Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D333/00—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
  • C07D333/02—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings
  • C07D333/04—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom
  • C07D333/26—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D333/38—Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P35/00—Antineoplastic agents
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P35/00—Antineoplastic agents
  • A61P35/04—Antineoplastic agents specific for metastasis
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D333/00—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
  • C07D333/02—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings
  • C07D333/04—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom
  • C07D333/26—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D333/38—Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals
  • C07D333/40—Thiophene-2-carboxylic acid
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D495/00—Heterocyclic compounds containing in the condensed system at least one hetero ring having sulfur atoms as the only ring hetero atoms
  • C07D495/02—Heterocyclic compounds containing in the condensed system at least one hetero ring having sulfur atoms as the only ring hetero atoms in which the condensed system contains two hetero rings
  • C07D495/04—Ortho-condensed systems

Definitions

• the present invention relates to triazene analogs of the general formula (I) and formula (II), their tautomeric forms, stereoisomers, polymorphs, hydrates, solvates, and pharmaceutically acceptable salts thereof for the metastatic malignant melanoma and other cancers including but not limited to lymphomas, sarcomas, carcinomas, and gliomas.
• the present invention further relates to a process for the preparation of the above said triazene analogs of formula (I) and formula (II), and their pharmaceutically acceptable compositions.
• Melanoma a malignant neoplasm
• Melanoma is derived from cells that are capable of forming melanin, arising most commonly in the skin of any part of the body and in the eye, or rarely, in the mucus membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or lentigo maligna.
• the cutaneous form is characterized by a proliferation of cells at the dermal epidermal junction which soon invades adjacent tissues.
• the cells vary in amount and pigmentation of cytoplasm; the nuclei are relatively large and frequently playful in shape, with prominent acidophilic nucleoli; the mitotic figures tend to be numerous.
• Melanomas frequently metastasize widely; regional lymph nodes, skin, liver, lungs, and brain are likely to be involved.
• UV radiation represents a definitive risk factor for skin cancer, especially when exposure occurs in combination with certain underlying genetic traits, such as red hair and fair skin (1).
• Pigmentation of the skin results from the synthesis of melanin in the pigment- producing cells, the melanocytes, followed by distribution and transport of pigment granules to neighboring keratinocytes. It is commonly believed that melanin is crucial for absorption of free radicals that have been generated within the cytoplasm by UV and acts as a direct shield from UV and visible light radiation (2, 3).
• UV-induced pigmentation requires induction of ⁇ -melanocyte-stimulating hormone ( ⁇ -MSH) secretion by keratinocytes.
• ⁇ -MSH and other bioactive peptides are cleavage products of Pro-Opiomelanocortin (POMC) (4).
• POMC Pro-Opiomelanocortin
• the p53 tumor suppressor gene is one of the most frequent targets for genetic alterations in cancer.
• p53 is a transcriptional regulator of the POMC gene, which translates to proteins that cause the melanocytes to produce melanin, which wards off skin cancer by absorbing UV radiation. Direct mutational inactivation of p53 is observed in close to half of all human tumors (5).
• DTIC dacarbazine
• CR Complete Response
• dacarbazine is also indicated for Hodgkin's lymphoma as a secondary line therapy when used in combination with other effective drugs.
• DTIC is 5-(3,3-dimethyl-l-trizeno)-imidazole-4-carboxamide with the following structural formula:
• the monomethyltriazene metabolite, 3-methyl-(triazen-l- yi)-imidazole-4-carboxamide (MTIC) is further hydrolyzed to 5-amino-imidazole-4- carboxamide (AIC), which is known to be an intermediate in purine and nucleic acid biosynthesis and to methylhydrazine, which is believed to be the active alkylating species.
• AIC 5-amino-imidazole-4- carboxamide
• Temozolomide is also a similar imidazotetrazine alkylator that methylates DNA at nucleophilic site.
• Temozolomide is orally bioavailable, more lipophilic, and spontaneously converted to MTIC, and also seems to generate less nausea (6).
• the O 6 - methylguanine adduct causes a mismatch during DNA replication and the addition of a thymidine, instead of cytosine, to the newly formed DNA strand (7).
• temozolomide Because of the excellent CNS biodistribution, temozolomide has been useful as a radiosensitizer in both primary brain tumors and CNS metastases (8-11).
• the pharmacokinetics of temozolomide has been studied in children, and clearance is related to body surface area (12). Temozolomide improves quality of life when used with radiation in patients with brain metastases.
• Temozolomide Unlike dacarbazine, Temozolomide has activity against sarcoma (13-15). Thus, it may be useful in sarcoma radiosensitization for primary control as well as for the treatment of metastases. Temozolomide is a radiosensitizer that is well tolerated and has modest side effects. The combination of Temozolomide and Irinotecan is more than additive against some cancers (16). The authors report that their experience confirms a high response rate in relapsed Ewing's sarcoma and DSRCT that is possibly even higher than that reported in the literature (17-19). The Temozolomide plus Irinotecan combination is less immune suppressive than standard cyclophosphamide-containing regimens (20).
• lymphocyte recovery i.e., absolute lymphocyte count >500 on day 15 after the first cycle of chemotherapy
• Temozolomide or dacarbazine has also been combined with other drugs including Gemcitabine and Doxorubicin liposomes (23,24).
• the disappearance of DTIC from the plasma is biphasic with an initial half life of 19 minutes and a terminal half life of five hours. In a patient with renal and hepatic dysfunctions, the half lives were lengthened to 55 minutes and 7.2 hours, respectively. The average cumulative excretion of unchanged DTIC in the urine is 40% of the injected dose in six hours.
• DTIC is subject to renal tubular secretion rather than Glomerular Filtration. At therapeutic concentrations, DTIC is not appreciably bound to human plasma protein.
