Field of the invention

The present invention provides novel macrolide compounds capable of stimulating the immune system. The present invention relates to novel compounds for use in medicine, notably in the treatment of viral diseases such as HIV, and in the treatment of chronic inflammatory conditions and in cancers where stimulation of the immune system is beneficial. The compounds may also be used as immune modulating adjuvants in vaccination. The novel macrolides maximize the modulating effects of the immune system while minimizing the therapeutically unwanted direct antibacterial effects. The present invention also provides methods for preparing compounds of the invention and for use of the compounds in medicine.

Background of the invention

Macrolides, such as erythromycin and azithromycin, have been used for years in the treatment of bacterial infections. Erythromycin is a polyketide natural product macrolide produced by fermentation of the actinomycete Saccharopolyspora erythraea. Azithromycin is a semisynthetic azalide derivative of erythromycin. Many references exist describing the antibacterial activity of macrolides, such as erythromycin. This antibacterial mechanism is achieved through molecule binding to the P-site on the bacterial 50S bacterial ribosome, thus interfering with the tRNA binding.

Many references describe generation of analogues of erythromycin via semisynthesis and biosynthetic engineering. In particular, methods have been described for semisynthetic removal of the glycosyl groups on erythromycin, desosamine/cladinose and my- carose. Further methods have been described for biotransformation to add alternative glycosyl groups to the erythromycin aglycone (eg see Gaisser et al. 2000, Schell et al. 2008 and WO 2001/079520). The main focus of this published work, however, has been to generate antibacterial erythromycin analogues. Description of the invention

Immune stimulating activity from macrolides that lack antibacterial activity has previously not been reported. Surprisingly, we found that compounds of the invention, such as compound 1 (Figure 8) had a potent immune stimulating effect on several cell types of the immune system. After 24-48h of in vitro stimulation of peripheral blood mononu- clear cells (PBMC) with 1 μΜ compound 1 , the activation marker CD69 was upregulated on CD4 ⁺ T cells and B cells (Figure 2). We also observed upregulation of the MHC class I molecule (H LA-ABC) on T- and B-cells (Figure 3), indicating an effect on antigen presentation of viral antigens. Stimulation of monocytes in the PBMC population with compound 1 led to the upregulation of the co-stimulatory molecule CD80 as well as the antigen presenting molecule MHC class II (HLA-DR) (Figure 4). Monocytes differentiated into macrophages also exhibited CD80 upregulation in response to stimulation with compound 1 (Figure 5). Furthermore, PBMCs stimulated with compound 1 expressed an altered cytokine profile with increased production of the immunosuppressive cytokine IL-10, indicating an immune inhibitory effect under certain conditions. Fur- ther analysis of the immunological effect of compound 1 revealed an altered cytokine driven proliferation profile of T cells after six days of stimulation, measured with flow cytometry (Figure 7). In addition, virus-specific T cell proliferation was affected by compound 1. PBMCs from cytomegalovirus (CMV) infected donors cultured in the presence of CMV antigen and compound 1 displayed an altered phenotype of activated CMV- specific CD8+ T cells with an increased expression of IL-7 receptor a (CD127) (Figure 8). CD127 is crucial for T cell homeostasis, differentiation and function, and reduced expression correlates with disease severity in HIV and other chronic viral diseases (Crawley et al. 2012). In summary, compound 1 has a surprising ability to specifically activate and modify an immune response by affecting antigen presentation, co-stimulation and T cell activation and proliferation. In many of the examples presented herein, compound 2 (Figure 1 ), another related macrolide erythromycin analogue with altered glycosylation previously published in Schell et al. 2008 (as compound 20), was included as negative control since it showed little or no activity in the assays.

Thus, in one aspect of the invention, there is provided immune stimulating macrolides of Formula (I) (also referred to as "compound(s) of the invention" and "compounds of Formula (I)") or pharmaceutically acceptable salts hydrates, solvates, tautomers, enan- ti mers thereof:

Formula (I) wherein X is selected from C=0, -NR3CH2-, -CH2NR3-, -NR ₃ (C=0)-, -(C=0)NR ₃ -,

=NOH, and -CH(OH)-, and R ₂ is a sugar of Formula (II) or Formula (III):

Formula (II) Formula wherein Ri is selected from an alkyl, heteroalkyi, cycloalkyi, aryl, and heteroaryl moiety, wherein alkyl moiety is selected from C1-C6 alkyl groups that are optionally branched, wherein heteroalkyi moiety is selected from C1-C6 alkyl groups that are optionally branched or substituted and that optionally comprise one or more heteroatoms, wherein cycloalkyi moiety is selected from a C1-C6 cyclic alkyl groups that are optionally substituted and that optionally comprise one or more heteroatoms,

wherein aryl moiety is selected from optionally substituted C6 aromatic rings, wherein heteroaryl moiety is selected from optionally substituted C1-C5 aromatic rings comprising one or more heteroatoms,

wherein heteroatoms are selected from O, N, P, and S, wherein substituents, independently, are selected from alkyl, OH, F, CI, NH2, NH-alkyl, NH-acyl, S-alkyl, S-acyl, O-alkyl, and O-acyl,

wherein acyl is selected from C1-C4 optionally branched acyl groups, wherein R3 is selected from H and Me,

wherein R ₄ is selected from H and Me, wherein R _a is selected from H and -CR21 R22R23,

wherein R21, R22, R23, and R5, R6, R7, Rs, R9, and R10, independently, are selected from H, Me, NR11 R12, N0 ₂ , and ORn, wherein R23 together with R ₄ in Formula (II), R ₄ together with R5 in Formula (II), R5 together with R ₇ in Formula (II), and R ₇ together with R ₉ in Formula (II), independently, may be joined to represent a bond to leave a double bond between the carbon atoms that each group is connected to, so that wherein if R23 and R ₄ are joined to form a double bond, then Formula (II) can be repres nted by:

wherein if R ₄ and R5 are joined to form a double bond, then Formula (II) can be represented by:

wherein if R5 and R ₇ are joined to form a double bond, then Formula (II) can be represented by:

wherein if R ₇ and Rg are joined to form a double bond, then Formula (II) can be represented by:

wherein R ₄ together with R5 in Formula (III), R ₄ together with R ₇ in Formula (III), and R ₇ together with Rg in Formula (III), independently, may be joined to represent a bond to leave a double bond between the carbon atoms that each group is connected to, so that wherein if R ₄ and R5 are joined to form a double bond, then Formula (III) can be represented by:

wherein if R ₄ and R ₇ are joined to form a double bond, then Formula (III) can be repre- sented by:

wherein if R ₇ and Rg are joined to form a double bond, then Formula (III) can be repre- sented by:

wherein R21 together with R22, R5 together with R6, R ₇ together with Re, or Rg together with R10 may be replaced with a carbonyl,

wherein Rn and R12, independently, are selected from H and alkyl,

wherein R13 is selected from H, OH, and OCH3,

wherein R14 is selected from H and OH, and wherein one of R5, R6, R7, Rs, Rg or R10 is selected from N R11 R12 and NO2, with the proviso that when Ri is Et, R2 is a sugar of Formula (II), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is H, R ₆ is OH, R ₇ is H, R ₈ is NR11 R12, Rg is H, and R10 is H, X may not be C=0,

with the proviso that when Ri is Et, R ₂ is a sugar of Formula (II), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is OH, R ₆ is H, R ₇ is OH, R ₈ is Me, Rg is H, and R10 is H, X may not be C=0, with the proviso that when Ri is Et, R2 is a sugar of Formula (I I ), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is OH, R ₆ is H, R ₇ is H, R ₈ is N R11 R12, R9 is H, and R10 is OH, X may not be C=0. In another aspect of the invention, there is provided immune stimulating macrolides of Formula (I) or pharmaceutically acceptable salts hydrates, solvates, tautomers, enanti- ers thereof:

Formula (I ) wherein X is selected from C=0, -N R3CH2-, and -CH(OH)-, and R2 is a sugar of For- mula (I I):

Formula (I I ) wherein Ri is selected from and alkyi or cycloalkyl moiety,

wherein alkyi moiety is selected from C1-C6 alkyi groups that are optionally branched and, independently, optionally hydroxylated,

wherein cycloalkyl moiety is selected from C1-C6 optionally substituted cyclic alkyi groups,

wherein substituents are selected from alkyi and OH, wherein R3 is selected from H and Me,

wherein R ₄ is selected from H and Me, wherein R _a is selected from H and -CR21 R22R23,

wherein R21 , R22, R23, and R5, R6, R7, Rs, R9, and R10, independently, are selected from H, Me, N R11 R12, N0 ₂ , and ORn , wherein R23 together with R ₄ in Formula (II), R ₄ together with R5 in Formula (II), R5 together with R ₇ in Formula (II), and R7 together with R9 in Formula (II), independently, may be joined to represent a bond to leave a double bond between the carbon atoms that each group is connected to, so that wherein if R23 and R ₄ are joined to form a double bond, then Formula (II) can be repres nted by:

wherein if R ₄ and R5 are joined to form a double bond, then Formula (II) can be represented by:

wherein if R5 and R ₇ are joined to form a double bond, then Formula (II) can be represented by:

wherein if R ₇ and R ₉ are joined to form a double bond, then Formula (II) can be repre- sented by:

wherein R21 together with R22, R5 together with R ₆ , R ₇ together with Re, or R ₉ together with Rio may be replaced with a carbonyl,

wherein Rn and R12, independently, are selected from H and alkyl, wherein R13 is selected from H, OH, and OCH3,

wherein R14 is selected from H and OH, and wherein one of R5, R6, R7, Rs, R9 or R10 is selected from N R11 R12 and NO2, with the proviso that when Ri is Et, R2 is a sugar of Formula (II), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is H, R ₆ is OH, R ₇ is H, R ₈ is N R11 R12, R ₉ is H, and R _i0 is H, X may not be C=0.

with the proviso that when Ri is Et, R ₂ is a sugar of Formula (II), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is OH, R ₆ is H, R ₇ is OH, R ₈ is Me, R ₉ is H, and R10 is H, X may not be C=0.

with the proviso that when Ri is Et, R2 is a sugar of Formula (II), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is OH, R ₆ is H, R ₇ is H, R ₈ is N R11 R12, R ₉ is H, and R10 is OH, X may not be C=0.

In another aspect of the invention, there is provided a method for producing a com- pound of formula (I), which involves addition of an aglycone with formula IV to a culture of a biotransformation strain which glycosylates at the 3-hydroxyl position.

