2. The Prior Art Some 1-aryl-3- (2-chloroethyl) urea derivatives (hereinafter referred to as"CEUs") are known from US Patents 5,530,026 and 5,750,547 to the same assignee as the present application. More specifically, compounds of the following formula are known: wherein R refers to various substituents on the phenyl ring.

It is known that CEUs display an affinity towards cancer cells, permeate the cell wall and provide a mild alkylating effect on cell components thereby killing the offendingcell.

An object of the invention is to provide novel CEU derivatives having significantly superior antineoplastic activity over known CEUs while maintaining low systemic toxicity, mutagenicity and side-effects.

SUMMARY OF THE INVENTION It has now been found, against expectations and documented precedents that specific substitutions on the first carbon atom of the 2-chloroethyl group of the CEU molecule provides a significant improvement on the anticancer effect of the resulting CEU.

Moreover, it has been found that yet unknown substitutions on the phenyl ring render the resulting CEU molecule even more efficient at targeting specific regions of cancerous cells thereby improving their specificity toward various cellular proteins key to cell survival.

More specifically, this invention provides a novel class of CEU derivatives. This novel class of CEU may be expressed by the following formula: wherein R, is lower alkyl (1 to 6 carbon atoms) or cycloalkyl (3 to 7 carbon atoms) or lower alkoxy or hydroxy alkyl (1 to 6 carbon atoms) lower halide, lower di-halide or lower tri-halide (Br, I, Cl, F) (1 to 6 carbon atoms) R2 is H or lower alkyl (1 to 6 carbon atoms) or cycloalkyl (3 to 7 carbon atoms) or lower alkoxy or hydroxy alkyl (1 to 6 carbon atoms)

lower halide, lower di-halide or lower tri-halide (Br, I, Cl, F) (1 to 6 carbon atoms) R, and R2 could also be part of cyclic structures expressed by the formula: examples: R3 and R4 are as defined in Rs or halide, dihalide or trihalide (e. g. CF3) lower dialkyl (1 to 8 carbon atoms) in R3 and R4, (the number of carbon atoms present is not necessarily identical ("asymetric molecules")) or alicyclic groups of the following structures wherein n = 2 to 8 carbon atoms, The alicyclic ring could also be substituted by one or more substituting groups comprising groups as described for R, R3 and R4can also be polycyclic rings bearing not more than three rings such as dihydrophenanthrene, anthracene, phenanthrene, fluorenyl, etc., examples:

wherein the rings other than the ring bearing the substituted 2-chloroethylamino moiety can be substituted by one or more groups as defined in R5.

R5 is H or lower alkyl (1 to 7 carbon atoms) or lower alkoxy or hydroxy alkyl, amino alkyl, thio alkyl (1 to 7 carbon atoms) or S-lower alkyl N-lower alkyl N,N-dilower alkyl lower cyanoalkyl (1 to 7 carbon atoms) cycloalkyl (3 to 7 carbons atoms) lower haloalkyls (Br, I, Cl, F) (1 to 7 carbon atoms) lower sulfoxides (1 to 7 carbon atoms) Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that this detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Before describing the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the preferred embodiments and examples described herein. The invention is capable of other embodiments and of being practised in various ways. It is also to be understood that the phraseology or terminology used herein is for the purpose of description and not limitation.

MODIFICATION OF THE 2-CHLROETHYL MOIETY (R, and R2 groups) Experiments to assess the biopharmaceutical properties of known 1-aryl-3- (2- chloroethyl) ureas (CEUs) have unexpectedly revealed that certain cell enzymes such as cytochromes P450 1A2 and 2E1 were oxidizing CEUs therefore metabolizing them to inert molecules and depriving them of anticancer effect.

The metabolization mechanism was again unexpectedly found to operate on the first carbon atom on the chloro-2-ethyl moiety adjacent to the urea moiety. i i \/N Ri i R1 R4=/C1 '2 fui2-chloroethyl moeity i aryl moeity urea moeity For example, in the case of a 4-tert-butyl CEU (tBCEU), metabolization occurred along the following pathway: 0 ci H H several other metabolites 4-ter-butylCEU (tBCEU) oxydation OHC-CHZCI + 0 oxidation Yl H CI/\ i i/ OH H H OH H H Metabolite I Main metabolite glucuronidation I' glucuronidation ' 0 u-. COOH \-/i'.,-. U H COOHglucuronide de la tBCEU- ( Metabolite H H H H H OH H OH H OH

Surprisingly this has revealed a metabolic weak spot at the first carbon atom of the 2-chloro-ethyl moiety of the CEUs. Thus, the present invention generally aims at providing protecting groups on this first carbon atom and at providing novel CEU derivatives having potent antineoplastic activity.

More specifically, the protection of the weak carbon atom from metabolization was achieved by substituting the hydrogen atoms with groups such as lower alkyl groups such as methyl, ethyl and propyl.

MODIFICATION OF THE R3, R4 AND R5 MOITIES Furthermore, it was surprisingly discovered that certain modifications of substituents on the aryl moiety dramatically improved the specificity of the resulting CEU derivatives toward various cellular proteins key to cell survival. Thus, the following compounds were developed and are expressed by the general formula:

wherein R, is lower alkyl (1 to 6 carbon atoms) or cycloalkyl (3 to 7 carbon atoms) or lower alkoxy or hydroxy alkyl (1 to 6 carbon atoms) lower halide, lower di-halide or lower tri-halide (Br, I, Cl, F) (1 to 6 carbon atoms) R2 is H or lower alkyl (1 to 6 carbon atoms) or cycloalkyl (3 to 7 carbon atoms) or lower alkoxy or hydroxy alkyl (1 to 6 carbon atoms) lower halide, lower di-halide or lower tri-halide (Br, I, Cl, F) (1 to 6 carbon atoms) R, and R2 can be part of cyclic structures expressed by the formula: Such as:

wherein the arrows on the molecule on the right hand side indicate the position where the molecule can be substituted by the chlorine atom; R3 and R4 are as defined in R, or halide, dihalide or trihalide (e. g. CF3) lower dialkyl (1 to 8 carbon atoms) in R3 and R4, (the number of carbon atoms present is not necessarily identical ("asymetric molecules")) or alicyclic groups of the following structures wherein n = 2 to 8 carbon atoms,

R3 and R4 can also be polycyclic rings bearing not more than three rings such as dihydrophenanthrene, dihydroanthracene, anthracene, phenanthrene, fluorenyl, etc., examples:

wherein the rings other than the ring bearing the substituted 2-chloroethylamino moiety can be substituted by one or more groups as defined in Rs R5 is H or lower alkyl (1 to 7 carbon atoms) or lower alkoxy or hydroxy alkyl, amino alkyl, thio alkyl (1 to 7 carbon atoms) or S-loweralkyl N-lower alkyl N,N-dilower alkyl lower cyanoalkyl (1 to 7 carbon atoms) cycloalkyl (3 to 7 carbons atoms) lower haloalkyls (Br, I, Cl, F) (1 to 7 carbon atoms) lower sulfoxides (1 to 7 carbon atoms) PREPARATION OF CEU DERIVATIVES The compounds of the present invention are easily prepared in good yields without concomitant polymerization or decomposition. The compounds are also easily purified by usual techniques such as crystallization or liquid chromatography. Furthermore, the compounds exhibit an extended shelf life without decomposition in air.

The type and level of activity for a given dosage of each compound can be conventionally determined by routine experimentation using well-known pharmacological protocols.

