 5.29; N 3.92; S 19.43.

Medium FT-IR (KBr): v (cm ¹ ) = 1516 (v _a , N-CSS); 1083 (v _a , CO); 992 (v _a , CSS); 903 (v, OCO). Far FT-IR (nujol): v (cm ¹ ) = 567 (v _s , CSS); 352 (v _a , Cu-S); 287 (v _s , Cu-S).

ESI-MS m/z, [M] ⁺ found (calc): 655.07 (655.05). Heteroleptic complexes

The examples of compounds reported above as merely illustrative of the present invention, are referred to homoleptic compounds. However, on the basis of the above-described syntheses, the present inventors have indeed disclosed a strategy for replacing the two coordination sites occupied by the X and Y ligands in the general structure 1(b), such as halide ions, with a bidentate DTC ligand, useful to form a homoleptic or heteroleptic coordination compound depending on said ligand is equal to or different from that already present in the coordination compound. This strategy also allows to combine the first and second embodiments, obtaining compounds in which only one ligand contains a carbohydrate, such as that of the Example 19 reported below as a non-limitative example, which was obtained starting from the compound of the previous Example 14 and substituting the two bromides with the piperidine DTC (pipeDTC) ligand.

In a surprising and advantageous way, this technique allows to obtain water-soluble cationic Cu(lll) and Au(lll) complexes, to modulate the solubility/hydrophilicity (increasing or decreasing it depending based on the nature of the second dithiocarbamato ligand undergoing metal coordination) of the final complex in physiological environment, to increase/decrease the redox reactivity of the metallic center (in terms of reduction potentials), to modulate the immunogenic response as well as the overall steric hindrance.

Example 21 : [Au(PipeDTC)(tetra-0-Acetyl-glucopyranosylamido-ProDTC)]CI.

Appearance: dark yellow solid; Yield: 79%

Anal. Calc. for C ₂₆ H ₃₇ AUCIN ₃ O ₁₀ S ₄ (MW = 912.27 g-mol ^"1 ): C 34.23; H 4.09; N 4.61 ; S 14.06. Found: C 34.18; H 4.15; N 4.68; S 14.55

¹ H-NMR (DMSO-d6, 300.13 MHz): δ (ppm) = 1 .30 (6H, m); 2.10, 2.1 1 , 2.13, 2.17 (12H, s); 2.24- 2.52 (4H, m); 3.78-3.88 (2H); 3.78 (4H, m); 3.90 (1 H, m); 4.12-4.20 (1 H, ddd); 4.29-4.40 (1 H, ddd); 4.48-4.51 (1 H, ddd); 4.90 (1 H, t); 5.18 (1 H, t); 5.26 (1 H, t); 5.42 (1 H, t); 6.50 (1 H, m).

Medium FT-IR (KBr): v (cm ¹ ) = 1745 (v, C=0); 1540 (v, C=0); 1645 (v _a , N-CSS)

ESI-MS m/z, found (M ⁺ ): 876.13

EVALUATION OF THE BIOLOGICAL ACTIVITY

Antitumor activity in vitro

The human tumor cell lines MeWo (malignant melanoma) and LoVo (colon adenocarcinoma) were cultured in RPMI-1640 and Hams-F12 medium, respectively. The cells (8 x 10 ³ / mL) were seeded in 96-well plates in the growth medium previously mentioned (100 μΙ_) and then incubated at 37 °C in a controlled atmosphere of carbon dioxide. After 24 hours, the cell culture medium was removed and replaced with fresh one containing the tested compound, previously dissolved in DMSO (0.1 % v/v, freshly prepared solution mantained in the dark), or saline solution, at various concentrations. A total of four independent experiments were conducted and, after 24 hours of treatment, the medium was aspirated, and each well was treated with 100 μΙ_ of a MTT (Methylthiazolyldiphenyl tetrazolium bromide) solution (1 mg/mL in PBS) and the plate was incubated at 37 °C for 4 hours. The MTT solution was then removed and 100 μΙ_ of DMSO were added to each well. The plate was shaked for 10 minutes and then analyzed by spectrophotometry (560 nm). The cytotoxic activity of each compound was evaluated as a percentage of vital cells in the treated sample compared to the cells treated with the vehicle only (control). From the obtained dose-response curves, the IC ₅₀ values for each compound were calculated (i.e. the concentration expressed in μΜ, which inhibited 50% growth in tumor cells compared to the control).

All the above mentioned culture media and the human tumor cell lines can be easily purchased on the market. By way of example, but not limitation of the present invention, the following table collects the IC ₅₀ data of some compounds of the first and second embodiments, the corresponding dithiocarbamato ligands (DTC) and metal precursors. MeWo LoVo HeLa HCT116 HepG2/CTR HepG2/SB3 Α549 Jurkat CH2335

Compound

(μΜ) (μΜ)

2.73 ± 8.89 ± 4.4 ±

[AuCI ₂ (PipeDTC)]

0.09 0.07 0.2

8.07 ± 5.36 ± 2.7 ±

[AuBr ₂ (PipeDTC)]

0.06 0.03 0.2

9.3 ± 1.3 ±

[Aul ₂ (PipeDTC)] 6.4 ± 0.2

0.8 0.2

4.52 ±

[AuCI ₂ (ProOMeDTC)] 6.5 ± 0.6

0.06

4.5 ±

[AuBr ₂ (ProOiBuDTC)] 4.1 ± 0.3

0.6

1.03 0.7 ± 2.97 ± 0.07 2.8 ± 0.1 2.52 0.4± 0.82 ±

1.97 ± 1.8 ±

[Cu(ProOMeDTC) ₂ ] + 0.1 ± 0.3 0.1 0.09

0.07 0.2

0.03

5.6 ±

[Cu(ProOiBuDTC) ₂ ] 4.8 ± 0.3

0.6

1.2 ± 1.8 ±

[Cu(PipeDTC) ₂ ] 0.8 ± 0.3

0.5 0.1

7.7 ±

[Cu(MorfDTC) ₂ ] 5.8 ± 0.2

0.3

1.69 ±

[Cu(PirrDTC) ₂ ] 2.3 ± 0.2

0.04

7.16 ± 5.2 ± 6.24 ±

[Au(PipeDTC)] ₂ CI

0.05 0.3 0.05

5.7 ±

[Au(ProOfBuDTC)] ₂ Br 4.8 ± 0.6

0.6

[AuCI ₂ GalactoseMAE- 6.31 ± 5.3 ±

DTC] 0.07 0.3

[AuBr ₂ Mannose- 8.55 ± 6.6 ±

SarcosineDTC] 0.06 0.5

[Au(Glucosamine- 4.25 ± 7.8 ±

ProDTC) ₂ ]N0 ₃ 0.04 0.5

> 15

KPipeDTC > 15 μΜ

μΜ

> 15

KMorphDTC > 15 μΜ

μΜ

> 15

Na-ProOMeDTC > 15 μΜ

μΜ

> 15

Na-ProOtBuDTC > 15 μΜ

μΜ

K-Glucosamine-ProDTC > 15 μΜ > 15 MeWo LoVo HeLa HCT116 HepG2/CTR HepG2/SB3 Α549 Jurkat CH2335