Formula IV

In a preferred embodiment of this aspect of the invention, the biotransformation strain expresses glycosyltransferases with 70% or more homology to AngMII (SEQ ID no. 1 ) or AngMIII (SEQ ID no. 2), such as with 75% or more, with 80% or more, with 90% or more or with 95% or more homology such as 100% homology. The homology between two amino acid sequences or between two nucleic acid sequences is described by the parameter "identity". Alignments of sequences and calculation of homology scores may be done using e.g. a full Smith-Waterman alignment, useful for both protein and DNA alignments. The default scoring matrices BLOSUM50 and the identity matrix are used for protein and DNA alignments respectively. The penalty for the first residue in a gap is -12 for proteins and -16 for DNA, while the penalty for additional residues in a gap is -2 for proteins and -4 for DNA. Alignment may be made with the FASTA package version v20u6. Multiple alignments of protein sequences may be made using "ClustalW". Multiple alignments of DNA sequences may be done using the protein alignment as a template, replacing the amino acids with the corresponding codon from the DNA sequence. Alternatively, different software can be used for aligning amino acid sequences and DNA sequences. The alignment of two amino acid sequences is e.g. determined by using the Needle program from the EMBOSS package (http://emboss.org) version 2.8.0. The substitution matrix used is BLOSUM62, gap opening penalty is 10, and gap extension penalty is 0.5.

An interesting selection of compounds of the invention are compounds wherein F¾ is selected from L-daunosamine , L-acosamine, L-ristosamine, D-ristosamine, 4-oxo-L- vancosamine, L-vancosamine, D-forosamine, L-actinosamine, 3-epi-L-vancosamine, L-vicenisamine, L-mycosamine, D-mycosamine, D-3-N-rnethyl-4-0-methyl-L-ristosa- mine, D-desosamine, N,N-dimethyl-L-pyrrolosamine, L-megosamine, L-nogalamine, L- rhodosamine , D-angolosamine, L-kedarosamine, 2'-N-methyl-D-fucosamine, 3-N,N- dimethyl-L-eremosamine, D-ravidosamine, 3-N,N-dimethyl-D-mycosamine/D-mycami- nose, 3-N-acetyl-D-ravidosamine, 4-O-acetyl-D-ravidosamine, 3-N-acetyl-4-0-acetyl-D- ravidosamine, D-glucosamine, N-acetyl-D-glucosamine, L-desosamine, D-amosamine, D-viosamine, L-avidinosamine, D-gulosamine, D-allosamine, and L-sibirosamine.

Yet another interesting selection of compounds of the invention are compounds wherein R ₂ is selected from D-angolosamine, N-desmethyl D-angolosamine, N- didesmethyl D-angolosamine, N-desmethyl N-ethyl D-angolosamine, and N- didesmethyl N-diethyl D-angolosamine.

Yet another interesting selection of compounds of the invention are compounds wherein F¾ is selected from N-desmethyl D-angolosamine, N-didesmethyl D-ango- losamine, N-desmethyl N-ethyl D-angolosamine, and N-didesmethyl N-diethyl D-angolosamine. Yet another interesting selection of compounds of the invention is compounds wherein R2 is a sugar according to Formula (II). Yet another interesting selection of compounds of the invention are compounds wherein R2 is a sugar according to formula 2 wherein R _a is H, R ₄ is Me, R5 is H, R6 is OH, R ₇ is H, R ₈ is NR11 R12, R9 is H and R10 is H.

Yet another interesting selection of compounds of the invention are compounds wherein Rn is selected from H, Me, and Et, and R12 is selected from H, Me, and Et.

Yet another interesting selection of compounds of the invention are compounds wherein Rn is Et and R12 is Et. Yet another interesting selection of compounds of the invention are compounds wherein Rn is Me and R12 is Et.

Yet another interesting selection of compounds of the invention is compounds wherein X is selected from C=0, -NR3CH2- and -CH(OH)-

Yet another interesting selection of compounds of the invention is compounds wherein Ri is selected from Me, Et, and cycloalkyl.

Yet another interesting selection of compounds of the invention are compounds wherein Ri is selected from Me and Et.

Yet another interesting selection of compounds of the invention are compounds wherein X is selected from -NR ₃ CH ₂ - or -CH ₂ NR ₃ -. Yet another interesting selection of compounds of the invention are compounds wherein one of R5, R6, R7, or R ₈ , is NR11 R12.

Yet another interesting selection of compounds of the invention are compounds wherein R21, R22, R23, and R5, R6, R7, Rs, R9, and R10, independently, are selected from H, Me, NR11 R12, and OR11. Yet another interesting selection of compounds of the invention are compounds wherein R13 and R14 are OH.

Of particular interest are compounds of Formula (I), wherein Ri is Et, R ₂ is a sugar of Formula (II), R13 is OH, R14 is H, R _a is H, R ₄ is Me, R ₅ is H, R ₆ is OH, R ₇ is H, R ₈ is NR11 R12, R9 is H, R10 is H, and X is C=0.

Specific compounds according to the invention include:

As seen from the examples herein some of the compounds of the invention are without substantial antibacterial activity as defined herein.

General Preparation Methods

The skilled person will recognise that compounds of the invention may be prepared, us- ing known methods, in a variety of ways. The routes below are merely illustrative of some methods that can be employed for the preparation of compounds of Formula (I).

Where an aglycone is required for biotransformation these can be accessed in a number of ways. Azithromycin and erythromycin are readily available and considered suita- ble starting points. The mycarose/cladinose and/or desosamine are removed by chemical methods, such as glycoside cleavage. Briefly, in one method the sugars may be removed by treatment with acid. In order to facilitate removal of the amino sugar it is first necessary to oxidise the dimethylamine to form an N-oxide which is then removed by pyrolysis. The resulting 5-0/3-0 sugars can then be removed by acidic degradation. A suitable method is taught by LeMahieu et al. 1974 and Djokic et al. 1988. Finally, the compound is biotransformed using a bacterial strain which adds the amino sugar.

Another route to suitable aglycones is by fermentation and isolation from a suitable blocked mutant. For example, erythronolide B (3a) can be generated by fermentation of strains of S. erythraea blocked in glycosylation, such as strains and processes described, for example, in US. 3, 127,315 (e.g. NRRL2361 , NRRL2360, NRRL2359 and NRRL2338), Gaisser et al. 2000 (e.g. S. erythraea DM ABV ACIII). Briefly, the fermentation is conducted by methods known in the art. Typically, a seed culture is prepared and transferred to a production vessel. The production phase is between 4 and 10 days and the organism is grown between 24°C and 30°C with suitable agitation and aeration. The aglycone can then be isolated by extraction and purification.

Where an aglycone or compound of the invention possesses an amino sugar or any other tertiary amine and is prepared by fermentation, it will be necessary to extract the bacterial broth and purify the compound. Typically, the bacterial broth is adjusted to between pH 8 and 10, ideally 9.5. The broth can then be extracted with a suitable organic solvent. This solvent not be water miscible and is ideally ethyl acetate, methyl terf-butyl ether (MTBE) or solvents with similar properties. The broth and the solvent are mixed, ideally by stirring, for a period of time, e.g. 30 minutes or 1 hour. The phases are then separated and the organic extracts removed. The broth can be extracted in this manner multiple times, ideally two or three times. The combined organic extracts can then be reduced in vacuo. The residue is then dissolved or suspended in mildly acidic aqueous solvent. Typically, this is an ammonium chloride aqueous solution. This is then ex- tracted with a water-immiscible organic solvent, such as ethyl acetate, a number of times, ideally 2 or 3 times. The resulting aqueous layer is collected and the pH is adjusted to between pH 8 and 10, ideally 9.0. The resultant aqueous layer is then extracted with a water-immiscible organic solvent, such as ethyl acetate, a number of times, ideally 2 or 3 times. The organic extracts are combined and reduced in vacuo to yield a crude extract enhanced in the target compound requiring further purification.

Compound purification can be done by chromatography or (re)crystallisation, and the methods required are well known to a person skilled in the art. Where chromatography is required on normal phase silica and an aglycone or compound of the invention pos- sesses an amino sugar or other tertiary amine, then it is beneficial to add a basic modifier to the mobile phase. For instance, chromatography on normal phase silica can use a hexane, ethyl acetate, methanol system for elution with 0-5% aqueous ammonium hydroxide added. Ideally, 2% aqueous ammonium hydroxide is added. Following biotransformation, both unused aglycone and compound of the invention can be purified separately from the same crude extract using a suitable solvent system. If further purification is required, this may optionally be carried out by preparative HPLC.

Reductive amination to alkylate a primary or secondary amine is well known to a per- son skilled in the art. The amine is mixed in a solvent with an aldehyde or ketone and a reducing agent is added. Sodium borohydride can then reduce the imine or hemiami- nal that results from the reaction of the amine and carbonyl, resulting in e.g. an alkylated amine. Sodium borohydride may also reduce other carbonyl groups present, e.g. ketones. In cases where a ketone also exists, it is preferred to use a reducing agent that is more specific to a protonated imine, such as sodium cyanoborohydride, though it will be obvious to a person skilled in the art that different reducing agents, solvents, temperatures, and reaction times may need to be tested to find the optimal conditions.

General use of the compounds of the invention

Compounds of the invention as described herein can be used in medicine, medical research or in the manufacture of a composition for such use. Accordingly, when in the following the term "compounds of the invention" is used in connection with medical use or pharmaceutical composition, the term is intended also to include the compounds of Formula (I) provided that such compounds have not been known for such a use. In par- ticular, medical use as described herein of the compounds of Formula (I) includes compounds, wherein when Ri is Et, R2 is a sugar of Formula (II), R13 is OH, R14 is H, R _a is H, R ₄ is Me, R ₅ is H, R ₆ is OH, R ₇ is H, R ₈ is NR11 R12, R9 is H, R10 is H, and X is C=0.

The compounds of the invention are designed in order to minimize direct antibacterial effects, but rather focus on immune activating properties. When a compound of the invention is added to cultures of bacteria E. coli, S. salivarius, L casei, B. longum or M. luteus, no or minimal antibacterial effect is recognized. The advantage of having compounds with isolated immune stimulatory properties that affect the host cells is that development of bacterial resistance is avoided. In addition, the well-known side effect of macrolides affecting the gut microbiota, with the risk of overgrowth of Clostridium difficile causing diarrhea and pseudomebraneous colitis, is avoided. Many viruses and cancers have developed mechanisms to avoid immune recognition, i.e. by down regulating HLA expression to avoid detection by T cells. The mechanism of the compounds of the intervention relies on the activation and increased expression of HLA molecules on infected cells. HLA molecules load and present peptides derived from intracellular infectious agents in order to present a recognition signal for T cells allowing elimination of infected cells.

The compounds of the invention disclosed herein may be used to treat diseases, disorders, conditions, and symptoms, where immune response stimulation is useful, such as in treating patients infected with viral agents or with viral diseases such as HIV/AIDS, Adenovirus, Alphavirus, Arbovirus, Borna Disease, Bunyavirus, Calicivirus, Condyloma Acuminata, Coronavirus, Coxsackievirus, Cytomegalovirus, Dengue fever virus, Conta- geous Ecthyma, Epstein-Barr virus, Erythema Infectiosum, Hantavirus, Viral Hemorrhagic Fever, Viral Hepatitis, Herpes Simplex Virus, Herpes Zoster virus, Infectious Mononucleosis, Influenza, Lassa Fever virus, Measles, Mumps, Molluscum Conta- giosum, Paramyxovirus, Phlebotomus fever, Polyoma-virus, Rift Valley Fever, Rubella, Slow Disease Virus, Smallpox, Subacute Sclerosing Panencephalitis, Tumor Virus Infections, West Nile Virus, Yellow Fever Virus, Rabies Virus and Respiratory Syncitial Virus. In particular, compounds of the invention may be used for treatment of

HIV/AIDS.