The compounds of the present invention appear to kill cancer tumor cells by alkylation of their ß-tubulin on a specific cysteine residue (Cyst-239) and also by other mechanisms under investigation. The molecular structure of ß-tubulin has been highly conserved throughout evolution and is therefore present many mammalian cells. Consequently, the compounds of the invention are indicated for: wideranging anticancer agents, transdermic for pre-surgical treatment of melanomas and systemic for other cancers.

Prodrugs of the compounds of the present invention may also be easily prepared. As an example of prodrugs of the compounds of the present invention, the sulfone and sulfoxide derivatives of alkylthio substituents is immediately contemplated by skilled worker in this art. The sulfone and sulfoxide derivatives while not generally active will be activated once administered to a patient. The activation will occur when the prodrug is reduced to yield the corresponding alkylthio, an active compound. The following synthesis flowsheet illustrates one route of preparation of CEU derivatives of the present invention. P3 f?!? P3, 4-dimethyl R3 p R4 NH2 + 0 0 aininol) yridineR NHA C Z l2 Aniline Di-tert-butyl dicarbonate OH | or + OH Or H nez R Ri R or S isomer R or S isomer Ri R N R N RUZ OH or -\//-N H H H H R or S isomer R or S isomer Triphenylphosphine CH2CI2 and CCI4 R3 0 R, 3 0 R, 4 IN 1 R2 Cl or I I H H H H R or S isomer R or S isomer

It is important to note that the preparation of CEU derivatives of the present invention has led to the formation of R and S isomers which (in some cases) exhibit significant differences in cytotoxic activities (see Tables I and 11 below).

EXAMPLES PREPARATION OF N- (4-ALKYLPHENYL)-N'- (1-ALKYL-2-HYDROXY) ETHYLUREAS These compounds were prepared following the general synthetic route illustrated above.

To a stirred solution of di-tert-butyldicarbonate (3.9 mmol) and 4- dimethylaminopyridine (0.4 mmol) in anhydrous dichloromethane (20 mL) was added dropwise the relevant aniline (also 2-aminofluorenyl, 2-aminonaphthyl, etc. derivatives) (3.7 mmol). The reaction mixture was stirred for 30 min at room temperature and the required (R) or (S) aminoalcohol was added dropwise. The mixture was stirred overnight at room temperature. The solvent was evaporated under vacuum and the crude product was purified by flash chromatography on silica gel (dichloromethane/ethyl acetate, 20/80) to yield the hydroxyurea as a colorless solid.

HALOGENATION OF N- (4-ALKYLPHENYL)-N'- (1-ALKYL-2-HYDROXY) ETHYLUREAS INTO N- (4-ALKYLPHENYL)-N'- (1-ALKYL-2-CHLORO) ETHYLUREAS A solution of the relevant hydroxyurea (2.4 mmol) and triphenylphosphine (3.7 mmol) in a mixture of dichloromethane and carbon tetrachloride (20: 6) was stirred overnight at room temperature. The solvent was evaporated under reduced pressure and the crude product purified by flash chromatography on silica gel (ethylether/petroleum ether, 50/50) to give the chloroethylurea as a white solid.

Of import, the R, or/and R2 substituted CEUs may also be prepared by several synthetic routes. One skilled in the art will quickly appreciate this.

EXAMPLE 1: EVALUATION OF CYTOTOXIC ACTIVITY Compounds prepared in accordance with the method outlined above were synthesized and evaluated for cytotoxic activity. The molecular structure of each one of them was verified by IR, NMR and mass spectroscopy.

Table I below, provides the evaluation of the in-vitro cytotoxic activities of various compounds prepared in accordance with the synthesis illustrated above and in which R3 and Rs were H.

The conventional evaluation method proposed by the American National Cancer Institute was used. The method measures effectiveness of an anti-cancer drug based on ICso which symbolizes the drug concentration in, uM at which the drug achieves the inhibition of proliferation of a given line of cancer cells by a factor of one half when compared to the normal proliferation of the same line of cancer cells in the same growth media Cytotoxicity Assay: CEU were tested on several cell lines including human non-hormone-dependant breast cancer cells (MDA-MB-231), and mouse leukemia (L1210). MDA-MB- 231. These cell lines were obtained from the American Type Culture Collection (Bethesda, MD, USA). Cytotoxicity of CEU derivatives was tested and compared to the effect of chlorambucil and carmustine.

Tumor cells were grown in RPMI-1640 medium supplemented with 10% fetal calf serum, 2 mM glutamine and 64 U/mL of gentamycin. Cells were routinely passaged at 90% confluence.

Five thousand cells (100, ul) were seeded in 96 well's plate and incubated for one day at 37°C under a humidified atmosphere, in presence of 5% CO2.

Subsequently, 100 NI of fresh medium containing CEU to obtain final concentrations ranging from 1-to 200, hum were added to the cultures. CEU were dissolve in dimethyl sulfoxide (DMSO; Aldrich Chemicals Company Inc., Milwaukee, WI) which is maintained at 0.5 % (v/v). Cells were incubated for four to five days in the presence of drugs.

Cell's survival was evaluated by colorimetric assay using MTT, according to a modification of the procedure reported by Carmichael and coll. [Carmichael J,

De Graff WG, Gazdar AF, Minna ID, Mitchell JB (1987) Cancer Res 47,936- 942]. Briefly, the culture media was replace by 50, ul of a solution containing MTT (1.0 mg/ml in PBS: RPMI-1640, (1: 4)). The MTT is reduced by mitochondrial dehydrogenase to form MTT-formazan. After two hours of incubation at 37°C, the wells were washed with 200, ul of saline and 100, uL of DMSO containing 0.5% v/v of a glycine solution 0.1 M at pH 11 (NaOH) were added to dissolve the precipitate. The plates were then shaken for 15 minutes and the absorbance read at 570 nm with a Behring Elisa Procesor II (Behring, Marburg, Germany).

The evaluation was performed on two typical cancer cell lines namely, L1210 (mouse leukemia cells) and MDA-MB-231 (human breast cancer cells). A comparison with conventional anti-cancer drugs chlorambucil and carmustine is provided to illustrate the effectiveness of the compounds of the present invention.

TABLE I IN-VITRO CYTOTOXIC ACTIVITY IC50 IC50 R, R2 R3 R4 L1210 MDA-MB- (µM) 231 (µM) 1. 3 3. 1 H H H sec-butyl 2.0 4. 5 R-methyl H H sec-butyl 19.6 72. 4 H S-methyl H H sec-butyl 17 56 R-ethyl H H sec-butyl 20.7 67 H S-ethyl H sec-butyl 14 32 R and S-propyl H H sec-butyl 15 Nd Methyl Methyl H sec-butyl 2. 6 6. 2 H H H tert-butyl 2.3 6. 1 R-methyl H H tert-butyl 20 74 H S-methyl H tert-butyl 19 55 R-ethyl H H tert-butyl 16 67 H S-ethyl H tert-butyl IC50 IC50 R, R2 R3 R4 L1210 MDA-MB- (Jim) 231 (« M) 23 52 R and S-propyl H H tert-butyl > 100 > 100 Methyl Methyl H tert-butyl 1. 2 2. 5 H H H iso-propyl R-methylHHiso-propyl0.51.7 29.7 > 100 H S-methyl H iso-propyl 16 49 R-ethyl H H iso-propyl HS-ethylHiso-propyl2285 8.7 24 R and S-propyl H H iso-propyl 80 > 100 Methyl Methyl H iso-propyl 4.5 6. 8 Carmustine 2.6 81 Chlorambucil

The above experiments show that the R isomer on the R, group provided greater activity than the S isomer.