Compound

(μΜ) (μΜ)

μΜ

> 15

KAuBr ₄ ^■ 2H ₂ 0 > 15 μΜ

μΜ

> 15

CuCI ₂ - 2H ₂ 0 > 15 μΜ

μΜ

1.6 ±

[AuBrCN(PipeDTC)]

0.4

[Cu"(DTC-P-D- 2.7 ±

glucosideMAE)2] 0.4

10.2 ±

Cisplatin 48 ± 2 56 ± 2

0.6

Table 1: In vitro cytotoxic activity (IC _50, expressed in μΜ) of some compounds and DTC ligands against the h uman tumor cell lines MeWo (malignant melanoma) and LoVo (colon adenocarcinoma) after 24 hours of treatment; against the human tumor cell lines: cervix adenocarcinoma (HeLa), colon neoplasia (HCT116), HepG2 : epithelial cells of human liver hepatoma and its more aggressive cou nterpart HepG2/SB3, overexpressing the anti-apoptotic protein SerpinB3; NSC lung carcinoma (A-549); acute T cell leukemia (Jurkat); triple negative breast cancer (crl2335) after 72 hours of treatment. The inorganic reference- drug cisplatin (Sigma-Aldrich) was tested under the same experimental conditions . IC ₅₀ : concentration expressed in μΜ able to inhibit the 50% of the cancer cell growth compared to the control (cells treated with the vehicle). The data represent the mean ± SD of at least four independent experiments.

From the exemplary and non-limiting data shown in Table 1 , it is clear that the inventors have demonstrated that metal precursors alone do not induce any significant antitumor activity. In fact, they show an IC ₅₀ value > 15 μΜ. Similarly, the dithiocarbamato ligands (DTC) alone do not possess remarkable cytotoxic activity. Conversely, the coordination compounds obtained from such precursors, in which the metal is covalently bound to specific DTC ligands, are characterized by a remarkable cytotoxic activity, ranging from 0.4 to 10 μΜ.

Thus, through the present invention, the inventors have shown that such antitumor activity is due to the combination, in a single compound, of a properly-designed DTC ligand with a metal center endowed with specific chemical (oxidation state, reduction potential, geometry coordination, kinetic and thermodynamic properties) and biochemical properties.

It will be apparent to the skilled in the art that a further important object of the present invention has been achieved.

From the data shown in Table 1 , it is also clear that the present inventors have obtained a number of coordination compounds according to the present invention which exhibit higher anti- tumor activity than the reference drug cisplatin. Indeed, as it is well known, the greater the antiproliferative activity, the lower the IC50 value for a specific compound. In this way, another important aim of the present invention has been achieved.

Acute toxicity test in mouse model

Some compounds were tested in vivo to evaluate the acute toxicity by intravenous administration of a single dose to male mice (provided by Charles River Laboratory Italy, Calco, Lecco; 6-week-old mice). This administration route has been chosen because it presents a reduced barrier to substance absorption, provides a more stringent toxicity measure compared to other in vivo assays and it is a typical route of administration in humans. The species/strain mouse/CD-1® was chosen because many regulatory authorities accept and indicate that preclinical acute toxicity tests are performed with this species/strain, in light of the large amount of related bibliography. The administered dose (10 mg/kg) was selected based on the dosages clinically used on humans {e.g., 2 mg/kg) in order to highlight potential signs of toxicity.

The tested compounds are: [Cu(tetra-0-Acetyl-glucopyranosylamidoProDTC) ₂ ], [AuBr ₂ (tetra-0- Acetyl-glucopyranosylamidoProDTC)] and [Au(PipeDTC)(tetra-0-Acetyl-glucopyranosylamido ProDTC)]CI. The chosen vehicle is DMSO-EtOH-RL 50:10:40 % v/v in which RL stands for Ringer lactate (Eurospital ^® ). In the case of the third compound, a physiological solution was chosen as a vehicle. Each experimental group consisted of 6 mice + 4 control animals (vehicle- treated only).

Table 2. Body weights of the treated and non-treated (control) mice. Each dose was prepared by dissolving a calculated amount of compound in DMSO; this volume was subsequently diluted with ethanol and Ringer lactate (RL) to obtain the final desired concentration. The administration of the antitumor compound under study was performed by intravenous injection into the caudal artery of each mouse. Each treated animal received an accurate injected volume of 100 μΙ_, containing the amount of test substance as described above, that is the equivalent of 10 mg/kg. All animals were treated with a single dose at T ₀ after detecting the body weight of each mouse. Clinical observations were recorded at the time of injection, during the first hour and then in the following days for total 7 experimental days, the same for the body weight.

At the end of the study period, animals were sacrificed by C0 ₂ asphyxiation. All animals were subjected to autopsy examination including the opening of the cranial, thoracic and abdominal cavities. All animals survived until the end of the study, and during the post-treatment period they showed no sign of toxicity. The macroscopic necroscopy did not reveal any evident sign of toxicity on the examined organs: brain, lungs, spleen, testes, heart, liver and kidneys.

Table 3. Clinical and behavioral observations during the experimental study.

Surprisingly, the compound [Au(PipeDTC)(tetra-0-Acetyl-glucopyranosylamido ProDTC)]CI is soluble in saline solution in spite of the highly hydrophobic nature of the involved dithiocarbamato ligands. This new and inventive result facilitates the development of this class of compounds for pharmaceutical applications in oncology.

PREPARATION OF SUPRAMOLECULAR AGGREGATES ENCAPSULANTING ANTICANCER COORDINATION COMPOUNDS

It is another object of the present invention a process for encapsulating in supramolecular aggregates the coordination compounds according to this invention, whose features are set forth in the enclosed independent claim. Particularly, in the third and fourth preferred embodiment of this invention, the coordination compounds having the general formula 1(a) and 1(b) are encapsulated in supramolecular aggregates.

By way of example, but not limitation, advantageous supramolecular systems encapsulating the active compound can be micelles, vesicles (liposomes), cyclodextrins, dendrimers, organic polymeric nanoparticles, for instance derived from proteins or peptides, and inorganic nanoparticles {e.g., silica, zirconia, titanium dioxide).

Said supramolecular architectures can be in turn produced with different polymers, natural and synthetic, as well as with proteins or other organic molecules, such as chitosan, polyethylene glycol (PEG), mPEG acid, poly(lactic-co-glycolic acid) (PLGA), Pluronic ^® , cholesterol, derivatives of phosphatidylcholine and phosphatidylethanolamine, Cremophor ^® , pullulan, hyaluronic acid, ferritin, human serum albumin (HSA), heparin, dextran, polyaminoacids (e.g., a- poly-L-glutamic acid) and their derivatives {e.g., PHEA, PHEG), polyglycerol, polyacrylamide, polyvinylpyrrolidone, poly(2-oxazoline) and their derivatives. Moreover, even combinations of these polymers or molecules, such as PEG-PLGA or PEG Pluronic ^® , may be used for the construction of appropriate supramolecular architectures, usable as nanocarriers for the coordination compounds according to the present invention.