Moreover, the compounds of the invention are contemplated to be suitable for use in the treatment of cancer, in particular cancers such as Adrenal Cancer, Anal Cancer, Bile Duct Cancer, Bladder Cancer, Bone Cancer, Brain/CNS Tumors, Breast Cancer, Castleman Disease, Cervical Cancer, Colon/Rectum Cancer, Endometrial Cancer, Esophagus Cancer, Eye Cancer, Gallbladder Cancer, Gastrointestinal Carcinoid Tumors, Gastrointestinal Stromal Tumor (GIST), Gestational Trophoblastic Disease, Hodgkin Disease, Kaposi Sarcoma, Kidney Cancer, Laryngeal and Hypopharyngeal Cancer, Acute Myeloid Leukemia, Chronic Lymphocytic Leukemia, Acute Lymphocytic Leukemia, Chronic Myeloid Leukemia, Chronic Myelomonocytic Leukemia, Liver Cancer, Non-Small Cell Lung Cancer, Small Cell Lung Cancer, Lung Carcinoid Tumor, Lymphoma, Malignant Mesothelioma, Multiple Myeloma, Myelodysplasia Syndrome, Nasal Cavity and Paranasal Sinus Cancer, Nasopharyngeal Cancer, Neuroblastoma, Non-Hodgkin Lymphoma, Oral Cavity and Oropharyngeal Cancer, Osteosarcoma, Ovarian Cancer, Pancreatic Cancer, Penile Cancer, Pituitary Tumors, Prostate Cancer, Retinoblastoma, Rhabdomyosarcoma, Salivary Gland Cancer, Basal and Squamous Cell Skin Cancer, Melanoma, Merkel Cell Skin Cancer, Small Intestine Cancer, Stomach Cancer, Testicular Cancer, Thymus Cancer, Thyroid Cancer, Uterine Sarcoma, Vaginal Cancer, Vulvar Cancer, Waldenstrom Macroglobulinemia, and Wilms Tumor.

Thus, the advantageous properties of the compounds of the invention over the prior art macrolides may include one or more of the following:

-Reduced direct antibacterial activity

-Improved MHC class I stimulation

-Improved immunomodulation

-Improved activation of antigen presenting cells

-Improved T-cell response

-Improved antiviral activity

-Improved MHC class II antigen presentation Pharmaceutical compositions comprising a compound of the invention

The present invention also provides a pharmaceutical composition comprising a compound of the invention together with one or more pharmaceutically acceptable diluents or carriers. Similarly, the present invention also provides a pharmaceutical kit comprising at least one pharmaceutical composition comprising a compound of the invention together with one or more pharmaceutically acceptable excipients. The present invention also relates to cosmetic or veterinary compositions comprising a compound of the invention together with one or more cosmetically or veterinary acceptable excipients.

The compounds of the invention or pharmaceutical, cosmetic, or veterinary composi- tions comprising compounds of the invention may be administered by any conventional route such as but not limited to parenteral, oral, topical, or via a mucosa (including buccal, sublingual, transdermal, vaginal, rectal, nasal, ocular, etc.), via a medical device (e.g. a stent), or by inhalation. The treatment may consist of a single administration or a plurality of administrations over a period of time.

The dosage regimen of the compounds of the invention and the pharmaceutical compositions of the invention may be varied depending on the pharmaceutical properties of the compound or composition in question. The dosage regimen may consist of a single administration or a plurality of administrations over one or more periods of time. Admin- istration may be once daily, twice daily, three times daily, four times daily, less frequently, or more frequently, depending on the specific use, the disease to be treated, and the physical condition and characteristics (such as gender, weight, and age) of the patient to be treated. The treatment may also be by continuous administration such as e.g. intravenous administration via a drop or via depots or sustained-release formula- tions. Whilst it is possible for a compound of the invention to be administered as such, it is preferable to present it as a pharmaceutical composition together with one or more pharmaceutically acceptable excipients. The excipient(s) must be "acceptable" in the sense of being compatible with the compound of the invention and not deleterious to the recipients thereof. Examples of suitable excipients are described in more detail below.

The pharmaceutical compositions may conveniently be presented in a suitable dosage form including a unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. Such methods include the step of bringing into association the compound of the invention with one or more excipients. In general, the pharmaceutical compositions are prepared by uniformly and intimately bringing into association the compound of the invention with the excipient(s), and then, if necessary, shaping the resulting composition into e.g. a tablet.

A compound of the invention will normally be administered by any conventional administration route, such as the oral or any parenteral route, in the form of a pharmaceutical composition comprising the compound of the invention, optionally in the form of a pharmaceutically acceptable salt, in a pharmaceutically acceptable dosage form. Depend- ing upon the disorder and patient to be treated, as well as the route of administration, the pharmaceutical composition may be administered at varying doses and/or frequencies.

The pharmaceutical compositions must be stable under the conditions of manufacture and storage; thus, if necessary, they should be preserved against the contaminating action of microorganisms such as bacteria and fungi. In case of liquid formulations such as solutions, dispersion, emulsions, and suspensions, the excipient(s) can be a solvent or dispersion medium such as but not limited to water, ethanol, polyol (e.g. glycerol, propylene glycol and liquid polyethylene glycol), vegetable oils, and suitable mixtures thereof, as well as a solvent or dispersion medium comprising water, ethanol, polyol (e.g. glycerol, propylene glycol and liquid polyethylene glycol), and vegetable oils.

For example, the compounds of the invention may be administered orally, buccally or sublingually in the form of tablets, capsules, films, ovules, elixirs, solutions, emulsions, or suspensions, which may contain flavouring or colouring agents. Pharmaceutical compositions of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets, each containing a predetermined amount of the compound of the invention; as multiple units e.g. in the form of a tablet or capsule; as a powder or granules; as a solution or a suspension in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The pharmaceutical compositions may also be presented as a bolus, electuary, or paste. Solutions or suspensions of the compounds of the invention suitable for oral administration may also contain one or more solvents including water, alcohol, polyol, etc., as well as one or more excipients such as pH-adjusting agents, stabilizing agents, surfactants, solubilizers, dispersing agents, preservatives, flavours, etc. Specific examples include Ν,Ν-dimethylacetamide, polysorbate 80, polyethylene glycol, and Phosal 50 PG (which consists of phosphatidylcholine, soya-fatty acids, ethanol, mono/diglycerides, propylene glycol and ascorbyl palmitate). The pharmaceutical compositions of the present invention may also be in the form of emulsions, wherein a compound according to Formula (I) may be presented in an emulsion such as an oil-in-water emulsion or a water-in-oil emulsion. The oil may be a natural or synthetic oil or any oil-like substance such as e.g. soy bean oil or safflower oil or combinations thereof.

Tablets may contain excipients such as microcrystalline cellulose, lactose (e.g. lactose monohydrate or anhydrous lactose), sodium citrate, calcium carbonate, dibasic calcium phosphate and glycine, butylated hydroxytoluene (E321 ), crospovidone, hypromellose, disintegrants such as starch (preferably corn, potato or tapioca starch), sodium starch glycollate, croscarmellose sodium, and certain complex silicates, and granulation binders such as polyvinylpyrrolidone, hydroxypropylmethylcellulose (HPMC), hydroxy- propylcellulose (HPC), macrogol 8000, sucrose, gelatin, and acacia. Additionally, lubricating agents such as magnesium stearate, stearic acid, glyceryl behenate, and talc may be included.

A tablet may be made by compression or moulding of a compounds of the invention, optionally with one or more excipients. Compressed tablets may be prepared by compressing in a suitable machine the compound of the invention in a free-flowing form such as a powder or granules, optionally mixed with a binder (e.g. povidone, gelatin, hydroxypropylmethyl cellulose), lubricant, inert diluent, preservative, disintegrant (e.g. sodium starch glycolate, cross-linked povidone, cross-linked sodium carboxymethyl cellulose), surface-active agent, and/or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compound of the invention moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be further treated of processed to provide slow or controlled release of the compound of the invention contained therein using, for example, hydroxypropyl- methylcellulose in varying proportions to provide desired release profile.

Solid pharmaceutical compositions of a similar type may also be employed as fillers in gelatin capsules. Preferred excipients in this regard include lactose, starch, cellulose, milk sugar, and high molecular weight polyethylene glycols. For aqueous suspensions and/or elixirs, the compounds of the invention may be combined with various sweetening or flavouring agents, colouring matter or dyes, with emulsifying and/or suspending agents, and with diluents such as water, ethanol, propylene glycol and glycerin, and combinations thereof.

Pharmaceutical compositions of the invention suitable for topical administration in the oral cavity include lozenges comprising a compound of the invention in a flavoured basis, usually sucrose and acacia or tragacanth; pastilles comprising a compound of the invention in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouth-washes comprising a compound of the invention in a suitable liquid carrier.

Pharmaceutical compositions of the invention adapted for topical administration may be prepared as ointments, creams, suspensions, lotions, powders, solutions, pastes, gels, impregnated dressings, sprays, aerosols or oils, transdermal devices, dusting powders, and the like. Such compositions may be prepared via conventional methods containing a compound of the invention. Thus, they may also comprise compatible excipients, such as preservatives, solvents to assist drug penetration, emollient in creams or ointments, and ethanol or oleyl alcohol in lotions. Excipients may constitute from about 1 % w/w to about 98% w/w of the composition. Preferably, excipients constitute up to about 80% w/w of the composition. As an illustration only, a cream or ointment is prepared by mixing sufficient quantities of hydrophilic material and water, containing from about 5- 10% w/w of the compound, in sufficient quantities to produce a cream or ointment having the desired consistency.

Pharmaceutical compositions of the invention adapted for transdermal administration may be presented as discrete patches intended to remain in intimate contact with the epidermis of the recipient for a prolonged period of time. For example, a compound of the invention may be delivered from the patch by iontophoresis. For applications to external tissues, for example the mouth and skin, the pharmaceutical compositions of the invention are preferably applied as a topical ointment or cream. When formulated in an ointment, a compound of the invention may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, a compound of the invention may be formulated in a cream with an oil-in- water cream base or a water-in-oil base.

For parenteral administration, fluid unit dosage forms are prepared comprising a compound of the invention and a sterile vehicle, such as but not limited to water, alcohols, polyols, glycerine, and vegetable oils, with water being preferred. The compound of the invention, depending on the vehicle and concentration used, can be either colloidal, suspended, or dissolved in the vehicle. In preparing solutions, the compound of the invention can be dissolved in water for injection and filter sterilised before filling into a suitable vial or ampoule and sealing.