EXAMPLE 2 In a related set of experiments, the tert-butyl group of R4 was replace with iodine to yield 4-iodoCEUs (bioisosteric form of the tert-butyl group). R5 remained H. Table II below evaluates the cytotoxicity of such molecules and the effect of substitution on the 2-chloroethylamino moiety. During the experiments, ICsowas recorded against cancer cell lines L1210 and K562 (mouse leukemia cells).

TABLE II IN-VITRO CYTOTOXIC ACTIVITY R1R2R3R4IC50IC50 L1210 K562 (Jim) (pM) 5.4 3.8 H H H I 1.6 1.1 R-methyl H H I 10 S-methylHIH

This shows that the R isomer of the 4-iodoCEUs (bioisosteric form of the tert- butyl group) following a substitution on the 2-chloroethylamino moiety results in a very active drug.

EXAMPLE 3 In another related set of experiments wherein R, is H or CH3, and R2 is CH3, the effect on substitutions on the phenyl ring were observe. It is theorized that theses substitutions assist in the positioning and selectivity of the compounds towards key intracellular proteins.

The results of in-vitro tests are reported in Table III below.

TABLEII I IN-VITRO CYTOTOXIC ACTIVITY R3 R4 (µM)IC50(µM)IC50 (MDA-MB-231) L1210 H Methyl H 24. 1 16. 4 Methyl H H 60 27 Methyl Methyl H 7. 2 3. 8 Methyl H Methyl 20 8. 8

From these observations, the R and S alkyl CEU deriving from 3,4 dimethylCEUs are particularly effective anti-cancer agents.

EXAMPLE 4

In another experiment the following polycyclic molecules were prepared: wherein R, is H or CH3, and R, is CH3 In-vitro cytotoxic activities are reported in Table IV below.

TABLE IV IN-VITRO CYTOTOXIC ACTIVITY R2IC50(µM)IC50(µM)DRUGR1 CHO MDA-MB-231 H9.910.3CEU-1H CEU-1 R-methyl H 9. 8 9. 5 CEU-1 S-methyl 78 > 100 CEU-2 H H 9. 3 9. 0 CEU-2 R-methyl H 16. 3 13 CEU-2 H S-methyl 16. 1 50 CEU-3 H H 7. 2 6. 1 H3.13.2CEU-3R-methyl CEU-3 H S-methyl 63 > 100

These results show that the modification of the carbon 1'of CEU led to R and S isomers of CEU. R isomers are in most cases more cytotoxic than the unsubstituted CEU. Furthermore, R isomers are in most cases several fold more potent than the S isomers. This might be due to better specificity toward the protein (s) they alkylate.

EXAMPLE 5 The following compounds were successfully tested for cytotoxic acitivity. R1 R2 (µM)IC50(µM)IC50(µM)IC50(µM)IC50(µM)IC50 CHO HT-29 K562 MDA-MB-231 H R-ethyl tert-butyl 44 25 32. 2 55 H R-ethyl iso-propyl 48 30 18 49 H R-ethyl sec-butyl 38 27 23 56 H R-propyl tert-butyl 60 27 21 52 H R-propyl iso-propyl 21. 3 17 6 24 H R-propyl sec-butyl 29 16. 4 11 32 CHO= Chinese Hamster Ovary

MDA-MB-231 Hormone-independant breast cancer HT-29 human colon carcinoma K562 human leukemia EXAMPLES 6-15 Based on the formula of the compounds of the present invention as shown above, specific molecules were synthesized and later tested for citotoxic activity.

EXAMPLE 6 Ri R2 R3IR4 I H Methyl (S configuration) H n-hexyl Flash chromatography: ether: petrol ether = 1: 1 Rf = 0.31 (ether: petrol ether = 1: 1) 'H-NMR (CDC ! j): 7.17 (d, 2H, H-C2 and H-C6, J = 8. 4 Hz), 7.11 (d, 2H, H-C3 <BR> <BR> and H-C5, J = 8.4 Hz), 4.27 (m, 1 H, CH (CH3) CH2CI), 3.72 (dd, 1H, CH2Cl, J = 4.3 and J = 11.0 Hz), 3.57 (dd, 1H, CH2Cl, J = 3.4 and J = 11.0 Hz), 2.55 (t, 2H, CH3 (CH2) 4CH2), 1.53 (m, 2H, CH3 (CH2) 3CH2CH2), 1.23 (d, 3H, CH(CH3)CH2Cl, J = 6.9 Hz), 1.18-1.43 (m, 6H, CH3(CH2ç3 CH2CH2), 0.87 (t, 3H, CH3 (CH2) s) EXAMPLE 7 R, R2 R3 R4 H Hn-hexyl(Rconfiguration)

Flash chromatography: ether: petrol ether = 2: 3 Rf = 0.29 (ether: petrol ether = 2: 3) 'H-NMR (CDCI3): 7.16 (d, 2H, H-C2 and H-C6, J = 8.5 Hz), 7.07 (d, 2H, H-C3 and H-C5, J = 8.5 Hz), 5.33 (br s, 1 H, NH), 4.23 (m, 1 H, CH (CH3) CH2CI), 3.65 (dd, 1 H, CH2Cl, J = 4.5 and J = 11.0 Hz), 3.53 (dd, 1 H, CH2Cl, J = 3.5 and J = 11.0 Hz), 2.52 (t, 2H, CH3 (CH2)4CH2, J = 7. 5 Hz), 1.50-1.60 (m, 2H, CH3 (CH2) 3CH2CH2), 1.28 (m, 6H, CH3 (CH2) 3CH2CH2), 1.19 (d, 3H, CH (CH3) CH2Cl, J = 6.7 Hz), 0.87 (t, 3H, CH3(CH2)5, J = 6.5 Hz).

EXAMPLE 8 R, R2 R3 R4 H Methyl H Cyclohexyl (R configuration) Flash chromatography: ether: petrol ether = 1: 1 'H-NMR (CDC13): 7.16 (d, 2H, H-C2 and H-C6, J = 8.4 Hz), 7.11 (d, 2H, H-C3 and H-C5, J = 8.4 Hz), 4.24 (m, 1 H, CH (CH3) CH2Cl), 3.66 (dd, 1H, CH2Cl, J = 4.2 and J = 11.0 Hz), 3.54 (dd, 1 H, CH2Cl, J = 3. 4 and J = 11.0 Hz), 2.43 (m, 1 H, CH-Ph), 1.70-1.90 (m, 6H, H-cyclohexyl), 1.35-1.45 (m, 4H, H-cyclohexyl), 1.20 (d, 3H, CH (CH3) CH2CI, J = 6.7 Hz).

EXAMPLE 9 Ri R2 R3 R4 H Methyl H cyclohexyl (S configuration)

Flash chromatography: ether: petrol ether = 1: 1 Rf = 0.24 (ether: petrol ether = 1: 1) 'H-NMR (CDCI3): 7.18 (d, 2H, H-C2 and H-C6, J = 8.7 Hz), 7.14 (d, 2H, H-C3 and H-C5, J = 8.7 Hz), 4.27 (m, 1 H, CH (CH3) CH2CI), 3.71 (dd, 1H, CH2Cl, J = 4.4 and J = 11.0 Hz), 3.56 (dd, 1 H, CH2Cl, J = 3.2 and J = 11.0 Hz), 2.45 (m, 1 H, CH-Ph), 1.70-1.85 (m, 6H, H-cyclohexyl), 1.36 (m, 4H, H-cyclohexyl), 1.23 (d, 3H, CH (CH3) CH2Cl, J = 6.8 Hz).