In addition, block copolymers, such as those with the A-B-A or A-B architecture, can be advantageously used to prepare supramolecular systems suitable for the delivery of the coordination compounds herein disclosed. In other words, said building blocks, which can be equal or different each other, can be intended both as the monomer {e.g., ethylene oxide) of a polymer such as PEG or PF127, or of an inorganic nanostructure {e.g., Ti0 ₂ ), and the same polymer inside aggregates, for instance micelles.

The terms "supramolecular aggregates", "macromolecules", nanostructures encompasses also for example micelles, liposomes, protein- and peptide-based aggregates and carriers consisting of cyclodextrins or dendrimers.

Moreover, as an example, biocompatible polymers and oligomers, natural or synthetic, identical or different {e.g., phospholipids, pullulan, PEG, PF127, cholesterol) can form micelles or liposomes, in order to modulate the final properties of the composition and therefore of the final formulation. These polymers, identical or different, are the constituent units that aggregate during the formation of the supramolecular system. One of them or all of these polymers can be conveniently functionalized with carbohydrates (by using the functional groups exploitable for this purpose), and in an independent manner, with yields up to 100%. This/these polymer(s) can then be diluted with the same or other polymers to achieve, for example, a micelle or a liposome with a water-exposed surface having a variable percentage of functionalization, ranging from 1 to 50% mol/mol .

Concerning the drug loading, the range 10 ^"5 ÷10 ^"10 mol of compound/mg of formulation can be achieved when preparing compositions of said coordination compound. Furthermore, said compound can be encapsulated in the hydrophobic core of a micelle, or in the hydrophilic counterpart of a liposome, or in their lipidic/polymeric layer. Such supramolecular architectures can in turn be made with different polymers, natural and synthetic, as well as with proteins or other organic molecules, such as chitosan and polyethylene glycol. The nanocarrier (e.g., liposome, micelle) can be conveniently covered with a hydrophilic and biocompatible coating in order to improve the pharmacokinetic profile of the "naked" supramolecular aggregate itself. In other words, by exploiting the so-called "stealth effect", to date known for polymers such as PEG and poly-amino acids, the surface of the supramolecular aggregate is hidden from blood components, including the opsonin proteins, which are responsible for the recognition and attack of the nanocarriers by phagocytes (monocytes, macrophages). This masking strategy allows the supramolecular systems to sidestep the natural processes of biotransformation/elimination of exogenous constituent entities or substances. Moreover, it determines an increased bioavailability and, hence, a prolonged circulation time of the compound loaded into the carrier, if compared to supramolecular aggregates incorporating the coordination compounds according to the present invention and non-covered with said hydrophilic and biocompatible coating. The application of the "effect stealth" to the coordination compounds according to the first and the second embodiment of the present invention may also limit or eliminate any problem at the physiological level, such as hemolysis or immunogenicity of the active compound. In addition, the hydrophilic coating of nanocarrier obtained with polymers such as PEG, reduces the self- aggregation of the particles by means of steric stabilization, thus resulting in an immediate impact on the freshly-prepared formulation for the administration at the hospital level and storage.

In an alternative manner, and to achieve the same benefits, the surface of the nanocarrier can be coated, by adsorption or conjugation, with human serum albumin (HSA) in order to conveniently increase the stability, the circulation times, and the biocompatibility of the formulation. This approach "anticipates" indeed the adsorption of HSA present in the blood and, simultaneously, it avoids the absorption of the aforementioned opsonins.

The whole supramolecular aggregate reduces the off-target release of the drug by the so-called EPR effect (Enhanced Permeability and Retention). The EPR effect is based on the anomalous and high permeability of blood vessels in the tumor region, characterized by not-adherent endothelial cell-to-cell junctions, if compared to normal tissue capillaries. Appropriate nanocarrier sizes, ranging from 20 to 100 nm (as reported in the examples of this invention), result in a prolonged circulation of the supramolecular systems in the blood stream, and the consequent selective extravasation into tumor tissues, resulting in a passive targeted therapy, which positively influences the toxicological profile. In addition, the lack of lymphatic drainage of cancerous compartments promotes the selective accumulation of the nanocarriers in the tumor microenvironment.

Advantageously, the functionalization of the nanocarriers with cancer-targeting moieties can also restrict the onset of side effects, thereby improving the chemotherapeutic index in terms of toxicity/activity ratio (active targeting).

In addition, when the nanocarriers are functionalized with carbohydrates as cancer-targeting moieties, these supramolecular or macromolecular systems give the possibility to increase the water-solubility and the stability of the encapsulated compound(s) as well as to improve the bioavailability, and to extend and facilitate the selective release towards cancer cells.

In summary, by means of the encapsulation of one or more coordination compounds according to the present invention, the inventors have advantageously developed two distinct and complementary strategies for the selective delivery of said compounds in the tumor site. This will be clear from the description of some examples reported below by way of example, but not limitation of present invention.

The first cancer-targeting strategy, associated with the third embodiment, is related to the passive targeting mediated by EPR effect described above. On the other hand, the second strategy, presented in the fourth embodiment, takes into account the active targeting via glycoconjugation of the supramolecular nanosystem, thus providing an additional way to achieve a high therapeutic selectivity.

Anyway, the encapsulation allows the loaded compounds to increase their blood circulation times, as well as to improve the chemotherapeutic index of the active compound (ratio between the lethal dose LD ₅₀ and the effective dose ED ₅₀ ), in other words their pharmacokinetic and pharmacodynamic profiles.

In order to engineer the most suitable encapsulation system (e.g., micelle, liposome), the partition coefficient n-octanol/water (P) was evaluated (and expressed in its logarithmic form, logP) for some coordination compounds with general structure l(a) and l(b), below described by way of example, but not limitation of the present invention. It is known that the value P expresses the ratio between the concentration of a compound in n-octanol and the concentration of the same compound in water, at equilibrium. EXAMPLES OF NANOFORMULA TIONS FOR PASSIVE TARGETING

In the third preferred embodiment of the present invention, the coordination compounds having a general Formula l(a) and/or Formula l(b) are encapsulated in supramolecular aggregates, in particular micelles, to achieve a passive targeting mechanism mediated by the EPR effect. Said encapsulated compounds may be those of the second embodiment, and hence conjugated to carbohydrates, or without a cancer-targeting moiety (first embodiment).

For pharmaceutical applications, the ideal size of supramolecular systems ranges from 10 nm to 100 nm. In particular, a fast drainage from the injection site and an effective distribution in vivo are obtained with particles characterized by a hydrodynamic diameter (DH) ranging from 10 to 70 nm. In addition, once reached the target cells, the nanocarriers with DH < 100 nm at the cellular level can be absorbed by an endocytic process. In fact, it is well known that the size of the aggregates can significantly affect the circulation times and the bioavailability of the encapsulated compound.