Advantageously, agents such as local anaesthetics, preservatives, and buffering agents can be dissolved in the vehicle. To enhance the stability, the pharmaceutical composition can be frozen after filling into the vial, and the water may then be removed under vacuum. The dry lyophilized powder is then sealed in the vial and an accompa- nying vial of water for injection may be supplied to reconstitute the liquid prior to use.

Pharmaceutical compositions of the present invention suitable for injectable use include sterile aqueous solutions or dispersions. Furthermore, such pharmaceutical compositions can be in the form of sterile powders for the extemporaneous preparation of such sterile injectable solutions or dispersions. In all cases, the final injectable form must be sterile and must be effectively fluid for easy syringability.

Parenteral suspensions are prepared in substantially the same manner as solutions, except that the compound of the invention is suspended in the vehicle instead of being dissolved, and sterilization cannot be accomplished by filtration. The compound of the invention can be sterilised by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the pharmaceutical composition to facilitate uniform distribution of the compound of the invention. It should be understood that in addition to the ingredients particularly mentioned above, the pharmaceutical compositions of the present invention may include other agents conventional in the art having regard to the type of formulation in question. For example, those pharmaceutical compositions suitable for oral administration may include flavouring agents. A person skilled in the art will know how to choose a suitable formula- tion and how to prepare it, e.g. with guidance from Remington's Pharmaceutical Sciences, 18 ^th edition, Mack Publishing Company, 1990, or a newer edition. A person skilled in the art will also know how to choose a suitable administration route and dosage. It will be recognized by a person skilled in the art that the optimal quantity and spacing of individual dosages of a compound of the invention will be determined by the nature and extent of the condition being treated, the form, route and site of administration, and the age and condition of the particular subject being treated, and that a physician will ultimately determine appropriate dosages to be used. This dosage may be repeated as often as appropriate. If side effects develop, the amount and/or frequency of the dosage can be altered or reduced, in accordance with normal clinical practice.

All % values mentioned herein are % w/w unless the context requires otherwise. Definitions

The articles "a", "an", and "the" are used herein to refer to one or to more than one (i.e. at least one) of the grammatical objects of the article. By way of example "an analogue" means one analogue or more than one analogue. As used herein the terms "compound(s) of the invention" and "compounds of Formula (I)" are used interchangeably and refer to compounds of Formula (I).

As used herein the term "direct antibacterial effect" refers to the antibacterial activity of erythromycin and analogues which occurs through binding to the bacterial rRNA complex. This effect does not require presence of any host immune system components and therefore is apparent in standard antibacterial assays such as in vitro Minimum Inhibitory Concentration (MIC) assays and disk inhibition assays.

As used herein the term "without substantial antibacterial activity" is intended to mean that the compound of the invention has a MIC value of >64 μg/ml when tested in accordance with Example 13 herein for its antibacterial activity in E. coli, S. salivarius, L casei and B. longum.

As used herein the term "alkyl" refers to any straight or branched chain composed of only sp3-hybridized carbon atoms, fully saturated with hydrogen atoms such as e.g. - C _n H ₂ n+i for straight chain alkyls, wherein n can be in the range of 1 and 6 such as e.g. methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, neopen- tyl, isopentyl, hexyl or isohexyl. The alkyl as used herein may be further substituted. The term "heteroalkyl" in the present context designates a group -X-C-1 -6 alkyl used alone or in combination, wherein C1 -6 alkyl is as defined above and X is O, S, NH or N- alkyl. Examples of linear heteroalkyl groups are methoxy, ethoxy, propoxy, butoxy, pentoxy and hexoxy. Examples of branched heteroalkyl are iso-propoxy, sec-butoxy, tert-butoxy, iso-pentoxy and iso-hexoxy. Examples of cyclic heteroalkyl are cyclopropy- loxy, cyclobutyloxy, cyclopentyloxy and cyclohexyloxy. The heteroalkyl as used herein may be further substituted.

As used herein the term "cycloalkyl" refers to a cyclic/ring structured carbon chains having the general formula of -CnHbn-i where n is between 3-6, such as e.g. cyclopro- pyl, cyclobytyl, cyclopentyl or cyclohexyl and the like. The cycloalkyl as used herein may be further substituted or contain a heteroatom (O, S, NH or N-alkyl) in the cyclic structure.

The term "aryl" as used herein is intended to include carbocyclic aromatic ring systems. Aryl is also intended to include the partially hydrogenated derivatives of the carbocyclic systems enumerated below.

The term "heteroaryl" as used herein includes heterocyclic unsaturated ring systems containing one or more heteroatoms selected among nitrogen, oxygen and sulphur, such as furyl, thienyl, pyrrolyl, and is also intended to include the partially hydrogenated derivatives of the heterocyclic systems enumerated below. The terms "aryl" and "heteroaryl" as used herein refers to an aryl, which can be optionally unsubstituted or mono-, di- or tri substituted, or a heteroaryl, which can be optionally unsubstituted or mono-, di- or tri substituted. Examples of "aryl" and "heteroaryl" in- elude, but are not limited to, phenyl, biphenyl, indenyl, naphthyl (1-naphthyl, 2-naph- thyl), N-hydroxytetrazolyl, N-hydroxytriazolyl, N-hydroxyimidazolyl, anthracenyl (1 -an- thracenyl, 2-anthracenyl, 3-anthracenyl), phenanthrenyl, fluorenyl, pentalenyl, azulenyl, biphenylenyl, thiophenyl (1-thienyl, 2-thienyl), furyl (1 -furyl, 2-furyl), furanyl, thiophenyl, isoxazolyl, isothiazolyl, 1 ,2,3-triazolyl, 1 ,2,4-triazolyl, pyranyl, pyridazinyl, pyrazinyl, 1 ,2,3-triazinyl, 1 ,2,4-triazinyl, 1 ,3,5-triazinyl, 1 ,2,3-oxadiazolyl, 1 ,2,4-oxadiazolyl, 1

, 2,5-oxadiazolyl, 1 ,3,4-oxadiazolyl, 1 ,2,3-thiadiazolyl, 1 ,2,4-thiadiazolyl, 1 ,2,5-thiadia- zolyl, 1 ,3,4-thiadiazolyl, tetrazolyl, thiadiazinyl, indolyl, isoindolyl, benzofuranyl, ben- zothiophenyl (thianaphthenyl), indolyl, oxadiazolyl, isoxazolyl, quinazolinyl, fluorenyl, xanthenyl, isoindanyl, benzhydryl, acridinyl, benzisoxazolyl, purinyl, quinazolinyl, quino- lizinyl, quinolinyl, isoquinolinyl, quinoxalinyl, naphthyridinyl, phteridinyl, azepinyl, diaze- pinyl, pyrrolyl (2-pyrrolyl), pyrazolyl (3-pyrazolyl), 5-thiophene-2-yl-2H-pyrazol-3-yl, im- idazolyl (1 -imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl), triazolyl (1 ,2,3-triazol-1- yl, 1 ,2,3-triazol-2-yl, 1 ,2,3-triazol-4-yl, 1 ,2,4-triazol-3-yl), oxazolyl (2-oxazolyl, 4-oxa- zolyl, 5-oxazolyl), thiazolyl (2-thiazolyl, 4-thiazolyl, 5-thiazolyl), pyridyl (2-pyridyl, 3- pyridyl, 4-pyridyl), pyrimidinyl (2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl), pyrazinyl, pyridazinyl (3-pyridazinyl, 4-pyridazinyl, 5-pyridazinyl), isoquinolyl (1 -iso- quinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-iso- quinolyl), quinolyl (2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8- quinolyl), benzo[b]furanyl (2-benzo[b]furanyl, 3-benzo[b]furanyl, 4-benzo[b]furanyl, 5- benzo[b]furanyl, 6-benzo[b]furanyl, 7-benzo[b]furanyl), 2,3-dihydro-benzo[b]furanyl (2- (2,3-dihydro-benzo[b]furanyl), 3-(2,3-dihydro-benzo[b]furanyl), 4-(2,3-dihydro- benzo[b]furanyl), 5-(2,3-dihydro-benzo[b]furanyl), 6-(2,3-dihydro-benzo[b]furanyl), 7- (2,3-dihydro-benzo[b]furanyl)), benzo[b]thiophenyl (2-benzo[b]thiophenyl, 3- benzo[b]thiophenyl, 4-benzo[b]thiophenyl, 5-benzo[b]thiophenyl, 6-benzo[b]thiophenyl, 7-benzo[b]thiophenyl), 2,3-dihydro-benzo[b]thiophenyl (2-(2,3-dihydro-benzo[b]thio- phenyl), 3-(2,3-dihydro-benzo[b]thiophenyl), 4-(2,3-dihydro-benzo[b]thiophenyl), 5-(2,3- dihydro-benzo[b]thiophenyl), 6-(2,3-dihydro-benzo[b]thiophenyl), 7-(2,3-dihydro- benzo[b]thiophenyl)), indolyl (1 -indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6-in- dolyl, 7-indolyl), indazolyl (1 -indazolyl, 2-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl), benzimidazolyl, (1-benzimidazolyl, 2-benzimidazolyl, 4-ben- zimidazolyl, 5-benzimidazolyl, 6-benzimidazolyl, 7-benzimidazolyl, 8-benzimidazolyl), benzoxazolyl (1 -benzoxazolyl, 2-benzoxazolyl), benzothiazolyl (1 -benzothiazolyl, 2- benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl), carbazolyl (1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl). Non-limiting examples of partially hydrogenated derivatives are 1 ,2,3,4-tetrahydronaphthyl, 1 ,4-dihy- dronaphthyl, pyrrolinyl, pyrazolinyl, indolinyl, oxazolidinyl, oxazolinyl, oxazepinyl and the like.

The pharmaceutically acceptable salts of the compound of the invention include conventional salts formed from pharmaceutically acceptable inorganic or organic acids or bases as well as quaternary ammonium acid addition salts. More specific examples of suitable acid salts include hydrochloric, hydrobromic, sulfuric, phosphoric, nitric, perchloric, fumaric, acetic, propionic, succinic, glycolic, formic, lactic, maleic, tartaric, citric, palmoic, malonic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, toluenesul- fonic, methanesulfonic, naphthalene-2-sulfonic, benzenesulfonic hydroxynaphthoic, hy- droiodic, malic, steroic, tannic and the like. Other acids such as oxalic, while not in themselves pharmaceutically acceptable, may be useful in the preparation of salts useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable salts. More specific examples of suitable basic salts include sodium, lithium, potassium, magnesium, aluminium, calcium, zinc, N,N'-dibenzylethylenedia- mine, chloroprocaine, choline, diethanolamine, ethylenediamine, N-methylglucamine and procaine salts.

Legends to figures

Figure 1 . The structures of the macrolides Erythromycin A, Compound 1 , Compound A, compound B and EM703.