EXAMPLE 10 R, R2 R3 R4 H-ethyl H n-hexyl (R configuration) Flash chromatography: ether: petrol ether = 10: 11

Rf = 0.38 (ether: petrol ether = 1: 1) 'H-NMR (CDCI3): 7.17 (d, 2H, H-C2 and H-C6, J = 8.4 Hz), 7.08 (d, 2H, H-C3 and H-C5, J = 8.4 Hz), 5.24 (br s, 1 H, NH), 4.02 (m, 1 H, CH (CH2CH3)CH2Cl), 3.69 (dd, 1 H, CH2CI, J = 4.0 and 11.0 Hz), 3.60 (dd, 1H, CH2Cl, J = 3. 3 and 11.0 Hz), 2.53 (t, 2H, CH2Ph, J = 7. 8 Hz), 1.56 (m, 4H, CH3 (CH2) 3CH2CH2 and CH (CH2CH3) CH2CI), 1.28 (m, 6H, CH3 (CH2) 3CH2CH2), 0.89 (2t, 6H, CH3 (CH2) 5 and CH (CH2CH3)CH2Cl, J = 6. 5 and 7.4 Hz).

EXAMPLE 11 R, R2 R3 R4 H-ethyl H n-hexyl (R configuration)

Flash chromatography: ether: petrol ether = 35: 65 Rf = 0.28 (ether: petrol ether = 2: 3) 'H-NMR (CDCl3) : 7.16 (d, 2H, H-C2 and H-C6, J = 8.2 Hz), 7.06 (d, 2H, H-C3 and H-C5, J = 8.2 Hz), 5.41 (br s, 1H, NH), 4.02 (m, 1H, CH(CH2CH3)CH2Cl), 3.67 (dd, 1H, CH2Cl, J = 4.2 and 11.0 Hz), 3.58 (dd, 1H, CH2Cl, J = 3.5 and 11.0 Hz), 2.52 (t, 2H, CH2Ph, J = 7.7 Hz), 1.55 (m, 4H, CH3 (CH2) 3CH2CH2 and CH (CH2CH3)CH2Cl), 1.28 (m, 6H, CH3 (CH2) 3CH2CH2), 0.89 (2t, 6H, CH3 (CH2) s and CH(CH2CH3)CH2Cl, J = 6.6 and 7.5 Hz).

EXAMPLE 12 R, R2 R3 R4 H Ethyl H cyclohexyl (Sconfiguration)

Flash chromatography: ether: petrol ether = 10: 11 Rf = 0.38 (ether: petrol ether = 1: 1) 'H-NMR (CDCI3): 7.18 (d, 2H, H-C2 and H-C6, J = 8.7 Hz), 7.14 (d, 2H, H-C3 and H-C5, J = 8.7 Hz), 4.04 (m, 1 H, CH (CH3) CH2Cl), 3.73 (dd, 1 H, CH2CI, _ 4.0 and J = 11.2 Hz), 3.63 (dd, 1 H, CH2CI, J = 3.2 and J = 11.2 Hz), 2.46 (m, 1 H, CH-Ph), 1.70-1.85 (m, 4H, H-cyclohexyl), 1.58 (m, 2H, CH CH2CH3CH2Cl), 1.18-1.45 (m, 6H, H-cyclohexyl), 0.93 (t, 3H, CH (CH2CH3)CH2Cl, J = 7.4 Hz).

EXAMPLE 13 R, R2 R3 R4 H Ethyl H cyclohexyl (R configuration)

Flash chromatography: ether: petrol ether = 1: 1 Rf = 0.35 (ether: petrol ether = 1: 1)

'H-NMR (CDCl3) : 7.18 (d, 2H, H-C2 and C6, J = 8. 5 Hz), 7.13 (d, 2H, H-C3 and H-C5, J = 8.5 Hz), 4.03 (m, 1 H, CH (CH3) CH2Cl), 3.72 (dd, 1 H, CH2CI, = 3.9 and J = 11.1 Hz), 3.64 (dd, 1 H, CH2CI, J = 3.4 and J = 11.1 Hz), 2.45 (m, 1 H, CH-Ph), 1.65-1.95 (m, 4H, H-cyclohexyl), 1.56 (m, 2H, CH CH2CH3)CH2Cl), 1.20-1.40 (m, 6H, H-cyclohexyl), 0.93 (t, 3H, CH (CH2CH3) CH2CI,J = 7.4 Hz).

EXAMPLE 14 R, R2 R3 R4 H Propyl H n-hexyl (mixture of R and S isomers)

Flash chromatography: ether: petrol ether = 2: 3 Rf = 0.31 (ether: petrol ether = 2: 3) 1H-NMR (CDCl30 : 7.17 (d, 2H, H-C2 et C6, J = 8. 2 Hz), 7.04 (d, 2H, H-C3 et C5, J = 8.2 Hz), 4.05 (m, 1 H, CH (CH2CH2CH3CH2Cl), 3.64 (dd, 1 H, CH2Cl, J = 4.3 et J = 11 Hz), 3.54 (dd, 1H, CH2CI, J = 3.7 et J = 11 Hz), 2.51 (t, 2H, CH3(CH2)4CH2, J = 7. 7 Hz), 1.25-1.60 (m, 12H, CH3 (CH2) 4CH2 and (t,3H,CH(CH2CH2CH3CH2Cl,J=7.2Hz).CH(CH2CH2CH3)CH2Cl),0.88 EXAMPLE 15 R, R2 R3 R4 H Propyl H cyclohexyl (mixture of R and S isomers)

'H-NMR (CDC13): 7.18 (d, 2H, H-C2 et C6, J = 8.7 Hz), 7.13 (d, 2H, H-C3 et C5, J = 8.7 Hz), 4.13 (m, 1 H, CH (CH2CH2CH3) CH2CI), 3.73 (dd, 1 H, CH2Cl, J = 4.1 et J = 11.1 Hz), 3.59 (dd, 1 H, CH2CI, J = 3.5 et J = 11.1 Hz), 2.45 (m, 1 H, CH-Ph), 1.20-2.00 (m, 14H, CH2-cyclohexyl et CH (CH2CH2CH3) CH2CI), 0. 91 (t, 3H, CH (CH2CH2CH3) CH2CI, J = 7.1 Hz).

EXAMPLE 16: EVALUATION OF CYTOTOXYCITY ACTIVITY: Cell culture. Tumor cell lines (B16-F0, Caco-2, DU-145, HT-29, MDA-MB-231 and other cell lines described so far in the patent application) were obtained from the American Type Culture Collection (ATCC HTB-26; Bethesda, MD).

Cells were grown in RPMI 1640 medium supplemented with 10% fetal bovine serum (Hyclone, Road Logan, Utah) and were cultured in a humidified atmosphere at 37 °C in 5% C02.

Drugs: All drugs were dissolve in DMSO and the final concentration of DMSO in the culture medium was maintained at 0.5 % (v/v).

Cytotoxiciy assays. At day-1, tumor cells in suspension in 100 µl were plated in microtiter plates (96 wells). On day-0, tumor cells were treated by addition of escalating concentrations of the drug (100, solution). On that day, the number of living cells was determined in wells that were untreated. This was performed in order to be able to evaluate the toxic concentration of the drug needed to kill

50% of the cellular population present at the beginning of the experiments. This value is represented by C50 in the table. At day-3, the number of living cells is determined using either MTT or resazurin assays. Growth inhibition activity of these compounds was expressed as the concentration of CEU inhibiting cell growth by 50% Gso in the following table The MTT assay was as described above in Example 1. The Resazurin assay was performed as follows: Aspirate the supernatant (cell suspension: centrifuge first) Add 100, uL NaCI 0.9% (saline) Aspirate the supernatant (cell suspension: centrifuge first) Add 50, uL RZ (resazurin 125, ug/ml/PBS: RPMI without FBS; 1: 4) Incubate at 37°C Collect fluorescence data at different time.