From the description provided above, by way of example but not limitation, it will be clear that, the inventors have advantageously showed showed the possibility to achieve nanoformulations characterized by different hydrodynamic diameters (DH) with an average value of about 25-30 nm or 80-100 nm, namely belonging to ranges of extreme interest for pharmaceutical applications.

LogP evaluation procedure

By way of example, but not limitation, the procedure to evaluate the partition coefficient n- octanol/water (P) (expressed in its logarithmic form, logP) of some coordination compounds having general structure l(a) and l(b) is here described. It is known that this procedure is fundamental for the choice of the most suitable supramolecular system for a specific type of compound and/or application. Going into detail, the concentration of the compounds in the two immiscible phases has been determined in n-octanol before and after mixing with a defined volume of water. In particular, n-octanol was pre-saturated with deionized water for 24 hours under stirring, then let to equilibrate for 6 h at 25 °C. A defined amount of compound is weighted and dissolved in a determined volume of the organic phase, and then stirred at 25 °C for two hours after the addition of the same volume of deionized water. Subsequently, the mixture is equilibrated for 30 minutes. The concentration of compound in the organic phase before (C ₀ ) and after the separation (Ci) was evaluated by UV-Vis spectrophotometry. The obtained values (Table 4) were used in the calculation of the partition coefficient n-octanol/water (P) according to the formula logP= log[d / (C0 ₀ - C ].

From the results reported in the Table 4, it is clear that the present inventors have engineered coordination compounds according to the present invention with differentiated logP values and capable of covering intervals of interest for the future preclinical and clinical development of pharmaceutical compositions based on the coordination compounds according to the present invention. In fact, molecules with logP <0 are potentially suitable for the intravenous administration, whereas compounds with a value of 0 <logP <3 are suitable for oral administration. In this way, one of the purposes of the present invention has been advantageously achieved. COMPOUND logP st. dev.

[Au(PipeDTC)CI ₂ ] 1 .08 0.04

[Au(PipeDTC)Br ₂ ] 1 .1 0.2

[Au(ProOMeDTC)CI ₂ ] 0.99 0.04

[Au(ProOMeDTC)Br ₂ ] 1 .1 0.1

[Au(ProOtBuDTC)CI ₂ ] 1 .6 0.2

[Au(ProOtBuDTC)Br ₂ ] 1 .69 0.06

[Cu(PipeDTC) ₂ ] 1 .5 0.1

[Cu(ProOMeDTC) ₂ ] 1 .3 0.2

[Cu(ProOtBuDTC) ₂ ] 1 .6 0.3

[Au(PipeDTC) ₂ ]CI -1 .05 0.05

[Au(PipeDTC) ₂ ]Br -1 .05 0.03

[Au(PipeDTC) ₂ ]AuCI ₄ 0.12 0.02

[Au(PipeDTC) ₂ ]AuBr ₂ 0.21 0.06

[AuCI ₂ (galactopyranosideMAE-DTC)] -1 .1 0.2

[Cu(2,3,4,6-tetra-0-acetyl- + 1 .2 0.3

glucopyranosylamido-L-Proline DTC]

[Cu"(DTC-p-D-glucosideMAE)2] -1 .2 0.1

[Au"'(DTC^-D-glucosideMAE) ₂ ]CI -1 .9 0.1

Table 4. Experimental values of log P = log[C ₁ /(C ₀ — C^] of some coordination compounds, presented according their structures in the different embodiments of the present invention.

Some examples of supramolecular systems that the present inventors have developed based on the logP value so determined are reported below.

Considering the logP values reported in Table 4 and the IC ₅₀ data recorded in vitro (Table 1 , with reference to the first and second embodiments), it appears evident to the skilled in the art that the here claimed coordination compounds are characterized by different LiPE values (LiPE= - loglC ₅₀ - logP), for some being within the range 4 to 6, considered ideal for the purposes of the so-called "druglikeness". (Hopkins, "Nature reviews drug discovery", vol. 13, 2014; Leeson and Springthorpe "Nature reviews drug discovery", vol. 6, 2007).

Encapsulation in vesicles

Without loss of generality of the present invention, a procedure for the loading of some compounds according to the invention having logP <0 (Examples 13 and 1 1 ) in nanolipidic systems, namely in vesicles also known as liposomes, is described below. Among the nanolipidic systems, the present inventors have advantageously prepared 1 ,2-dipalmitoyl-sn- glycero-3-phosphocholine vesicles (DPPCs), endowed with high biocompatibility, biodegradability, low toxicity and self-assembly capability to form vesicle structures (CMC = 0.46 nM). The liposomes were prepared by dissolving DPPC (4 mg) and the compounds of Examples 1 1 and 1 3 (0.4 mg) in chloroform. The solvent was slowly evaporated by nitrogen stream, thus obtaining thin homogeneous DPPC / [Au(ProOtBuDTC) ₂ ]Br and DPPC / [Au(PipeDTC) ₂ ]CI films, which were further dried under reduced pressure. The subsequent hydration took place at temperatures above the critical temperature of the phospholipids (about 50 °C) by adding 1 mL of saline solution (NaCl _aq 0.9% w/v). The obtained suspension was then stirred for 30 min and then subjected to 5 fast freezing/thawing cycles in liquid nitrogen and water bath at 37 °C to obtain large polydispersed unilamellar vesicles. The latter were then subjected to an extrusion process through a porous polycarbonate membrane having an average pore diameter of 1 00 nm, in order to isolate, advantageously, small unilamellar vesicles. The liposomes thus obtained were subjected to a dialysis process for two hours against saline to eliminate traces of non-encapsulated coordination compound and free phospholipid. Finally, after extrusion the systems were analyzed using Dynamic Light Scattering (DLS) to evaluate their hydrodynamic diameter.

Hydrodynamic Diffusion

[Au] Diameter ± st. P.I. ± SD Coefficient

dev. (nm) [mV]x10- ¹² (x10 ^_4 M)

DPPC control 83 ± 20 0.6 ± 0.2 5.6 ± 0.4 —

DPPC/[Au(ProOtBuDTC) ₂ ]Br 90 ± 1 7 0.6 ± 0.2 5.2 ± 0.2 4.46 ± 0.2

DPPC/[Au(PipeDTC) ₂ ]CI 89 ± 1 8 0.4 ± 0.2 4.8 ± 0.3 4.22 ± 0.3

Table 5. Structural and compositional parameters of vesicular systems determined by DLS and ICP-AES measurements.

It is clear that by means of the procedure described above, it is indeed possible to reproducibly load two Au(l l l) compounds into vesicles, realizing a concentration of about 430 μΜ. Such vesicles are characterized by a D _H of about 80 nm when they are empty while they reach a hydrodynamic diameter of about 90 nm after loading. The stability of the coordination compounds was determined by UV-Vis spectrophotometry in saline (NaCl _aq 0.9% w/v) at a concentration of about 50 μΜ (at 37 °C for 72 h).