Figure 2. CD69 upregulation on T- and B- cells. PBMC were treated for 24h with compound 1 , compound A and activation controls LPS and IFN-gamma. The expression of the early activation marker CD69 was measured on the CD4+ T cell population (left) and CD19+ B cell population (right) with flow cytometry. Values represents mean fluo- rescent intensity, MFI, and error bars standard deviation in the triplicate samples.

Figure 3. HLA-A,B,C upregulation on T- and B- cells. PBMC were treated for 24h with compounds 1 or A and activation controls LPS and IFN-γ. The expression of HLA- A,B,C was measured on the CD4+ T cell population (left) and CD19+ B cell population (right) with flow cytometry. Values represents mean fluorescent intensity, MFI, and error bars standard deviation in the triplicate samples.

Figure 4. CD80 and HLA-DR upregulation on blood monocytes. PBMC were treated for 24h with compounds 1 or A as well as activation controls LPS and IFN-gamma. The expression of CD80 and HLA-DR was measured on the monocyte cell population with flow cytometry. Values represents mean fluorescent intensity, MFI, and error bars standard deviation in the triplicate samples. Figure 5. CD80 upregulation on blood monocytes. PBMC were treated for 24h with compounds 1 or A as well as activation control IFN-gamma. The expression of CD80 was measured on the monocyte cell population with flow cytometry. Values represents mean fluorescent intensity, MFI, and error bars standard deviation in the triplicate samples.

Figure 6. Production of IL-10 from PBMCs after stimulation with compound 1 for 48h or 1 week, measured with ELISA.

Figure 7. CD4 T cell proliferation after 6 days stimulation with compound 1 , measured with proliferation dye Celltrace violet (Invitrogen) and flow cytometry. Untreated cells (UNT) or compound A were used as controls.

Figure 8. Upregulation of IL-7 receptor a (CD127) on CMV specific CD8 T cells after incubation with compound 1 , measured with flow cytometry.

Figure 9: Interferon-gamma secretion (as measured by cytometric bead assay) from PBMCs (from a CMV+ donor) grown with CMV peptides in the presence or absence of compound 1 or A for 5 days. Figure 10: Interferon-gamma secretion (as measured by cytometric bead assay) from macrophages stimulated with indicated compound for 48h.

Figure 1 1 : Chemokine RANTES secretion (as measured by cytometric bead assay) from PBMC or macrophages stimulated with indicated compound for 48h.

Figure 12: IL12p70 secretion (as measured by cytometric bead assay) from PBMC or macrophages stimulated with indicated compound for 48h.

Figure 13: I L1 b secretion (as measured by cytometric bead assay) from PBMC, macrophages or CD4 T cells stimulated with indicated compound for 48h.

Figure 14: %CD25high cells in blood of C57bl/6 mice injected 24h previously with indicated dose of compound 1. CD25 expression was measured by flow cytometry.

Figure 15: %MHC class I high CD1 1 b+ cells in spleen of 3 individual C57bl/6 mice in- jected 24h previously with indicated compound. MHC class I and CD1 1 b expression was measured by flow cytometry.

Experimental

Materials

Unless otherwise indicated, all reagents used in the examples below are obtained from commercial sources. Example suppliers of Azithromycin B include Santa Cruz Biotechnology (Texas, USA) and Toronto Research Chemicals (Toronto, Canada).

Antibodies

Anti-CD80 V450, anti-CD69 PE, anti HLA-DR APC-R700, anti CD127-APC, and anti- Anti-HLA-A,B,C FITC were purchased from BD Biosciences. Celltrace violet for T cell proliferation assay was purchased from Invitrogen. ELISA antibodies were purchased from BD Biosciences. Media

RPMI-1640 (Invitrogen) supplemented with 25mM HEPES, L-glutamine, Sodium pyruvate, 10% fetal bovine serum (Gibco), 100μg/mL penicillin and 100 μg/mL streptomycin General Biology Methods

The effect of the compounds of the invention on immune stimulation may be tested using one or more of the methods described below:

General Compound Method

Compound analysis - solubility and stability in solution Analysis of fermentation broths and compounds

An aliquot of fermentation broth obtained as described below was shaken vigorously for 30 minutes with an equal volume of ethyl acetate, and then separated by centrifugation, or the already isolated compounds were dissolved in methanokwater (9:1 , 0.1 mg/ml), and then separated by centrifugation. Supernatants were analysed by LC-MS and LC-MS/MS and chromatography was achieved over base-deactivated Luna C18 reversed-phase silica (5 micron particle size) using a Luna HPLC column (250 ^χ 4.6 mm; Phenomenex (Macclesfield, UK)) heated at 40 °C. Agilent 1 100 HPLC system comprising of quaternary pump, auto sampler, column oven and diode array detector coupled to a Bruker Esquire ion trap MS.

Mobile phase A = 0.1 % formic acid in water

Mobile phase B = 0.1 % formic acid in acetonitrile Gradient: T= 0 min, B = 50%; T= 4.5 min, B = 50%; T = 7 min, B = 100 %; T= 10.5 min, B = 100 %; T = 10.75 min, B = 50 %; T = 13 min, B = 50%.

Compounds were identified by LC-MS and LC-MS/MS and quantified by LC-MS/MS against an internal standard. Analysis of marker expression by flow cytometry

Human peripheral blood mononuclear cells (PBMCs) were purified from healthy donors with Ficoll-Paque density centrifugation. Cells were cultured in complete RPMI-1640 media (Invitrogen) supplemented with 25mM HEPES, L-glutamine, Sodium pyruvate (Sigma), 10% fetal bovine serum, 100μg/mL penicillin and 100 μg/mL streptomycin (Hyclone) for 24-72 hours in 37 °C, 5% C02 and stimulated with and increasing concentrations of compound 1 and 2. Cells were then washed in PBS and stained with monoclonal antibodies specific for cell surface markers (BD Pharmingen) and analysed with flow cytomtetry using a BD FACS Canto II flow cytometer. All samples were tested in duplicates.

Cytomegalovirus (CMV) cultures

Human peripheral blood mononuclear cells (PBMCs) were purified from healthy CMV positive donors with Ficoll-Paque density centrifugation. The PBMC were labeled with 5 μΜ celltrace violet (Invitrogen) in PBS for 15 minutes and then washed with complete cell culture medium. The labeled PBMC was cultured in the presence of a peptide library spanning the CMV pp65 protein (1 μg peptide/ml, JPT) in AIM-V media (Invitro- gen) supplemented with L-glutamine, Sodium pyruvate (Sigma), 10% fetal bovine serum, 100μg/mL penicillin and 100 μg/mL streptomycin (Hyclone) for 6-8 days in 37 °C, 5% CO2. Cell proliferation was assessed with flow cytomtery using a BD FACS Canto II flow cyto meter.

ELISA

Supernatant IL-10 was measured with a standard sandwich ELISA (all antibodies from BD Biosciences) after 48 hours and 7 days incubation with 2.5 μΜ of compound 1 and 100 U/mL IL-2 (Miltenyi Biotechnologies) in complete RPMI media, 37 °C, 5% C0 ₂

TLR2 assay

Samples and controls were tested in duplicate on recombinant HEK-293-TLR cell lines using a cell reporter assay at Invivogen using their standard assay conditions. These cell lines functionally over-express human TLR2 protein as well as a reporter gene which is a secreted alkaline phosphatase (SEAP). The production of this reporter gene is driven by an NFkB inducible promoter. The TLR reporter cell lines activation results are given as optical density values (OD).

20 μΙ of each test article were used to stimulate the hTLR2 reporter cell lines in a 200μΙ of final reaction volume. Samples were tested in duplicate, with at least two concentrations tested - 20uM and 10uM.

Assessment of cell permeability (bidirectional)

10μΜ Test article was added to the apical (A) surface of Caco-2 cell monolayers (in HBSS buffer with 0.3% DMSO and 5 μΜ LY at 37 degrees C) and compound permeation into the basolateral (B) compartment measured following 90 minutes incubation. This was also performed in the reverse direction (basolateral to apical) to investigate active transport. LC-MS/MS is used to quantify levels of both the test and standard control compounds. Efflux ratio was calculated by dividing the B to A permeability by the A to B permeability.

Drug permeability: Papp = (VA / (Area ^χ time)) ^χ ([drug]accepter /(([drug]initial, donor) xDilution Factor) Assessment of metabolic stability (microsome stability assay)

Rate of metabolism in microsomes was tested as follows: Human liver microsomes were diluted with buffer C (0.1 M Potassium Phosphate buffer, 1 .0 mM EDTA, pH 7.4) to a concentration of 2.5 mg/mL. Microsomal stability studies were carried out by adding 30 μΙ_ of 1 .5 μΜ compound spiking solution to wells (1.5 μΙ_ of 500 μΜ spiking solution (10 μί of 10 mM DMSO stock solution into 190 μΙ_ ACN to eventually generate final test concentration of 1 uM) and 18.75 μΙ_ of 20 mg/mL liver microsomes into 479.75 μΙ_ of Buffer C). All samples were pre-incubated for approximately 15 minutes at 37°C. Following this, the reaction was initiated by adding 15 μΙ_ of the NADPH solution (6 mM) with gentle mixing. Aliquots (40 μΙ_) were removed at 0, 5, 15, 30 and 45 minutes and quenched with ACN containing internal standard (135 μΙ_). Protein was removed by centrifugation (4000 rpm, 15 min) and the sample plate analysed for compound concentration by LC-MS/MS. Half-lives were then calculated by standard methods, comparing the concentration of analyte with the amount originally present. Examples

Example 1 - Preparation of compound 1

1a 1

Preparation of Azithromycin Aglycone (Az-AG) (1a)

Azithromycin aglycone (1a) was generated using methods described in the literature (Djokic et al. 1988). In brief, azithromycin is converted to azithromycin aglycone by the acidic removal of the 3-0 and 5-0 sugars. The 5-0 amino sugar is first oxidised and pyrolyzed to facilitate cleavage.

Generation of biotransformation strains capable of glycosylating erythromycin agly- cones (erythronolides):

Generation of S. erythraea 18A 1 (pAES52)

pAES52, an expression plasmid containing angAI, angAII, angCVI, ang-orf14, angMIII, angB, angMl and angMII along with the acf//-ORF4 pactl/lll expression system (Rowe et al. 1998) was generated as follows.

The angolamycin sugar biosynthetic genes were amplified from a cosmid library of strain S. eurythermus ATCC23956 obtained from the American Type Culture Collection (Manassas, Virginia, USA). The biosynthetic gene cluster sequence was deposited as EU038272, EU220288 and EU232693 (Schell et al. 2008).

The biosynthetic gene cassette was assembled in the vector pSG144 as described previously (Schell et al. 2008, ESI), adding sequential genes until the 8 required for sugar biosynthesis were obtained, creating plasmid pAES52. pAES52 was transformed into strain 18A1 (WO2005054265).