FILTER EM EM CENTER 590 590 TABLE V IN-VITRO CYTOTOXIC ACTIVITY Cell line R3R4C50(µM)G50(µM)C50/GR2 HT-29 H Methyl H n-hexyl 12.8 5.1 2.51 (R isomer DU-145 idem idem Idem Idem 11.8 6.3 1.86 MDA-MB-idem idem Idem Idem 31.9 11.7 2.72 231 Caco-2 idem idem Idem idem 21.1 12.6 1.68 B 16-FO idem idem idem Idem 18.2 16.3 1.12 DU-145 H Methyl H n-hexyl 39.5 18.9 2.09 (S isomer) B16-FO idem idem idem Idem 31.3 26.3 1.19 MDA-MB-idem idem idem Idem 43.3 31.5 1.37 231 HT-29 idem idem idem Idem 44.5 32.3 1.38 Caco-2 idem idem idem Idem 44.2 35.8 1.23 HT-29 H propyl H n-hexyl 20.3 10.7 1.90 (racemic R1R2R3R4C50(µM)G50(µM)C50/GCellline mixture) DU-145 idem idem idem Idem 19.6 10.9 1.80 Caco-2 idem idem idem Idem 21.1 12.7 1.34 B16-FO idem idem idem Idem 21.3 15.8 1.71 MDA-MB-idem idem idem Idem 32.3 18.9 1.71 231 DU-145 H ethyl H n-hexyl 27.2 7.4 3.68 (S isomer) Caco-2 idem idem idem Idem 13.7 10.2 1.35 MDA-MB-idem idem idem Idem 40.6 18 231 B16-F0 idem idem idem Idem 24. 9 18.8 1.33 HT-29 idem idem idem Idem 36.8 20.8 1.77 DU-145 H ethyl H n-hexyl 15.8 4.6 3.46 (R isomer) Caco-2 idem idem idem idem 7. 5 i. 45 HT-29 idem idem idem idem 20.8 13.1 1.58 B 16-FO idem idem idem idem 18.3 14.1 1.29 MDA-MB-idem idem idem idem 30.1 15.1 1.99 231 DU-145 H methyl H cyclohe 27.6 7.8 3.52 (S isomer) xy ! Caco-2 idem idem idem idem 14.7 8.6 1.70 B 16-Fo idem idem idem idem 17.4 15.4 1.13 HT-29 idem idem idem idem 28.1 19 1.48 MDA-MB-idem idem idem idem 42.9 27.5 1.56 231 DU-145 H methyl H cyclohe 25.2 8.6 2.94 (R xyl isomer) Caco-2 idem idem idem idem 20.3 15.4 1.32 HT-29 idem idem idem idem 23.9 17.1 1.40 B16-FO idem idem idem idem 22.1 21.8 1.01 MDA-MB-idem idem idem idem 42.3 27.6 1.53 231 DU-145 H ethyl H cyclohe 22.2 7.3 3.04 (S isomer) xyl Caco-2 idem idem idem idem 17.7 10 1.77 HT-29 idem idem idem idem 22.8 13.6 1.68 B16-F0 idem idem idem idem 21.5 17.3 1. 24 MDA-MB-idem idem idem idem 40.3 19.6 2.05 231 R1R2R3R4C50(µM)G50(µM)C50/GCellline DU-145 H ethyl H cyclohe 16.2 6.9 2.35 (R xyl isomer) HT-29 idem idem idem idem 16.3 9.8 2.35 Caco-2 idem idem idem idem 15.6 9.9 1.57 B16-FOidem idem idem idem 17.7 15.5 1.14 MDA-MB-idem idem idem idem 32.5 16.3 1.99 231 EXAMPLES 17-29

Based on the formula of the compounds of the present invention as shown above, specific molecules were synthesized and later tested for citotoxic activity.

EXAMPLE 17 Ra R2 R3 R4 Methy) H Methoxy Methoxy (R-isomer)

Flash chromatography: 9/1: ether/petrol ether Rf = 0.31 (100% ether)

'H-NMR (CDCl3) : 6.95 (d, 1H, H-C2, J = 2.2 Hz), 6.72 (d, 1 H, H-C5, J = 8.4 Hz), 6.64 (dd, 1 H, H-C6, J = 2.0 and J = 8.4 Hz), 4.21 (m, 1 H, CH (CH3) CH2CI), 3.78 (s, 6H, 2 OCH3), 3.67 (dd, 1 H, CH2CI, J = 4.1 and J = 10.9 Hz), 3.50 (dd, 1H, CH2Cl, J = 3. 3 and J = 10.9 Hz), 1.17 (t, 3H, CH (CH3) CH2CI, J = 6.7 Hz).

EXAMPLE 18 R1 R2 R3 R4 methoxyMethoxyHMethyl (S-isomer)

Flash chromatography: 9/1: ether/petrol ether Rf = 0.33 (100% ether) 'H-NMR (CDCl3) : 6.96 (d, 1H H-C2, J = 2 Hz), 6.70 (d, 1 H, H-C5, J = 8.5 Hz), 6.63 (d, 1 H, H-C6, J = 8.5 Hz), 4.20 (m, 1 H, CH (CH3) CH2CI), 3.76 et 3.78 (2s, 6H, 2 OCH3), 3.65 (dd, 1 H, CH2CI, J = 4.2 and J = 11.0 Hz), 3.49 (dd, 1 H, CH2Cl, J = 3.4 and J = 11.0 Hz), 1.16 (t, 3H, CH (CH3) CH2Cl, J = 6.8 Hz).

EXAMPLE 19 R1 R2 R3 R4 H Ethyl Methoxy Methoxy (S-isomer)

Flash chromatography: 7/3: ether/petrol ether Rf = 0.17 (7/3: ether/petrol ether) 'H-NMR (CDCI3): 6.99 (d, 1 H, H-C2, J = 2.3 Hz), 6.80 (d, 1 H, H-C5, J = 8.4 Hz), 6.72 (d, 1 H, H-C6, J = 8.4 Hz), 4.04 (m, 1 H, CH (CH2CH3) CH2CI), 3.85 (s, 6H, 2 OCH3), 3.75 (dd, 1 H, CH2Cl, J = 3.9 and J = 11.2 Hz), 3.63 (dd, 1 H, CH2Cl, J = 3.3 and J = 11.2 Hz), 1.57 (m, 2H, CH (CH2CH3)CH2Cl), 0.93 (t, 3H, CH (CH2CH3) CH2Cl, J = 7.5 Hz).

EXAMPLE 20 R1 R2 R3 R4 H Ethyl Methoxy Methoxy (R-isomer)

Flash chromatography: 7/3: ether/petrol ether Rf = 0. 17 (7/3: ether/petrol ether)

'H-NMR (CDCl3) : 7.02 (d, 1 H, H-C2, J = 2.2 Hz), 6.77 (d, 1 H, H-C5, J = 8.7 Hz), 6.70 (dd, 1 H, H-C6, J = 2.2 and J = 8.7 Hz), 4.03 (m, 1 H, CH (CH2CH3) CH2CI), 3.83 (s, 6H, 2 OCH3), 3.73 (dd, 1 H, CH2Cl, J = 4.0 and J 11.2 Hz), 3.61 (dd, 1 H, CH2CI, J = 3.2 and J = 11.2 Hz), 1.56 (m, 2H, CH (CH2CH3)CH2Cl), 0.92 (t, 3H, CH (CH2CH3)CH2Cl, J = 7.4 Hz).