With reference to the enclosed Figure 3, here reported merely as an example, the spectra recorded over time for the compound [Au(ProOtBuDTC) ₂ ]Br, encapsulated in DPPC vesicles, highlight the stability of the compound and the hyperchromic effect of the absorption bands is ascribable to increased light diffusion due to the formation of larger-size aggregates in solution. This was then confirmed by sample DLS measurements after 72 hours, recording a D _H that varies from 90 ± 17 to 1 799 ± 480 nm.

Although the present example refers to liposomes of DPPC derivatives, with trivial modifications for the skilled in the art, the procedure is practically analogous for other classes of amphiphilic polymers useful for the production of vesicles. The present inventors have also identified some alternative processes for the preparation of liposomes encapsulating hydrophilic coordination compounds according to the invention, in which an aqueous solution of the compound is used instead of an organic solvent. By way of example and not limitation of the present invention, a first procedure involves: the dissolution of the biocompatible polymer or more than one in an organic solvent such as chloroform; removal of solvent; hydration of the lipid film with an aqueous solution and treatment of the suspension obtained by sonication; extrusion through membranes having a certain cut-off; dialysis against aqueous solution such as saline or phosphate buffer; incubation of the compound with the solution in a T> T _c water bath under continuous stirring for at least 20 minutes; lyophilization (in the presence of cryoprotector); hydration and extrusion. The cryoprotector may be, for example, mannitol or lactose or sucrose or trealose or glucose or maltose, ethanol or a combination thereof.

Alternatively, a second process involves: dissolution of the biocompatible polymer in water or glycerol/ethanol mixture or alternatively the dissolution of several polymers in an organic solvent such as chloroform, followed by removal of the solvent; addition of the aqueous solution of the compound; agitation of the obtained mixture and multiple freeze/thaw cycles in liquid nitrogen and water bath at 37 °C; extrusion.

Finally, a third process involves the dissolution of the biocompatible polymer (or biocompatible polymers) in organic solvent, for example chloroform; the addition of the aqueous solution of the compound, forming an emulsion; agitation of the obtained mixture and evaporation of the solvent medium; the addition of a buffer and purification via extrusion.

Encapsulation in micelles

By way of example and not limitation, a procedure for the encapsulation (loading) in micelles of some compounds according to the invention having logP > 0 is described below. Without loss of generality of the present invention, the inventors have developed a loading system using Pluronic® F127 (indicated also as "PF127") as a polymeric substrate. However, this procedure is basically similar for any amphiphilic polymer (e.g., mPEG), with trivial changes to the skilled person. The encapsulation of the complexes having Formula l(a) and/or Formula l(b) in PF127 micelles was obtained via a process comprising the following steps, described herein as non- limitative examples of the present invention: 1 ) Co-dissolution of the compound to be loaded and the polymer in the desired stoichiometric ratio (e.g., 0.5 mg and 500 mg, respectively) in an organic solvent, preferably chloroform; 2) Evaporation of the organic solvent, preferably under reduced pressure, followed by drying of the obtained powder, preferably under vacuum; 3) Hydration of the powder by addition of deionized water; 4) in order to remove the non- encapsulated compound, bacteria and other impurities, purification for instance by filtration with a membrane with a 0.20 μηι cut-off; 5) Freezing of the sample in a dry ice/acetone cooling bath at -78 °C and cryoesiccation to remove the residues of the aqueous solvent, thus obtaining a storable ready-to-use formulation. The amount of the encapsulated coordination compound was assessed by UV-Vis analysis, after dilution in DCM of a defined amount of lyophilized micellar formulation. In particular, the concentration of the compound was defined using the Lambert- Beer law, after experimental determination of the molar extinction coefficient ε in DCM (based on the "matrix effect", in the presence of the same polymer used for the preparation of micelles) for some absorption bands. The obtained results are reported in the following Table.

Table 6. Amount of encapsulated compound in terms of drug loading (mol of encapsulated compound per mg of formulation) and Encapsulation Ratio (ER), i.e., the percentage amount of encapsulated compound compared to the amou nt of nominally-loaded compound.

Advantageously, the encapsulation in micelles of the metal-based compounds according to the present invention increases their stability in physiological media and make them water-soluble for at least 72 hours. In fact, with reference to the enclosed Figure 4, here illustrated as a non- limitative example of the present invention, the collected electronic spectra surprisingly show no significant change over time for the considered formulations (if compared to the not encapsulated compound) once dissolved in a physiological environment consisting of phosphate buffer/cell culture medium 9: 1 v/v, and phosphate buffer/human serum 95: 5 v/v. Hence, it is evident that the present inventors have obtained compositions comprising the coordination compounds according to the present invention, characterized by a complete solubility and stability in physiological media compared to the corresponding non-encapsulated compounds, thus reaching a further goal of the present invention.

polydispersion index.

It is clear from the results presented in Table that micellar systems with hydrodynamic diameters of about 25 nm are particularly advantageous pharmaceutical applications, in particular in the oncological field for the intravenous administration, thus exploiting to the best the EPR effect. As already mentioned, the use of PF127 does not limit the scope of the present invention, since other polymeric substrates can be conveniently used.

Cyclodextrin encapsulation

By way of example and not limitation of the present invention, a procedure for loading cyclodextrins with a Cu(ll) coordination compound having logP > 0 is described below. The present inventors hereby provide, for example, a 2-hydroxypropyl^-cyclodextrin (ΗΡ-β-CD) formulation, a cyclic oligomer consisting of seven a-(1 ,4)-D-(+)-glucopyranoside units with a degree of molar substitution for hydroxypropyl groups of 0.8. The ΗΡ-β-CD cyclodextrins are a nanocarrier with high biocompatibility and biodegradability and are already used in clinics in formulations administered parenterally.

The samples are prepared by dissolving the cyclodextrin and the coordination compound [Cu(PipeDTC) ₂ ] (1 :1 molar ratio) in DMSO and keeping the system under stirring for 15 hours. The organic solvent is then removed under reduced pressure conditions and the residue dissolved in water, centrifuged and the filtered liquid phase (0.22 μηι filter) is lyophilized to obtain a ready-to-use formulation.

As shown in Figure 5, the UV-Vis curves collected over time do not show significant spectral variations, demonstrating the high stability of the formulations herein presented. The supramolecular system here presented represents an effective carrier for pharmaceutical applications since the corresponding K _B compound/cyclodextrin was approximately 558 M ^~1 . Through the examples described above, by way of example and not limitation, the present inventors have surprisingly demonstrated the ability to encapsulate the coordination compounds of general formula l(a) and l(b) in macromolecules or in a supramolecular system, overcoming evident limitations in the state of the art in a non-trivial way. In fact, the encapsulation techniques of metal-based compounds are still at the forefront, due to the intrinsic reactivity of inorganic molecules.