Transformation of pAES52 into S. erythraea 18A 1

pAES52 was transformed by protoplast into S. erythraea 18A1 using standard methods (Kieser et al. 2000, Gaisser et al. 1997). The resulting strain was designated ISOM- 4522, which is deposited at the NCIMB on 24 January 2017 with Accession number: NCIMB 42718. Generation of S. erythraea SGT2 (pAES54)

pAES54, an expression plasmid containing angAI, angAII, angCVI, ang-orf14, angMIII, angB, angMl and angMII along with the acf//-ORF4 pactl/lll expression system (Rowe et al., 1998) was generated as follows The angolamycin sugar biosynthetic genes were amplified from a cosmid library of strain S. eurythermus ATCC23956 obtained from the American Type Culture Collection (Manassas, Virginia, USA). The biosynthetic gene cluster sequence was deposited as EU038272, EU220288 and EU232693 (Schell et al. 2008) The biosynthetic gene cassette was assembled in the vector pSG144 as described previously (Schell et al. 2008, ESI), adding sequential genes until the 8 required for sugar biosynthesis were obtained, creating plasmid pAES52.

Plasmid pAES54 was made by ligating the 1 1 ,541 bp Spe\-Nhe\ fragment containing the acf//-ORF4 pactl/lll promotor system and the 8 ang genes was excised from pAES52 with the 5,087 bp Xba\-Spe\ fragment from pGP9, containing an apramycin resistance gene, oriC, oriTfor transfer in streptomycetes and phiBTI integrase with attP site for integrative transformation. (The compatible Nhe\ and Xba\ sites were eliminated during the ligation.) pAES54 was then transformed into S. erythraea SGT2 (Gaisser et al. 2000,

WO2005054265).

Transformation ofpAES54 into S. erythraea SGT2

pAES54 was transferred by conjugation into S. erythraea SGT2 using standard methods. In brief, E. coli ET12567 pUZ8002 was transformed with pAES54 via standard procedures and spread onto 2TY with Apramycin (50 μg/mL), Kanamycin (50 μg/mL), and Chloramphenicol (33 g/mL) selection. This plate was incubated at 37°C overnight. Colonies from this were used to set up fresh liquid 2TY cultures which were incubated at 37°C until late log phase was reached. Cells were harvested, washed, mixed with spores of S. erythraea SGT2, spread onto plates of R6 and incubated at 28°C. After 24 hours, these plates were overlaid with 1 ml_ of sterile water containing 3mg apramycin and 2.5mg nalidixic acid and incubated at 28°C for a further 5-7 days. Exconjugants on this plate were transferred to fresh plates of R6 containing apramycin (100 μg/mL).

Alternative biotransformation strain

Alternatively, BIOT-2945 (Schell et al. 2008) may be used as the biotransformation strain, as this also adds angolosamine to erythronolides. Biotransformation of Azithromycin aglycone to prepare compound 1

Erlenmeyer flasks (250 ml.) containing SV2 medium (40 ml.) and 8 uL thiostrepton (25 mg/mL) were inoculated with 0.2 ml. of spore stock of strain ISOM-4522 and incubated at 30 °C and shaken at 300 rpm with a 2.5 cm throw for 48 hours. SV2 media:

Ingredient Amount

glycerol 15 g

glucose 15 g

soy peptone A3SC 15 g

NaCI 3 g CaCOs g

RO water To final volume of 1 L

Pre-sterilisation pH adjusted to pH 7.0 with 10M HCI

Sterilised by autoclaving @ 121 °C, 30 minutes

Sterile bunged falcon tubes (50 ml.) containing EryPP medium (7 ml.) were prepared and inoculated with culture from seed flask (0.5 ml. per falcon tube) without antibiotics. The falcons were incubated at 30 °C and shaken at 300 rpm with a 2.5 cm throw for 24 hours.

ERYPP medium:

After 24 hours, azithromycin aglycone (0.5 mM in DMSO, 50 uL) was added to each falcon tube and incubation continued at 300 rpm with a 2.5 cm throw for a further 6 days.

Isolation of Compound 1

Whole broth was adjusted to pH 9.5 and extracted twice with one volume of ethyl ace- tate. The organic layers were collected by aspiration following centrifugation (3,500 rpm, 25 minutes). The organic layers were combined and reduced in vacuo to reveal a brown gum that contained compound 1 . This extract was partitioned between ethyl acetate (200 ml) and aqueous ammonium chloride (20 ml of a 50% concentrated solution). After separation, the organic layer was extracted with a further volume (200 ml) of the ammonium chloride aqueous solution. The combined aqueous layers were then adjusted to pH 9.0 with aqueous sodium hydroxide and then extracted twice with one volume equivalent of ethyl acetate. The organic layers were combined and reduced in vacuo to a brown solid. This extract was then applied to a silica column and eluted step wise (in 500 ml lots) with:

Compound 1 was predominantly in F and G. These solvents were combined and reduced in vacuo to yield a brown solid containing compound 1 . This material was then purified by preparative HPLC (C18 Gemini NX column, Phenomenex with 20 mM ammonium acetate and acetonitrile as solvent). Fraction containing the target compound were pooled and taken to dryness followed by desalting on a C18 SPE cartridge.

Example 2 - Preparation of Compound 3_(Known compound - corresponds to compound 17 in Schell et al., 2008)

3a 3

Erythronolide B (3a) can be generated by fermentation of strains of S. erythraea blocked in glycosylation, such as strains and processes described, for example, in US. 3, 127,315 (e.g. NRRL2361 , 2360, 2359 and 2338), Gaisser et al 2000 (e.g. S.ery- thraea DM ABV ACIII.

Erythronolide B (3a) was then fed to a biotransformation strain capable of adding ango- losamine to the 3-hydroxyl (such as NCIMB 42718) and compound 3 was isolated from the fermentation broth by standard methods. xample 3 - Preparation of Compound 4

4a 4

Azithromycin B aglycone (4a) was generated by hydrolysis of the sugars from azithro- mycin B in the same way as for azithromycin A.

Azithromycin B aglycone (4a) was then fed to a biotransformation strain capable of adding angolosamine to the 3-hydroxyl (such as NCIMB 42718) and isolated from the fermentation broth using standard methods. Example 4 - Preparation of Compound 5

5a

Cyclobutyl erythronolide B (5a) was generated using methods described in

WO98/01571. In brief, S.erythraea DM ABV ACIII (Gaisser et al. 2000) was trans- formed with plG1 (Long et al., 2002, WO98/01571 ). Fermentation of the resulting strain with addition of cyclobutene carboxylic acid led to production of Cyclobutyl erythronolide B (5a). This was isolated from fermentation broths using standard methods. Cyclobutyl erythronolide B (5a) was then fed to a biotransformation strain capable of adding angolosamine to the 3-hydroxyl (such as NCIMB 42718) and compound 5 iso- lated from the fermentation broth using standard methods.

Example 5 - Preparation of Compound 6

A methyl group was removed from the aminosugar of compound 3 (see example 2) by adding it to a fermentation of ATCC 31771 and isolating compound 6 from the fermen- tation broth using standard methods.

Example 6 - Preparation of Compound 7

Compound 3 was treated with sodium borohydride in solvent. Following standard reaction work up compound 7 was purified by standard methods.

Example 7 - Preparation of Compound 8

8a 8

14-desmethyl erythronolide B (8a) was generated using methods described in

WO2000/00618. In brief, S.erythraea DM ABV ACIII (Gaisser et al. 2000) was transformed with pPFL43. The resulting strain was fermented using typical methods and compound 8a was isolated using chromatography.

14-desmethyl erythronolide B (8a) was then fed to a biotransformation strain capable of adding angolosamine to the 3-hydroxyl (such as NCIMB 42718) and isolated from the fermentation broth using standard methods.

Example 8 - Preparation of Compound 9

9

14-hydroxy angolosamine erythronolide B (9) was generated by feeding compound 3 (see example 2) to a fermentation of S.rochei ATCC 21250, which adds the hydroxyl group. Compound 9 was then isolated from the fermentation broth using standard methods.

Example 9 - Preparation of Compound 10

6 10

Compound 6 (6.0 mg, 0.01 mmol) was dissolved in dichloromethane (1 mL) and acetal- dehyde (1.0 μί, 0.02 mmol) was added. The reaction was stirred at room temperature and sodium triacetoxyborohydride (2.1 mg, 0.01 mmol) was added. The reaction was stirred for 30 minutes and then quenched by the addition of concentrated aqueous so- dium bicarbonate (25 mL). The aqueous extract was extracted with ethyl acetate (3 x 25 mL). The organic extracts were combined, washed with concentrated brine solution and the solvent was removed in vacuo. The target compound 10 was then purified by preparative HPLC. xample 10 - Preparation of Compound 12

3 11 12

Compound 3 (see example 2) was biotransformed to remove both methyl groups from the aminosugar by adding it to a fermentation of ATCC 31771 and compound 11 was isolated from the fermentation broth using standard methods.

Compound 11 is dissolved in THF and acetaldehyde is added. The reaction is stirred at room temperature and sodium cyanoborohydride is added. The reaction is stirred fur- ther and the reaction is quenched by the addition of aqueous sodium bicarbonate. The aqueous extract is extracted with EtOAc (3 x vol equivalent). The organic extracts are combined, washed with brine and the solvent is removed in vacuo. The target compound 12 is then purified using standard methods. Example 1 1 - Preparation of Compound 14

13 14

Compound 1 (see example 1 ) is biotransformed to remove a methyl group from the aminosugar by adding it to a fermentation of ATCC 31771 and compound 13 is isolated from the fermentation broth using standard methods.

Compound 13 is dissolved in THF and acetaldehyde is added. The reaction is stirred at room temperature and sodium cyanoborohydride is added. The reaction is stirred further and the reaction is quenched by the addition of aqueous sodium bicarbonate. The aqueous extract is extracted with EtOAc (3 x vol equivalent). The organic extracts are combined, washed with brine and the solvent is removed in vacuo. The target pound 14 is then purified using standard methods.

Example 12 - Preparation of Compound 16

1 15 16

Compound 1 (see example 1 ) is biotransformed to remove both methyl groups from the aminosugar by adding it to a fermentation of ATCC 31771 and compound 15 is isolated from the fermentation broth using standard methods. Compound 15 is dissolved in THF and acetaldehyde is added. The reaction is stirred at room temperature and sodium cyanoborohydride is added. The reaction is stirred further and the reaction is quenched by the addition of aqueous sodium bicarbonate. The aqueous extract is extracted with EtOAc (3 x vol equivalent). The organic extracts are combined, washed with brine and the solvent is removed in vacuo. The target com- pound 16 is then purified using standard methods.