EXAMPLE 21 R1 R2 R3 R4 H Methyl H n-heptyl (R-isomer) Flash chromatography: 35/65: ether/petrol ether Rf = 0.16 (2/3: ether/petrol ether) 'H-NMR (CDCl3) : 7.15 (d, 2H, H-C2 and H-C6, J = 8.4 Hz), 7.07 (d, 2H, H-C3 and H-C5, J = 8.4 Hz), 4.25 (m, 1H, ch(CH3CH2Cl), 3.65 (dd, 1 H, CH (CH3) CH2CI, J = 4.5 and J = 11.0 Hz), 3.53 (dd, 1 H, CH (CH3) CH2CI, J = 3.6 and J = 11.0 Hz), 2.53 (t, 2H, CH3(CH2)5CH2, J = 7.8 Hz), 1.55 (m, 2H, CH3 (CH2) 4CH2CH2), 1.28 (m, 8H, CH3(CH2)4CH2CH2), 1.20 (d, 3H, CH (CH3) CH2Cl, J = 6.7 Hz), 0.87 (t, 3H, CH3 (CH2)6, J = 6. 8 Hz).

EXAMPLE 22 R1 R2 R3 R4 Hn-heptylHMehtyl (S-isomer)

Flash chromatography: 4/5/1: CH2Cl/petrol ether/ether Rf = 0.23 (2/3: ether/petrol ether) 'H-NMR (CDCl3) : 7.16 (d, 2H, H-C2 and H-C6, J = 8.3 Hz), 7.07 (d, 2H, H-C3 and H-C5, J = 8.3 Hz), 4.23 (m, 1 H, CH (CH3) CH2CI), 3.65 (dd, 1 H, CH (CH3) CH2Cl, J = 4.5 and J-11.0 Hz), 3.53 (dd, 1 H, CH (CH3) CH2Cl, J = 3. 5 and J = 11.0 Hz), 2.52 (t, 2H, CH3(CH2)5CH2, J = 7.7 Hz), 1.55 (m, 2H, (m,8H,CH3(CH2)4CH2CH2),1.19(d,3H,CH3(CH2)4CH2CH2),1.28 CH (CH3) CH2Cl, J = 6.6 Hz), 0.87 (t, 3H, CH3 (CH2) 6, J = 6.6 Hz).

EXAMPLE 23 R1 R2 R3 R4 Ethyl H H n-heptyl (S-isomer) Flash chromatography: 4/5/1: CH2Cl/petrol ether/ether Rf = 0.31 (2/3: ether/petrol ether) 'H-NMR (CDCl3) : 7.17 (d, 2H, H-C2 and H-C6, J = 8.2 Hz), 7.09 (d, 2H, H-C3 and H-C5, J = 8.2 Hz), 4.03 (m, 1 H, CH (CH2CH3)CH2Cl), 3.70 (dd, 1 H, CH (CH2CH3)CH2Cl, J=3. 7 and J = 11.0 Hz), 3.61 (dd, 1 H, CH (CH2CH3) CH2Cl, J = 3.2 and J = 11.0 Hz), 2.53 (t, 2H, CH3(CH2)5CH2, J = 7.7 Hz), 1.57 (m, 4H, CH3 (CH2) 4CH2CH2 and CH (CH2CH3)CH2Cl), 1.27 (m, 8H, CH3 (CH2) 4CH2CH2), 0.92 and 0.87 (2t, 6H, CH3 (CH2) 6 and CH (CH2CH3) CH2CI, J = 7.6 and J = 7.0 Hz).

EXAMPLE 24

R1 R2 R3 R4 Ethyl H H n-heptyl (R-isomer)

Flash chromatography: 4/5/1: CH2Cl/petrol ether/ether Rf = 0. 31 (2/3: ether/petrol ether) 'H-NMR (CDCI3): 7.16 (d, 2H, H-C2 and H-C6 J = 8. 5 Hz), 7.06 (d, 2H, H-C3 and H-C5, J = 8.5 Hz), 4.00 (m, 1 H, CH (CH2CH3) CH2CI), 3.67 (dd, 1 H, CH (CH2CH3)CH2Cl, J = 4.2 and J = 11.1 Hz), 3.58 (dd, 1 H, CH(CH2CH3)CH2Cl, J = 3.5 and J = 11.1 Hz), 2.53 (t, 2H, CH3(CH2)5CH2, J = 7.7 Hz), 1.54 (m, 4H, CH3 (CH2) 4CH2CH2 and CH (CH2CH3) CH2Cl), 1.28 (m, 8H, CH3 (CH2) 4CH2CH2), 0.91 and 0.87 (2t, 6H, CH3(CH2)6 and CH(CH2CH3)CH2Cl, J = 7. 4 and J =7.1 Hz).

EXAMPLE 25 R1 R2 R3 R4 Propy) H Propyl H cyclohexyl (racemic mixture)

Flash chromatography: 2/3: ether/petrol ether Rf = 0.31 (2/3: ether/petrol ether) 'H-NMR (CDCI3) : 7.16 (d, 2H, H-C2 and H-C6, J = 8.6 Hz), 7.08 (d, 2H, H-C3 and H-C5, J = 8.6 Hz), 4.08 (m, 1 H, CH (CH2CH2CH3)CH2Cl), 3.66 (dd, 1 H, CH, CI, =4.2 and J = 11.0 Hz), 3.55 (dd, 1 H, CH2Cl, J = 3. 6 and J = 11.0 Hz), 2.42 (m, 1 H, CH-Ph), 1.70-1.82 (m, 6H, CH (CH2CH2CH3) CH2CI and H- cyclohexyl), 1.20-1.60 (m, 8H, CH (CH2CH2CH3) CH2CI and H-cyclohexyl), 0.88 (t, 3H, CH(CH2CH2CH3)CH2Cl, J = 7.2 Hz).

EXAMPLE 26 R1 R2 R3 R4 Methyl H H n-hexyloxy (R-isomer) Flash chromatography: 1/1: ether/petrol ether Rf = 0.16 (1/1: ether/petrol ether) 'H-NMR (CDCl3) : 7.16 (d, 2H, H-C2 and H-C6, J = 8.7 Hz), 6.85 (d, 2H, H-C3 and H-C5, J = 8.7 Hz), 4.26 (m, 1 H, CH (CH3) CH2Cl), 3.92 (t, 2H, CH3 (CH2) 4CH20, J = 6.6 Hz), 3.72 (dd, 1 H, CH (CH3) CH2Cl, J = 4. 3 and J- 11.0 Hz), 3.55 (dd, 1 H, CH (CH3) CH2Cl, J = 3.5 and J = 11.0 Hz), 1.76 (m, 2H, (m,6H,CH3CH23CH2CH2O),1.21(d,3H,CH3(CH2)3CH2CH2O),1.24-1.50 CH (CH3) CH2Cl, J = 6.7 Hz), 0.90 (t, 3H, CH3 CH2 su, J = 6.9 Hz).

EXAMPLE 27

R1 R2 R3 R4 Methyl H H n-hexyloxy (S-isomer)

Flash chromatography: 55/35/10: CH2Cl2/petrol ether/ether Rf = 0.16 (1/1: ether/petrol ether) 'H-NMR (CDCI3): 7.13 (d, 2H, H-C2 and H-C6, J = 7.7 Hz), 6.79 (d, 2H, H-C3 and H-C5, J = 7.7 Hz), 4.21 (m, 1 H, CH (CH3) CH2CI), 3.87 (t, 2H, CH3 (CH2)4CH2O, J = 6. 5 Hz), 3.64 (dd, 1 H, CH (CH3) CH2Cl, J = 4.5 and J = 11.0 Hz), 3.52 (dd, 1 H, CH (CH3) CH2CI, J = 3.5 and J = 11.0 Hz), 1.74 (m, 2H, CH3(CH2)3CH2CH2O) 1.24-1.45 (m, 6H, CH3 (CH2) 3CH2CH2O), 1.18 (d, 3H, CH (CH3) CH2Cl, J = 6.6 Hz), 0.89 (m, 3H, CH3(CH2)5O).