In this way, the encapsulation allows said compounds to be protected from biotransformation and to avoid interactions/reactions with biomolecules or cells present in the blood stream. In addition, the encapsulation allows to increase the stability as well as the solubility of the hydrophobic compounds in the physiological media as demonstrated by the data herein presented.

EXAMPLES OF NANOFORMULA TIONS FOR THE ACTIVE TARGETING

In a fourth preferred embodiment, illustrated here as non-limitative example of the present invention, the coordination compounds described above, having general Formula l(a) and l(b), are advantageously encapsulated in supramolecular aggregates and functionalized with carbohydrates. Therefore, they are directed to the tumor site according to an active-targeting approach which is paralleled with (hence boosting it) the mechanism of passive targeting of the previous embodiment In other words, in the fourth embodiment the whole supramolecular aggregate acts as a cancer-targeting carrier, conveniently exploiting the Warburg effect, to further improve the therapeutic selectivity. In particular, the inventors aim to implement a mechanism wherein a coordination compound according to the invention is absorbed by the cell by endocytosis along with the whole supramolecular aggregate; alternatively, said compound can be released from the nanocarrier in the extracellular matrix, and consequently diffusing inside the cell if hydrophobic enough, or entering the cell through alternative mechanisms of uptake, or also triggering its antitumor activity at the cell membrane level. In the latter case, compounds of the first embodiment, which by their chemical nature inherently exhibit affinity for the cell membrane, or compounds of the second embodiment that can exploit the presence of a cancer-targeting moiety T in the selective recognition by carbohydrate transporters (e.g., GLUT1 ), are advantageously used, alternately or in combination between them. Such compounds are hence encapsulated exploiting the procedures disclosed by the inventors with reference to the third embodiment so to form a supramolecular aggregate with a variable degree of functionalization, for example ranging from 1 to 50%. As non-limitative examples, convenient supramolecular aggregates can be micelles, vesicles (liposomes), cyclodextrins, dendrimers, organic polymeric nanoparticles, for instance of protein or peptide nature, and inorganic nanoparticles {e.g., silica, zirconia, titania). Carbohydrates can be monosaccharides, polysaccharides, pentoses, hexoses, aldoses, ketoses. Such supramolecular aggregates may have a mixed structure, for example being made up of pullulan and PF127, or PLA and PEG.

FUNCTIONALIZA TION OF BIOCOMPA TIBLE POL YMERS

With reference to the scheme reported below, the following non-limitative examples illustrate some synthesis that demonstrate the possibility to functionalize with different chemical groups the hydrophilic terminal end of biocompatible polymers, such as the polyethylene glycol (PEG) and the family of polymers known under the trade name Pluronic ^® F127. These functionalized derivatives are subsequently bio-conjugated with specific carbohydrates, in turn suitably functionalized, advantageously exploiting known synthetic strategies.

The biopolymer so functionalized with a carbohydrate, after dilution with a non-functionalized biopolymer (equal or different), is used to form a supramolecular aggregate with a degree of functionalization, ranging from 1 % to 50% mol/mol. As non-limitative examples of the present invention, the schemes and the descriptions of some reactions carried out starting from the methoxy polyethylene glycol (mPEG) 5000 polymer are reported below. Synthesis of mPEG5000-Ts

To a solution of mPEG5000 in dry CH2CI2 dry at 0 °C, 0.5 eq. of 4-dimethylaminopyridine (DMAP) and 10 eq. of triethylamine (Et ₃ N) were added. Then, after the addition of 10 eq. of p- toluensulfonyl chloride (TsCI) the reaction was stirred for 24 hours. The mixture was washed with HCI 0.1 M and an aqueous solution saturated with NaCI ("brine"). After treatment of the organic phase with diethyl ether, a white product precipitated. The functionalization degree was equal to 100%, considering the integration values of NMR signals corresponding to the aromatic protons of the tosylate and the methyl protons of the terminal methoxy group of mPEG5000 polymer. IR: v (cm ¹ ) = 2885, 1467, 1344, 1 1 13, 1060, 842, 664.

Synthesis of mPEG5000 -Phta

The polymer mPEG5000-Ts was refluxed in dry DMF for 5 hours in presence of 20 eq. of phthalimide potassium salt (Phta K). Successively, after filtration of byproducts and precipitation with diethyl ether, a light yellow solid was isolated. The functionalization degree was equal to 100%, in light of the integration values of the NMR signals corresponding to the aromatic protons of the phthalimide and methyl protons of the terminal methoxy group of mPEG5000 polymer. IR: v (cm ¹ ) = 2885, 1716, 1467, 1344, 1 1 14, 1060, 842, 724, 690.

Synthesis of mPEG5000-NH ₂

This Gabriel-like synthesis of amines was carried out according to a modified literature procedure. 50 eq. of hydrazine (NH ₂ NH ₂ ) were added to a solution of mPEG5000-Phta in EtOH at reflux. After 16 hours the crude product was precipitated with diethyl ether, leading to a white solid. The functionalization degree (-NH ₂ terminal group) is equal to 45%, based on the integration values of the NMR signals corresponding to the a-methylene protons with respect to the amino group (CH ₂ -NH ₂ ) and methyl protons of the terminal methoxy group of mPEG5000 polymer. IR: v (cm ¹ ) = 2884, 1467, 1344, 1 1 13, 1060, 842.

Synthesis of mPEG5000-SC

This reaction allows the conversion of the terminal hydroxyl group to a carbonate which is very reactive towards nucleophiles due to the presence of a succinimido leaving group. The reaction was performed in a Schlenk line. Briefly, mPEG5000 was dissolved in dry 1 ,4-dioxane and was added to a mixture of DMAP (6 eq) and Λ/,Λ/'-disuccinimmidil carbonate (DSC) in dry acetone. After 6 hours, the by-products were filtered and the solution volume was reduced to precipitate a white solid after the addition of diethyl ether. The functionalization degree is 100%, considering the integration values of NMR signals corresponding to the methylene protons of the succinimido group and the methyl protons of the terminal methoxy group of mPEG5000 polymer.

Synthesis of mPEG5000-GluOAc

The bio-conjugated mPEG5000-GluOAc was obtained via nucleophilic attack of the terminal hydroxyl group of the polymer to the anomeric C1 carbon of 1 ,2,3,4,6-penta-0-acetyl^- glucopyranose in the presence of BF ₃ Et ₂ 0. In particular, 3 eq. of BF ₃ Et ₂ 0 were added to a mixture of mPEG5000 and 1 ,2,3,4,6-penta-0-acetyl^-D-glucopyranose (3 eq.) in dry CH ₂ CI ₂ dry at 0 °C, and the mixture was stirred for 48 hours. Then it was concentrated under vacuum and precipitated with diethyl ether, leading to the isolation of a white solid. The functionalization degree was equal to 20%, based on the integration values of NMR signals corresponding to the methyl protons of the acetate and the methyl protons of terminal methoxy group of mPEG5000 polymer. IR: v (cm ¹ ) = 2887, 1759, 1467, 1344, 1 1 1 1 , 1060, 842.