Example 13 - Assessment of direct antibacterial activity

The bioactivity of macrolide compounds against 4 strains of common gut bacteria {Escherichia coli, Streptococcus salivarius subsp. salivarius, Lactobacillus casei and Bifidobacterium longum subsp. infantis) and common mammalian skin isolate Micrococcus luteus, was assessed using the Minimum Inhibitory Concentration (MIC) assay. Bacterial strains were purchased from DSMZ (Brunswick, Germany) except M. luteus which was obtained from NCIMB, and stored in 20 % glycerol at -80 °C. Stock solutions (100 % DMSO) of positive controls (azithromycin and erythromycin), and of test compounds 1 and 2 were diluted in broth to working stock concentrations of 256 μg/ml (final assay testing concentration range 128 μg/ml to 0.00391 g/ml). Stock solutions of all other compounds were diluted in broth to working stock concentrations of 128 μg/ml (final assay testing concentration range 64 μg/ml to 0.00195 g/ml).

Bacterial strains were cultivated in appropriate broth in an anaerobic chamber at 37 °C, except for M. luteus which was incubated aerobically at 37 °C. 18 h cultures were diluted in broth to an OD595 of 0.1 and then further diluted 1 :10. In 96-well plates, in duplicate, 200 μΙ working stock of test compound was transferred to well 1 and serially diluted (1 :2) in broth. 100 μΙ bacterial suspension was aliquoted into each well and mixed thoroughly. Appropriate sterility controls were included and plates were incubated in an anaerobic chamber, or aerobically (M. luteus) at 37 °C for 18 h. The MIC was determined to be the concentration of test compound in the first well with no visible growth.

Table 1 :

As can be seen from the data presented in Table 1 , compounds 1 , 3, 4, 5, 6, 7, 8 and 9 show no antibacterial activity against any of the bacterial strains tested, whilst erythromycin and azithromycin show potent activity against a number of the strains. Example 14 - Assessment of immune stimulatory activity

Human peripheral blood mononuclear cells (PBMCs) were purified from healthy donors with Ficoll-Paque density centrifugation. Cells were cultured in complete RPMI-1640 medium (Invitrogen) supplemented with 25mM HEPES, L-glutamine, Sodium pyruvate (Sigma), 10% fetal bovine serum, 100μg/mL penicillin and 100 μg/mL streptomycin (Hyclone). Cells were stimulated for 24h (study 1 -4) or 48 h to 1 week (study 5) in 37 °C, 5% CO2 with increasing concentrations of compound 1 and 2 in tissue culture plates. The cells were removed from the plate, washed in PBS and analysed for expression of cell specific surface markers and MHC class I with flow cytomtery using monoclonal antibodies from BD Pharmingen and a FACS Canto II flow cytometer.

Supernatant IL-10 was measured with a standard sandwich ELISA (all antibodies from BD Biosciences) after 48 hours and 7 days incubation with 2.5 uM of compound 1 and 100 U/mL IL-2 (Miltenyi Biotechnologies) in complete RPMI media, 37 °C, 5% C0 ₂ . Study 1 : After 24h of in vitro stimulation of peripheral blood mononuclear cells (PBMC) with 1 μΜ compound 1 (Figure 8) the activation marker CD69 was upregulated on CD4+ T cells and B cells (Figure 1 ).

Study 2: We also observed upregulation of the molecule MHC class I (HLA-ABC) on T- and B-cells (Figure 2), indicating an effect on antigen presentation of viral antigens.

Study 3: Stimulation of PBMC with compound 1 led to the upregulation of the co-stimulatory molecule CD80 as well as the antigen presenting molecule MHC class II (HLA- DR) on monocytes (Figure 3).

Study 4: Monocytes differentiated into macrophages also upregulated CD80 in response to stimulation by compound 1 (Figure 4).

Study 5: PBMCs stimulated with compound 1 for 48h and 7 days expressed an altered cytokine profile with increased production of the immunosuppressive cytokine IL-10, measured with sandwich ELISA. This indicate an immune inhibitory effect under certain conditions (figure 5).

Study 6: PBMC were stimulated with compound 1 and cultured in RPMI media for 6 days in the presence of IL-2 (Miltenyi Biotechnologies) and Cell Trace Violet Dye (Invi- trogen). Proliferation was measured with flow cytometry. Analysis of the immunological effect of compound 1 revealed an altered cytokine driven proliferation profile of T cells (Figure 6).

Study 7: Virus specific T cell proliferation was also affected by compound 1. PBMCs from cytomegalovirus (CMV) infected donors cultured in the presence of CMV antigen and compound 1 for 6 days displayed an altered phenotype of activated CMV specific CD8+ T cells with an increased expression of IL-7 receptor a (CD127), measured with flow cytometry(Figure 7). CD127 is crucial for T cell homeostasis, differentiation and function, and reduced expression correlates with disease severity in HIV and other chronic viral diseases (Crawley et al. 2012).

As can be seen, compound 1 has a surprising ability to specifically activate and modify an immune response by affecting antigen presentation, co-stimulation and T cell activation and proliferation. In many of these studies, compound 2, another related macrolide erythromycin analogue with altered glycosylation, previously published in Schell et al, 2008 (as compound 20), was included and showed little or no activity in the assays.

Study 8: PBMCs from CMV infected donors cultured in the presence of CMV antigen where either untreated or exposed to compound 1 or compound 2 for 3 days. Exposure to compound 1 induced secretion of high levels of IFN-gamma, whereas antigen culture alone or antigen together with compounds A did not induce IFN-gamma secretion (figure 9).

Study 9: Macrophages from healthy donors where exposed to compounds 1 or 2 for 48 hours. Only macrophages exposed to compound 1 secreted IFN-gamma whereas untreated macrophages and macrophages exposed to compound A did not secrete IFN- gamma (figure 10). Compound 1 is therefore able to induce IFN-gamma secretion in macrophages from healthy donors. Study 10: PBMCs and macrophages where exposed to compounds 1 or 2 for 2 days (fig 1 1 ). Basal expression of RANTES in PBMCs was unaffected by compound 2, whereas compound 1 induced a twofold upregulation of expression. Expression of RANTES was miniscule in macrophages, and compound 1 induced a high expression. Study 1 1 : PBMCs and macrophages where exposed to compounds 1 and 2 for 2 days. PBMCs and macrophages secreted IL-12p70 in response to compound 1 , whereas compound 2 failed to induce secretion over untreated cells (fig. 12).

Study 12: PBMCs, macrophages and CD4+ T cells where exposed to compounds 1 and 2 for 2 days. IL-1 beta secretion was increased by compound 1 in macrophages and slightly in PBMCs while no IL-1 beta was induced in CD4 +T cells (fig. 13). Study 13: Compound 1 was administered i.v. to C57bl/6 mice at 0.165 mg/kg to 5 mg/kg. CD25+ cell abundance was increased in animals receiving the highest dose of 5 mg /kg (fig. 14), as was body weight in the same group (not shown).

Study 14: Compound 1 or 2 was administered i.v. to C57bl/6 mice. 24h later the spleen was removed and MHC class I expression on CD1 1 b+ splenocytes was assessed Compound 1 induced an increase in splenocyte cells with high MHC I expression, whereas no effect was observed in splenocytes from mice injected with compound A.

Example 15 - Assessment of metabolic stability

The metabolic stability of the compounds of the invention was assessed in a standard human microsome stability assay (see general methods). Compounds with longer half- lives would be expected to have longer half-lives following dosing, which can be useful to allow less frequent dosing. Compounds with shorter half-lives could be useful for use as 'soft drugs' where the active entity degrades rapidly once entering the patient's system. The half-life of the compounds assessed in shown in table 2 below:

Table 2

T1/2 (minutes)

Azithromycin 245

Erythromycin 31

Compound 1 108

Compound 3 35

Compound 4 160 i j

Compound 5 83

Compound 6 109

Compound 7 56 j

Compound 8 33

Compound 9 100 j Compound 10 31

Compound 17 151

I Compound 18 25 j

j Compound 19 18

As can be seen, many of the compounds of the invention have increased or decreased metabolic stability as compared to azithromycin, erythromycin and EM703 (e.g. see EP1350510).

Example 16 - Assessment of caco-2 permeability

The permeability of the compounds of the invention was assessed in a standard caco-2 bidirectional permeability assay (see general methods). Compounds with increased permeability would be expected to have better cell penetration and potential for effect, those with improved permeability and/or reduced efflux would be expected to have increased oral bioavailability. The permeability and efflux of the compounds is shown in table 3 below:

Table 3:

Efflux ratio

Azithromycin <0.14 >78

Compound 1 ; 0.32 63

Compound 3 0.27 166

i Compound 4 0.38 49

Compound 5 0.47 81

Compound 8 0.46 56

Compound 10 1.23 26

I Compound 17 0.5 39

Compound 18 9.44 3.5 EM703 <0.15 >108

As can be seen, many of the compounds of the invention have improved cell permeability and/or reduced efflux as compared to azithromycin and EM703 (e.g. see EP1350510).

Example 17- Assessment of TLR2 stimulation

Compounds were tested using a TLR2 reporter assay (see general methods) that measured for stimulation of the TLR2 receptor. Stimulatory effect was measured as an increase in optical density (OD) due to release of secreted alkaline phosphatase (SEAP) and is shown in table 4:

Table 4:

As can be seen, compound 1 stimulated TLR2 at concentrations down to 5uM, com- pound 17 stimulated TLR2 at concentrations down to 10uM, whilst erythromycin A, azithromycin and compounds 2 and 3, related macrolide erythromycin analogues with altered glycosylation, previously published in Schell et al, 2008 (as compounds 17 and 20), showed little or no stimulation at concentrations up to 20uM. Example 18 - Preparation of Compound 17

17a 17

The aglycone 17a was generated from 9-deoxo-8a-aza-8a-methyl-8a-homoerythromy- cin (Wilkening 1993) followed by hydrolysis of the sugars. . 17a was then fed to a biotransformation strain capable of adding angolosamine to the 3-hydroxyl (such as NCIMB 42718) and compound 17 isolated from the fermentation broth using standard methods.

Example 19 - Preparation of Compound 18

8a 18

6-deoxy erythronolide B (6-DEB, 18a) was fed to a biotransformation strain capable of adding angolosamine to the 3-hydroxyl (such as NCIMB 42718) and isolated from the fermentation broth using standard methods. References

Kieser et al. 2000 Practical Streptomyces Genetics, Published by the John Innes Foundation

Crawley et al. The influence of HIV on CD127 expression and its potential implications for I L-7 therapy. Semin Immunol. 2012 Jun;24(3):231-40.

Gaisser et al. Analysis of seven genes from the eryAI-eryK region of the erythromycin biosynthetic gene cluster in Saccharopolyspora erythraea. Mol. Gen. Genet., 1997 Oct;256(3):239-51.