EXAMPLE 28 R1 R2 R3 R4 Ethyl H n-hexyloxy (S-isomer)

Flash chromatography: 55/35/10: CH2CI2/petrol ether/ether Rf = 0.26 (1/1: ether/petrol ether) 'H-NMR (CDCI3): 7.16 (d, 2H, H-C2 and C6, J = 8.8 Hz), 6.82 (d, 2H, H-C3 and C5, J = 8.8 Hz), 4.01 (m, 1 H, CH (CH3) CH2CI), 3.90 (t, 2H, CH3 (CH2) 4CH20, J = 6.6 Hz), 3.70 (dd, 1 H, CH(CH2CH3)CH2Cl, J = 4.0 and J = 11.2 Hz), 3.60 (dd, 1 H, CH (CH2CH3) CH2CI, J = 3.3 and J = 11.2 Hz), 1.75 (m, 2H, CH3 (CH2) 3CH2CH2O), 1.20-1.70 (m, 8H, CH3 (CH2) 3CH2CH2O) and CH (CH2CH3) CH2CI), 0.90 (2t, 6H, CH3(CH2)5O and CH (CH2CH3)CH2Cl, J = 7.4 and J = 6.5 Hz).

EXAMPLE 29: EVALUATION OF CYTOTOXYCITY ACTIVITY: Cell culture. Tumor cell lines (B16-F0, Caco-2, DU-145, HT-29, MDA-MB-231 and other cell lines described so far in the patent application) were obtained from the American Type Culture Collection (ATCC HTB-26; Bethesda, MD).

Cells were grown in RPMI 1640 medium supplemented with 10% fetal bovine serum (Hyclone, Road Logan, Utah) and were cultured in a humidified atmosphere at 37 °C in 5% C02.

Drugs: All drugs were dissolve in DMSO and the final concentration of DMSO in the culture medium was maintained at 0.5 % (v/v).

Cytotoxiciy assays. At day-1, tumor cells in suspension in 100 µl were plated in microtiter plates (96 wells). On day-0, tumor cells were treated by addition of escalating concentrations of the drug (100, u1 solution). On that day, the number of living cells was determined in wells that were untreated. The number of living cells is determined using either MTT or resazurin assays. Growth inhibition activity of these compounds was expressed as the concentration of CEU inhibiting cell growth by 50% Gso in the following table The MTT assay was as described above in Example 1. The Resazurin assay was performed as follows:

Aspirate the supernatant (cell suspension: centrifuge first) Add 100, uL NaCI 0.9% (saline) Aspirate the supernatant (cell suspension: centrifuge first) Add 50, uL RZ (resazurin 125 µg/ml/PBS : RPMI without FBS; 1: 4) Incubate at 37°C Collect fluorescence data at different time.