Synthesis of mPEG5000-GluOH

The polymer mPEG5000 functionalized with β-D-glucopyranose was obtained from the product of the previous step (mPEG5000-GluOAc) via deprotection of the acetyl groups under basic conditions (NaOMe in dry methanol) under stirring for 15 hours. Then, the reaction mixture was neutralized with an acid resin (e.g., Amberlite ^® H+ form) for one hour under stirring. After the filtration of the resin, the product was precipitated with diethyl ether and dried under vacuum. IR: v (cm ¹ ) = 3453, 2886, 1759, 1467, 1344, 1 1 12, 1060, 842.

The obtained polymer results 20% functionalized as O-glycoside (in C1 position), and can be used as such to encapsulate the coordination compounds, thus forming micelles or aggregates. Alternatively, it may be used in diluted form in combination with other biocompatible polymers to obtain cancer-targeting nanoformulations such as, without loss of generality: mixed micelles, liposomes, HSA nanoparticles. The latter, covered with a carbohydrate-functionalized mPEG, exhibit a "stealth effect", which is known to be associated with a decreased opsonization.

Similarly, the reaction scheme related to the PF127 polymer herein illiustrated as non-limitative example of the present invention is reported.

Synthesis of PF127-CHO

Accordin to the following reaction scheme:

PF127-CHO

80% The oxidation of the terminal hydroxyl groups of the PF127 polymer to aldehyde was performed using the Parikh-Doering oxidation method. Briefly, a DMSO solution of 3 eq. of Py S0 ₃ (Py = pyridine) was reacted with a DMSO solution of PF127 (1 eq.) and Et ₃ N (6 eq.) at 20 °C. After 24 hours, the mixture was diluted in CH2CI2 and washed with an aqueous solution saturated with NaCI ("brine"). The organic phase was then concentrated and treated with diethyl ether, thus isolating a white solid. The degree of oxidation to aldehyde (evaluated via ¹ H-NMR in CD ₂ CI ₂ ) was equal to 80%, considering the integration values of NMR signals corresponding to the aldehyde proton and the methyl protons of the central PPO unit of the PF127 polymer.

IR: v (cm ¹ ) = 2884, 1630, 1467, 1344, 1 1 15, 1061 , 842.

Synthesis of PF127-GlnOAc

According to the following reaction scheme:

PF127-CHO

PF127-GlnOAc has been obtained by reductive amination between the PF127-CHO derivative described above and 1 ,3,4,6-tetra-0-acetyl-2-amino-2-deoxy^-D-glucopyranose HCI. In particular, the first step involves the nucleophilic attack of the glucosamine, reaction carried out in acetonitrile for 2 hours at room temperature. Subsequently, the reduction of the imine to amine was obtained by the addition of sodium cyanoborohydride. The reaction occurs in acetonitrile for 30 minutes at room temperature with a total stoichiometric ratio 1 :1 :3 between PF127-CHO, glucosamine- HCI and NaCNBH ₃ , respectively. Subsequently the solvent was removed under reduced pressure and the residue is taken up in DCM, washed in a separatory funnel with "brine". The organic phase is anhydrified and the product precipitated with diethyl ether. The degree of functionalization (assessed via 1 H-NMR in CD ₂ CI ₂ ) was equal to 44%, considering the integration values of NMR signals corresponding to the acetate protons of glucosamine and the methyl protons of the central PPO unit of the PF127 polymer. ¹ H-NMR (600 MHz, CD ₂ CI ₂ ): δ (ppm) = 1 .10 (t, 241 H, CH3 PF127), 1 .99 (s, 3H, COCH3), 2.03 (s, 3H, COCH3), 2.12 (s, 3H, COCH3). IR: v (cm ¹ ) = 2883, 1757, 1467, 1344, 1 1 14, 1060, 842. Synthesis PF127-GlnOH

The polymer PF127 functionalized with 2-amino-2-deoxy-D-glucose (glucosamine) was obtained from the PF127-GlnOAc of the previous step by deprotection of the acetyl groups under basic conditions (NaMeO in dry methanol) under stirring for 15 h. Subsequently, the mixture was treated with an acid resin (e.g., Amberlite ^® H+ form) for one hour under stirring. After filtration, the product was precipitated with diethyl ether and dried under vacuum.

IR: v (cm ¹ ) = 3432, 2885, 1467, 1344, 1 1 12, 1060, 842.

The obtained polymer results 44% functionalized with glucosamine in C2 position and can be used as such to encapsulate the coordination compounds, forming micelles. Alternatively, it may be used in combination with other biocompatible polymers to obtain cancer-targeting nanoformulations. As a non-limitative example, mixed micelles or supramolecular aggregates can be prepared starting from this derivative, after "dilution" with non-functionalized PF127, or another biocompatible polymer, in order to obtain different degrees of functionalization of the supramolecular aggregate, preferably in the range 2 ÷ 18%.

Through the synthetic schemes described above, formulations wherein coordination compounds according to the invention are encapsulated in micelles functionalized with carbohydrates have been prepared (Table 8). Different formulations (Table 8) consisting in carbohydrate-modified micelles encapsulating coordination compounds according to the present inventions have been prepared via the procedures previously presented.

Table 8. Structural parameters of the micellar systems herein described, determined by DLS analysis.

Surprisingly, all the synthetic procedures allow achieving a degree of functionalization equal or greater than 20%, as verified through ¹ H-NMR analysis in CD ₂ CI ₂ .

Based on the syntheses herein disclosed, it will be apparent to the skilled in the art that he present inventors have overcome relevant issues in the state of the art in a novel and inventive manner. Indeed, although the functionalization of polyether derivatives such as Pluronic ^® F127 and mPEG is widely described in literature, the syntheses herein reported are often difficult to reproduce due to the high molecular weight of the involved surfactants as well as the viscosity of their solutions in organic media {e.g., DCM or THF). Consequently, all the synthetic strategies need to be adapted and optimized in every specific case. In addition, the purification is often troublesome due to the high chemical similarity between the polymeric reagents and their products, characterized by minimal changes (in terms of molecular weight and introduced functional groups) in the molecular structure. Given the complexity of these systems, also the functionalization/bio-conjugation yields are often low (<50%), and the assessment of the degree of functionalization of the products results difficult because of the abovementioned purification problems and the instrument sensitivity.

Although the examples of functionalization herein described are referred to mPEG and PF127, it will be clear to the skilled in the art that the application of the usual synthetic techniques allows the functionalization of other types of biocompatible polymers.