Gaisser et al. A defined system for hybrid macrolide biosynthesis in Saccharopolyspora erythraea Mol. Micro., 2000; 36(2):391-401 Schell et al. Engineered biosynthesis of hybrid macrolide polyketides containing D-an- golosamine and D-mycaminose moieties Org. Biomol. Chem., 2008;6:3315-3327 LeMahieu et al. Glycosidic Cleavage Reactions on Erythromycin A. Preparation of Ery- thronolide A, J. Med. Chem., 1974, 17(9):953-956

Djokic et al. Erythromycin Series. Part 13. Synthesis and Structure Elucidation of 10- Dihydro- 10-deoxo-1 1-methyl-11-azaerythromycin A J. Chem. Res. (S), 1988; 5:152-153 Glansdorp et al. Using Chemical Probes to Investigate the Sub-Inhibitory Effects of Azithromycin, Org. Biolmol. Chem., 2008; 208(6): 4120-4124

Rowe et al. Construction of new vectors for high-level expression in actinomycetes. Gene. 1998 Aug 17;216(1 ):215-23.

Long et al. Engineering specificity of starter unit selection by the erythromycin-produc- ing polyketide synthase. Mol. Microbiol. 2002 Mar;43(5):1215-25.

Wilkening et al. The synthesis of novel 8a-aza-8a-homoerythromycin derivatives via the Beckmann rearrangement of (9Z)-erythromycin A oxime, Bioorg. Med. Chem Lett. 1993, 3 (6), p1287-1292

All references referred to in this application, including patent and patent applications, are incorporated herein by reference to the fullest extent possible.

Specific embodiments of the invention are given in the following list of items.

Item 1

A comp

Formula (I) wherein X is selected from C=0, -NR ₃ CH ₂ -, -CH ₂ NR ₃ -, -NR ₃ (C=0)-, -(C=0)NR ₃ -, C=NOH, and -CH(OH)-, and R ₂ is a sugar of Formula (II) or Formula (III):

Formula (II) Formula (III) wherein Ri is selected from an alkyl, heteroalkyi, cycloalkyi, aryl, and heteroaryl moiety, wherein heteroatoms are selected from O, N, P, and S,

wherein alkyl moiety is selected from C1-C6 alkyl groups that are optionally branched, wherein heteroalkyi moiety is selected from C1-C6 alkyl groups that are optionally branched or substituted and that optionally comprise one or more heteroatoms, wherein cycloalkyi moiety is selected from a C1-C6 cyclic alkyl groups that are optionally substituted and that optionally comprise one or more heteroatoms,

wherein aryl moiety is selected from optionally substituted C6 aromatic rings, wherein heteroaryl moiety is selected from optionally substituted C1-C5 aromatic rings comprising one or more heteroatoms,

wherein substituents, independently, are selected from alkyl, OH , F, CI, N H ₂ , N H-alkyl, N H-acyl, S-alkyl, S-acyl, O-alkyl, and O-acyl,

wherein acyl is selected from C1-C4 optionally branched acyl groups, wherein R3 is selected from H and Me,

wherein R ₄ is selected from H and Me, wherein R _a is selected from H and CR21 R22R23,

wherein R21 , R22, R23, and R5, R6, R7, Rs, R9, and R10, independently, are selected from H, Me, N R11 R12, N0 ₂ , and ORn , wherein R23 together with R ₄ in Formula (II), R ₄ together with R5 in Formula (II), R5 to- gether with R ₇ in Formula (II), and R ₇ together with Rg in Formula (II), independently, may be joined to represent a bond to leave a double bond between the carbon atoms that each group is connected to, wherein R21 together with R22, R5 together with R ₆ , R ₇ together with R ₈ , or R ₉ together with R10 may be replaced with a carbonyl,

wherein Rn and R12, independently, are selected from H and alkyl,

wherein R13 is selected from H, OH, and OCH3,

wherein R14 is selected from H and OH, and wherein one of R5, R6, R7, Rs, R9 or R10 is selected from N R11 R12 and NO2, with the proviso that when Ri is Et, R2 is a sugar of Formula (II), R13 is OH, R14 is H, R _a is H, R ₄ is Me, R5 is H, R ₆ is OH, R ₇ is H, R ₈ is N R11 R12, Rg is H, and R10 is H, X may not be C=0.

Item 2

A compound of item 1

with the proviso that when Ri is Et, R2 is a sugar of Formula (II), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is H, R ₆ is OH, R ₇ is H, R ₈ is NR11 R12, R9 is H, and R10 is H, X may not be C=0.

with the proviso that when Ri is Et, R ₂ is a sugar of Formula (II), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is OH, R ₆ is H, R ₇ is OH, R ₈ is Me, Rg is H, and R10 is H, X may not be C=0.

with the proviso that when Ri is Et, R ₂ is a sugar of Formula (II), R13 is H or OH, R14 is H or OH, R _a is H, R ₄ is Me, R ₅ is OH, R ₆ is H, R ₇ is H, R ₈ is NR11 R12, R9 is H, and R10 is OH, X may not be C=0.

Item 3

A compound according to Item 1 or 2,

wherein R23 together with R4 in Formula (II), R4 together with R5 in Formula (II), R5 to- gether with R ₇ in Formula (II), and R ₇ together with Rg in Formula (II), independently, may be joined to represent a bond to leave a double bond between the carbon atoms that each group is connected to, so that wherein if R23 and R4 are joined to form a double bond, then Formula (II) can be repre- sented b :

wherein if R4 and R5 are joined to form a double bond, then Formula (II) can be repre- sented by:

wherein if R5 and R ₇ are joined to form a double bond, then Formula (II) can be represented

wherein if R ₇ and Rg are joined to form a double bond, then Formula (II) can be represented b

wherein R ₄ together with R5 in Formula (III), R ₄ together with R ₇ in Formula (III), and R ₇ together with Rg in Formula (III), independently, may be joined to represent a bond to leave a double bond between the carbon atoms that each group is connected to, so that wherein if R ₄ and R5 are joined to form a double bond, then Formula (III) can be represented b

wherein if R ₄ and R ₇ are joined to form a double bond, then Formula (III) can be represented by:

wherein if R ₇ and Rg are joined to form a double bond, then Formula (III) can be represented

Item 4

A compound according to Formula (I)

Formula (I) wherein X is selected from C=0, -NR3CH2-, and -CH(OH)-, and R2 is a sugar of mula (II):

Formula (II) wherein Ri is selected from and alkyi or cycloalkyi moiety,

wherein alkyi moiety is selected from C1-C6 alkyi groups that are optionally branched and, independently, optionally hydroxylated,

wherein cycloalkyi moiety is selected from C1-C6 optionally substituted cyclic alkyi groups,

wherein substituents are selected from alkyi and OH, wherein R3 is selected from H and Me,

wherein R ₄ is selected from H and Me, wherein R _a is selected from H and CR21 R22R23,

wherein R21 , R22, R23, and R5, R6, R7, Rs, R9, and R10, independently, are selected from H, Me, N R11 R12, N0 ₂ , and ORn, wherein R23 together with R ₄ in Formula (II), R ₄ together with R5 in Formula (II), R5 together with R ₇ in Formula (II), and R ₇ together with Rg in Formula (II), independently, may be joined to represent a bond to leave a double bond between the carbon atoms that each group is connected to, so that wherein if R23 and R ₄ are joined to form a double bond, then Formula (II) can be repres nted by:

wherein if R ₄ and R5 are joined to form a double bond, then Formula (II) can be repre- sented by:

wherein if R5 and R ₇ are joined to form a double bond, then Formula (II) can be represented by:

wherein if R ₇ and Rg are joined to form a double bond, then Formula (II) can be represented by:

wherein R21 together with R22, R5 together with R6, R7 together with Re, or Rg together with R10 may be replaced with a carbonyl,

wherein Rn and R12, independently, are selected from H and alkyl, wherein R13 is selected from H, OH, and OCH3,

wherein R14 is selected from H and OH, and wherein one of R5, R6, R7, Rs, R9 or R10 is selected from N R11 R12 and NO2, with the proviso that when Ri is Et, R ₂ is a sugar of Formula (II), R13 is OH, R14 is H, R _a is H, R ₄ is Me, R ₅ is H, R ₆ is OH, R ₇ is H, R ₈ is NR11 R12, R9 is H, and R10 is H, X may not be C=0. Item 5

A compound according to any one of the preceding items, wherein R2 is selected from L-daunosamine , L-acosamine, L-ristosamine, D-ristosamine, 4-oxo-L-vancosamine, L- vancosamine, D-forosamine, L-actinosamine, 3-epi-L-vancosamine, L-vicenisamine, L- mycosamine, D-mycosamine, D-3-N-methyl-4-0-methyl-L-ristosamine, D-desosamine, N,N-dimethyl-L-pyrrolosamine, L-megosamine, L-nogalamine, L-rhodosamine , D-an- golosamine, L-kedarosamine, 2'-N-methyl-D-fucosamine, 3-N,N-dimethyl-L-eremosa- mine, D-ravidosamine, 3-N,N-dimethyl-D-mycosamine/D-mycaminose, 3-N-acetyl-D- ravidosamine, 4-O-acetyl-D-ravidosamine, 3-N-acetyl-4-0-acetyl-D-ravidosamine, D- glucosamine, N-acetyl-D-glucosamine, L-desosamine, D-amosamine, D-viosamine, L- avidinosamine, D-gulosamine, D-allosamine, and L-sibirosamine.

Item 6

A compound according to any one of the preceding items, wherein R ₂ is selected from D-angolosamine, N-desmethyl D-angolosamine, N-didesmethyl D-angolosamine, N- desmethyl N-ethyl D-angolosamine, and N-didesmethyl N-diethyl D-angolosamine.

Item 7

A compound according to any one of the preceding items, wherein R2 is a sugar according to Formula (II).

Item 8 A compound according to any one of the preceding items, wherein R2 is a sugar according to formula II wherein R _a is H, R ₄ is Me, R5 is H, R6 is OH, R ₇ is H, Re is NRn Item 9

A compound according to any one of the preceding items, wherein Rn is selected from H, Me, and Et, and R12 is selected from H, Me, and Et.

Item 10

A compound according to any one of the preceding items, wherein Rn is Et and R12 is Et.

Item 1 1

A compound according to any one of items 1-87, wherein Rn is Me and R12 is Et. Item 12

A compound according to any one of the preceding items, wherein X is selected from C=0, -N R3CH2- and -CH(OH)-

Item 13

A compound according to any one of the preceding items, wherein Ri is selected from Me, Et, and cycloalkyl.

Item 14

A compound according to any one of the preceding items, wherein Ri is selected from Me and Et.

Item 15

A compound according to any one of the preceding items selected from:

Item 16

A compound as defined in any one of the preceding items for use in medicine.

Item 17

A compound as defined in any one of items 1 -15 for use in the treatment of viral dis ^¬ ease.

Item 18

A compound as defined in any one of items 1-15 for use in the treatment of HIV/AIDS. Item 19

A method for preparing a compound as defined in any one of items 1 -15, the method comprising addition of an aglycone with Formula (IV)

to a culture of a biotransformation strain which glycosylates at the 3-hydroxyl position.

Item 20

A method according to item 19, wherein the biotransformation strain expresses glyco- syltransferases with >70% homology to AngMII and AngMIII

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