FILTER EM EM CENTER 590 590 TABLE Vl IN-VITRO CYTOTOXIC ACTIVITY Cell line Rl R2 R3 R4 G50 (fjM) B16-F0 H Ethyl (R-isomer) H n-Heptyl 3,74 Caco-2 H Ethyl (R-isomer) H n-Heptyl 4, 85 CHO H Ethyl (R-isomer) H n-Heptyl 3,14 DU-145 H Ethyl (R-isomer) H n-Heptyl 4,02 HT-29 H Ethyl (R-isomer) H n-Heptyl 2, 94 K562 H Ethyl (R-isomer) H n-Heptyl 2,90 L1210 H Ethyl (R-isomer) H n-He tyl 4,04 MCF-7 H Ethyl (R-isomer) H n-Heptyl 3,78 MDA-MB-231 H Ethyl (R-isomer) H n-Heptyl 5,17 T24 H Ethyl (R-isomer) H n-Heptyl 3,61 B16-FO H Ethyl (R-isomer) Methoxy Methoxy > 100 Caco-2 H Ethyl (R-isomer) Methoxy Methoxy >100 CHO H Ethyl (R-isomer) Methoxy Methoxy > 100 DU-145 H Ethyl (R-isomer) Methoxy Methoxy > 100 HT-29 H Ethyl (R-isomer) Methoxy Methoxy > 100 K562 H Ethyl (R-isomer) Methoxy Methoxy > 100 L1210 H Ethyl (R-isomer) Methoxy Methoxy > 100 MCF-7 H Ethyl (R-isomer) Methoxy Methoxy > 100 MDA-MB-231 H Ethyl (R-isomer) Methoxy Methoxy > 100 T24 H Ethyl (R-isomer) Methoxy Methoxy > 100 B16-F0 H Ethyl (S-isomer) H n-Heptyl 4,77 Caco-2 H Ethyl (S-isomer) H n-Heptyl 6,32 CHO H Ethyl (S-isomer) H n-Heptyl 4,20 DU-145 H Ethyl (S-isomer) H n-Heptyl 4, 89 HT-29 H Ethyl (S-isomer) H n-Heptyl 5,01 Cell line R1 R2 R3 R4 G50 (uM) K562 H Ethyl (S-isomer) H n-Heptyl 3,59 L1210 H Ethyl (S-isomer) H n-Heptyl 5,67 MCF-7 H Ethyl (S-isomer) H n-Heptyl 4,20 MDA-MB-231 H Ethyl (S-isomer) H n-Heptyl 6,12 T24 H Ethyl (S-isomer) H n-Heptyl 3,93 B16-F0 H Ethyl (S-isomer) H n-Hexyloxy 8, 26 Caco-2 H Ethyl (S-isomer) H n-Hexyloxy 9, 50 CHO H Ethyl (S-isomer) H n-Hexyloxy 3, 28 DU-145 H Ethyl (S-isomer) H n-Hexyloxy 9,46 HT-29 H Ethyl (S-isomer) H n-Hexyloxy 8,12 ethyl(S-isomer)Hn-Hexyloxy3,88K562H L1210 H Ethyl (S-isomer) H n-Hexyloxy 7,42 MCF-7 H Ethyl (S-isomer) H n-Hexyloxy 10,41 MDA-MB-231 H Ethyl (S-isomer) H n-Hexyloxy 8,75 T24 H Ethyl (S-isomer) H n-Hexyloxy 7, 16 B 16-FO H Ethyl (S-isomer) Methoxy Methoxy > 100 Caco-2 H Ethyl (S-isomer) Methoxy Methoxy > 100 CHO H Ethyl (S-isomer) Methoxy Methoxy > 100 DU-145 H Ethyl (S-isomer) Methoxy Methoxy > 100 HT-29 H Ethyl (S-isomer) Methoxy Methoxy > 100 K562 H Ethyl (S-isomer) Methoxy Methoxy > 100 L1210 H Ethyl (S-isomer) Methoxy Methoxy > 100 MCF-7 H Ethyl (S-isomer) Methoxy Methoxy > 100 MDA-MB-231 H Ethyl (S-isomer) Methoxy Methoxy >100 T24 H Ethyl (S-isomer) Methoxy Methoxy > 100 B16-F0 H H H Cyclohexyl 7,77 Caco-2 H H H Cyclohexyl 9,37 CHO H H H Cyclohexyl 6,16 DU-145 H H H Cyclohexyl 9,09 HT-29 H H H Cyclohexyl 8,78 K562 H H H Cyclohexyl 7,12 L1210 H H H Cyclohexyl 6,94 MCF-7 H H H Cyclohexyl 10,73 MDA-MB-231 H H H Cyclohexyl 9,17 T24 H H H Cyclohexyl 7,57 B16-F0 H H H n-Heptyl 5,37 Caco-2 H H H n-Heptyl 8,07 CHO H H H n-Heptyl 5,39 Cell line R1 R2 R3 R4 G50 WM) DU-145 H H H n-Heptyl 7,16 HT-29 H H H n-Heptyl 4,90 K562 H H H n-Heptyl 3,85 L1210 H H H n-Heptyl 4,59 MCF-7 H H H n-Heptyl 8,62 MDA-MB-231 H H H n-Heptyl 7,87 T24 H H H n-Heptyl 3,41 HHn-Hexyloxy5,38B16-F0H Caco-2 H H H n-Hexyloxy 8,42 CHO H H H n-Hexyloxy 5,35 DU-145 H H H n-Hexyloxy 12, 41 HT-29 H H H n-Hexyloxy 6, 95 K562 H H H n-Hexyloxy 5, 13 L1210 H H H n-Hexyloxy 5,99 MCF-7 H H H n-Hexyloxy 9, 88 MDA-MB-231H H H n-Hexyloxy 10,18 T24 H H n-Hexyloxy 4, 28 B16-FO HHMethoxy Methoxy 35,33 Caco-2HHMethoxy Methoxy > 100 CHO H H Methoxy Methoxy 33,05 DU-145 H H Methoxy Methoxy 48,22 HT-29 H H Methoxy Methoxy 18,98 K562 H H Methoxy Methoxy 5,14 L1210 H H Methox Methoxy 19,82 MCF-7 H H Methoxy Methoxy 48,97 MDA-MB-231 H H Methoxy Methoxy > 100 T24 H H Methoxy Methoxy 20,59 B16-FO H Methyl (R-isomer) H n-Heptyl 3,79 Caco-2 H Methyl (R-isomer) H n-Heptyl 4,94 CHO H Methyl (R-isomer) H n-Heptyl 3,46 DU-145 H Methyl (R-isomer) H n-Heptyl 3,63 HT-29 H Methyl (R-isomer) H n-Heptyl 2,17 K562 H Methyl (R-isomer) H n-Heptyl 2,41 L1210 H Methyl (R-isomer) H n-Heptyl 2,42 MCF-7 H Methyl (R-isomer) H n-Heptyl 3,31 MDA-MB-231H Methyl (R-isomer) H n-Heptyl 4,64 T24 H Methyl (R-isomer) H n-Heptyl 2,18 B16-FO H Methyl (R-isomer) H n-Hexyloxy 6, 38 Cell line R1 R2 R3 R4 G50 (« M) Caco-2 H Methyl (R-isomer) H n-Hexyloxy 8, 57 CHO H Methyl (R-isomer) H n-Hexyloxy 2,63 DU-145 H Methyl (R-isomer) H n-Hexyloxy 13, 24 HT-29 H Methyl (R-isomer) H n-Hexyloxy 9,55 K562 H Methyl (R-isomer) H n-Hexyloxy 2, 68 L1210 H Methyl (R-isomer) H n-Hexyloxy 6,21 MCF-7 H Methyl (R-isomer) H n-Hexyloxy 8, 30 MDA-MB-231 H Methyl (R-isomer) H n-Hexyloxy 10,48 T24 H Methyl (R-isomer) H n-Hexyloxy 7,14 B16-FO H Methyl (R-isomer) Methoxy Methoxy 26,44 Caco-2 H Methyl (R-isomer) Methoxy Methoxy > 100 CHO H Methyl (R-isomer) Methoxy Methoxy 32,16 DU-145 H Methyl (R-isomer) Methoxy Methoxy 34,92 HT-29 H Methyl (R-isomer) Methoxy Methoxy 14,76 K562 H Methyl (R-isomer) Methoxy Methoxy 9,62 L1210 H Methyl (R-isomer) Methoxy Methoxy 10,34 MCF-7 H Methyl (R-isomer) Methoxy Methoxy 25,13 MDA-MB-231 H Methyl (R-isomer) Methoxy Methoxy 43,58 T24 H Methyl (R-isomer) Methoxy Methoxy 12,37 B16-F0 H Methyl (S-isomer) H n-Heptyl 6,60 Caco-2 H Methyl (S-isomer) H n-Heptyl 7,61 CHO H Methyl (S-isomer) H n-Heptyl 3,80 DU-145 H Methyl (S-isomer) H n-Heptyl 7,46 HT-29 H Methyl (S-isomer) H n-Heptyl 7,69 K562 H Methyl (S-isomer) H n-Heptyl 6,96 L1210 H Methyl (S-isomer) H n-Heptyl 7,48 MCF-7 H Methyl (S-isomer) H n-Heptyl 5,56 MDA-MB-231 H Methyl (S-isomer) H n-Heptyl 8,33 T24 H Methyl (S-isomer) H n-Heptyl 6,15 B16-F0 H Methyl (S-isomer) H n-Hexyloxy 8,45 Caco-2 H Methyl (S-isomer) H n-Hexyloxy 7,98 CHO H Methyl (S-isomer) H n-Hexyloxy 3,66 DU-145 H Methyl (S-isomer) H n-Hexyloxy 12,55 HT-29 H Methyl (S-isomer) H n-Hexyloxy 10,50 K562 H Methyl (S-isomer) H n-Hexyloxy 7,48 L1210 H Methyl (S-isomer) H n-Hexyloxy 8,20 MCF-7 H Methyl (S-isomer) H n-Hexyloxy 7,99 MDA-MB-231 H Methyl (S-isomer) H n-Hexyloxy 9,08 Cell line R1 R2 R3 R4 G50 (« M) T24 H Methyl (S-isomer) H n-Hexyloxy 9,93 B 16-F0 H Methyl (S-isomer) Methoxy Methoxy > 100 Caco-2 H Meth I (S-isomer) Methoxy Methoxy > 100 CHO H Methyl (S-isomer) Methoxy Methoxy > 100 DU-145 H Methyl (S-isomer) Methoxy Methoxy > 100 HT-29 H Methyl (S-isomer) Methoxy Methoxy > 100 K562 H Methyl (S-isomer) Methoxy Methoxy > 100 L1210 H Methyl (S-isomer) Methoxy Methoxy > 100 MCF-7 H Methyl (S-isomer) Methoxy Methoxy >100 MDA-MB-231 H Methyl (S-isomer) Methoxy Methoxy > 100 T24 H Methyl (S-isomer) Methoxy Methoxy > 100 B16-FO H Propyl (racemic H Cyclohexyl 4,14 mixture) Caco-2 H Propyl (racemic H Cyclohexyl 6,04 @@mixture) Propyl (racemic CHO H Cyclohexyl 2,12 mixture) DU-145 H Propyl (racemic H Cyclohexyl 4,30 mixture) Propyl (racemic HT-29 H H Cyclohexyl 3,03 mixture) Propyl (racemic K562 H H Cyclohexyl 4,93 mixture) Propyl (racemic L1210 H Cyclohexyl 4,12 mixture) Propyl (racemic MCF-7 H H Cyclohexyl 5,05 mixture) MDA-MB-231 H Propyl (racemic H Cyclohexyl 6,37 mixture) T24 H Propyl (racemic H Cyclohexyl 4,24 mixture)

Although the invention has been described above with respect with one specific form, it will be evident to a person skilled in the art that it may be modified and refined in various ways. It is therefore wished to have it understood that the present invention should not be limited in scope, except by the terms of the following claims.