EVALUATION OF THE BIOLOGICAL ACTIVITY

Antitumor activity in vitro

From the description and from the experimental data provided above, the coordination compounds according to the first and second embodiment of the present invention possess a remarkable anticancer activity. Likewise, said compounds loaded into aggregates, according to the third and fourth embodiment, maintain such antitumor capacity, thus achieving a further advantageous object of the present invention. Indeed, by its nature the encapsulation does not alter the anticancer properties of said compounds, independently on the functionalization of the aggregate itself. In other words, these supramolecular aggregates play only the role of nanocarriers, in particular increasing the stability and solubility of said compounds in aqueous medium, and anyway allowing the release of the active compound within the cancer cell or in the extra-cellular matrix, or in general, in the bloodstream.

Therefore, the previously presented in vitro results concerning the antitumor activity of the coordination compounds, can be extended also to the described formulations, with reference to the third and fourth embodiments. By way of example and not limitation, the antitumor activity of IC50 micelles loaded with Cu complexes is presented in the following table.

Table 9 IC50 va l ues (μΜ) for PF127-based formu lations eval uated after a 72-h treatment. Val ues are calcu lated based on the concentration of the encapsu lated copper-DTC com plex. Lyophilized micel les were dissolved in cel l cu ltu re mediu m. Data represent the mea n ± SD of at least th ree independent experiments. THERANOSTIC USE OF THE COORDINATION COMPOUNDS AND THE RELATED COMPOSITIONS AND PHARMACEUTICAL FORMULATIONS

Advantageously, the coordination compounds, the compositions, and the pharmaceutical formulations according to the present invention can be used as "theranostic agents". Therefore not only for the treatment of human or animal diseases, in particular neoplastic diseases, but also for the diagnosis and the patient follow-up.

Within the more general scope of the present invention, such mechanism that combines therapy and diagnosis can be achieved in many ways, properly including one or more contrast agents in a coordination compound, or in a composition comprising at least one of said coordination compound, or also in a pharmaceutical formulation that includes said compound and/or composition.

By way of example, but not limitation of the present invention, referring to the general Formula l(a) or l(b), the contrast agent can be "intrinsic" to the compound, for example when the metal center M is a radionuclide, such as ⁶⁴ Cu o ¹⁹⁸ Au, previously introduced. On the other hand, also the donor atoms X o Y present in Formulae l(a) o l(b) may possess radioactive properties {e.g., ¹³¹ 1, ¹²⁷ l, ¹²⁹ l), as well as T can be 2-deoxy-2-[ ¹⁸ F]-fluoroglucose. Finally, the coordination compound, the unit A, the carbohydrate or glucide T and/or T is paramagnetic or diamagnetic. In addition, the contrast agent can be "exogenous" to the compound, and may be included in the composition that comprises at least one coordination compound according to the present invention, or also in a pharmaceutical formulation, that includes said compound and/or composition. Again, as non-limitative example of the present invention, this category comprises a carrier that encapsulates said compound, such as a up-converting bismuth oxide nanoparticle (e.g. Italian patent 0001419393, in the name of BEP Sri et al.). In this case, the contrast agent is a dual-mode contrast agent that take advantage of the X-ray absorption and the optical emission (through a NIR->NIR or NIR->VIS mechanism) exhibited by the doped bismuth oxide nanoparticles. Other organic and inorganic luminescent systems, such as nanoparticles and compounds, as well as their use in the diagnosis and imaging of biological systems are well known at the state of the art. Therefore, depending on the necessity, the "exogenous" contrast agent may also be a component of the pharmaceutical formulation, for example, a known contrast agent. A "combined" contrast agent can be used and obtained mixing one or more "intrinsic" contrast agents with "exogenous" contrast agents. For example, radionuclides such as ¹³¹ 1, ¹²⁷ l, ¹²⁹ l may be previously introduced as donor atoms X or Y in the Formula l(a) and/or l(b); the coordination compound can be linked to a carrier consisting of a photoactivatable nanoparticle, such as a properly doped bismuth oxide nanoparticle.

Other examples will appear or become evident to the skilled in the art, on the basis of the disclosure herein provided, or through practice of the same, and on the basis of the knowledge at the state of the art in the field of material science, devices and equipment for medical or biomedical imaging and diagnosis. In the various non-limitative examples illustrated herein, with the only aim to show that the coordination compound according to the invention can be advantageously used to obtain a compound or a theranostic agent, it is essential that the contrast agent is detectable by suitable devices or detectors, hence to be usable in association with diagnostic and imaging systems in the medical or biomedical field. In other words, said contrast agent must be able to emit a signal detectable spontaneously, or after interaction with, for instance, irradiation with external particles, or with an external magnetic/electric field.

Contrast agents capable of spontaneously emit a detectable signal are, for example, radionuclides such as ¹¹ C, ¹⁸ F, ⁶⁴ Cu and ¹⁹⁸ Au (in this case the signal is a radiation and/or a particle), or radiopaque materials (the signal here is related to the X-ray absorption spectrum). Other contrast agents emit a signal which is detectable after an external stimulus, which is typically the irradiation with particles and suitable electromagnetic radiations (based on the needs). As an example, this category comprises: luminescent photoactivable contrast agents, such as nanoparticles, dye-molecules or luminophores, capable of emitting IR-VIS radiation as a result of laser irradiation with a suitable wavelength; contrast agents capable of emitting a detectable signal due to the presence of dipoles or magnetic domains within their structure, which interact with an appropriate electromagnetic field; it is also possible to generate radionuclides inside of the compound and/or the composition according to the invention, treating them with particles and electromagnetic radiations with the suitable energy, using known techniques.

It will be evident to those skilled in the art, based on the second and fourth embodiments, described above, by way of example and not limitation, the theranostic applications of the coordination compounds having general Formula I (a) and/or l(b) are very promising in view of the high selectivity and bioavailability, being as above presented, related to the presence of the carbohydrate or glucide T and/or T', that acts as cancer-targeting moieties able to implement a passive and active targeting-mechanism towards the tumor cells.

CONCLUSIONS

In conclusion, it is apparent to those skilled in the art that the present invention fully achieved the intended aim and objects by means of the disclosure provided herein.

The invention thus conceived is susceptible of numerous modifications and variations, without departing from the basic concepts as disclosed herein. Moreover, all the details may be replaced with other technically equivalent elements. Furthermore, the order of the process steps described above is shown by way of example, but not limitation and can be changed according to convenience. The above description and drawings are only illustrative of preferred embodiments which achieve the objects, features and advantages of the present invention, and it is not intended that the present invention be limited thereto. All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. It will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art in view of this specification and which are all considered within the scope of the claimed invention

Although the description and examples above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Therefore, any modification of the present invention which comes within the spirit and scope of the following claims is considered part of the present invention.

In the appended claims, reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more." Where the characteristics and techniques mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example, but not limitation by such reference signs.

Trademarks

Pluronic® is a trademark of BASF AG;

Cremophor ^® is a trademark of BASF AG;

CD-1 ^® is a trademark of di Charles River Laboratories, Inc. Corp.;

Eurospital ^® is a trademark of Eurospital Spa;

Lipoxal ^® is a trademark of Regulon A.E;

Amberlite ^® is a trademark of Santa Cruz Biotechnology Inc.