• DTIC DTIC is extensively degraded. Besides unchanged DTIC, AIC is a major metabolite of DTIC excreted in the urine. Although the exact mechanism of action of DTIC is not known, three hypotheses have been offered:
• DTIC prior to its metabolism to the monomethyltriazene, is oxidized initially to monohydroxymethyl and finally to an aldehyde.
• the monomethyltriazene in its aldehyde form prior to oxidative monodemethylation, is cyclized to the cyclic compound (as shown in Scheme 1) which interferes with the double helix DNA structure and blocks replication of the cancer cells.
• the secondary metabolite, AIC is inactive.
• the imidazole ring system of the dacarbazine is hydrophilic in nature. Therefore, there is a need in the art for possibly effective binding to the melanin such that the cytotoxic functionality of the molecule is one hundred percent effective. Thus, the present inventors have aimed to provide novel compounds with increased lipophilicity thereby providing more target specificity.
• Thiophene which has a five-membered heterocyclic ring system, is lipophilic in nature and may have effective binding by increased avidity to the melanin, as a result, one would be able to get the same therapeutic effectiveness at a significantly lower dose, hence minimizing the toxicity. This would in turn afford high specificity with a larger window of the Therapeutic Index (TI).
• a larger therapeutic index is preferred. This is because, one would like to start the therapeutic regimen with a very high Maximum Tolerated Dose (MTD) such that the cancer cells would be hit hard in the first chemotherapy itself. Otherwise, the surviving cancer cells would repair the DNA damage and subsequently metastasize to the other organs. In addition, the cancer cells that survived from the first treatment would become resistant to the second chemotherapy again, if needed. And besides, due to weakness of the immune system from the first chemotherapy, a suboptimal dose would be given in the second treatment that would contribute to toxicity. As shown in scheme- 1, unlike DTIC, better interaction of the thiophene ring system with the -SH groups on the surface of the tumor antigen results in increased efficacy.
• MTD Maximum Tolerated Dose
• heterocyclic aromatic thiophene ring system may be superior over DTIC by way of inhibition of DNA synthesis by acting as a purine analog as well as acting as an alkylating agent.
• the present invention provides compounds of the formula (I), designated herein as 'triazene analogs'.
• R is independently selected from H, CH 3 , CH 2 OH
• R 1 is independently selected from OH, NHR 4 , NR 4 R 5 , SH
• R 4 and R 5 are independently selected from H, Ci-Ci 0 alkyl, alkenyl, alkylol, alkylamine, etc.
• X, Y, and Z are independently selected from C, N, O, and S such that the resulting five membered ring systems of the heterocyclic aromatic moieties are un-substituted and substituted thiophene, furan, thiazole, isothiazole, and furazole.
• the present invention also provides compounds of the formula (II)
• R 4 and R 5 are independently selected from H, Ci-Cio alkyl, alkenyl, alkylol, alkylamine, etc.
• X, Y, and Z are independently selected from C, N, O, and S such that the heterocyclic aromatic five membered ring of the fused bicyclic systems are un-substituted and substituted thiophene, furan, thiazole, isothiazole, and furazole.
• the present invention encompasses pharmaceutically acceptable salts of the compounds of the formula (I) and (II), for example organic or inorganic acid addition salts.
• the present invention provides compositions comprising atleast one triazene analog of formula (I) and/or formula (II) or pharmaceutically acceptable salts thereof and pharmaceutically acceptable carrier or diluents.
• the present invention provides compositions comprising atleast one triazene analog of formula (I) and/or formula (II) or pharmaceutically acceptable salts thereof and at lest one chemotherapeutic agent and optionally pharmaceutically acceptable carrier or diluents.
• compositions comprising triazene analogs of formula (I) and/or formula (II) or pharmaceutically acceptable salts thereof and at lest one chemotherapeutic agent and at least one biologic response modifying agent and optionally pharmaceutically acceptable carrier or diluents.
• the present invention provides a method of inhibiting cancer cell growth or killing a cancer cell in a patient by administering to a subject in need thereof, in an amount that is effective to kill a cancer cell, of a triazene analog of formula (I) and/or formula (II) or compositions containing the same or in combination with other chemotherapeutic agents thereof.
• Figure 1 illustrates line diagram showing percent increase in leaked Lactate dehydrogenase (LDH) from A2058 human melanoma cells, treated with various concentrations of Compound 1, Compound 6, Compound 13 and DTIC. Each point indicates percent increase in leaked LDH with respect to the vehicle control cultures, calculated from a mean of quadruplicate wells.
• LDH Lactate dehydrogenase
• Figure 2 illustrates bar diagrammatic representation of percent of cell viability of HS.531.sk normal human skin epithelial cells treated with different concentrations of DTIC and related test compounds (upper panel). Bar diagram at the lower panel represents the loss (in percentage) of HS.531.sk cell viability by various test compounds at 120 ⁇ g/ml as indicated.
• FIG 3 illustrates Western immunoblot image represents PARP cleavage in A2058 cells treated with 100 ⁇ g/ml of DTIC and test products Compound 1, Compound 6, and Compound 13. Control cultures received 0.5% DMSO as a vehicle. Expression of actin protein is shown as the loading control. Expression of the cleaved PARP protein at 89 kDa was normalized with actin expression (in arbitrary units), and represented as a bar diagram in the lower panel.
• Figure 4 represents images showing inhibition of B 16F0 colony formation in presence of DTIC and Compound 6 in vitro.
• B 16F0 cells were treated with either 0.1% DMSO (A), or 100 ⁇ g/ml of DTIC (B) or 50 ⁇ g/ml (C) or 100 ⁇ g/ml (D) of Compound 6.
• the average number of colonies and the average area of colonies in 0.1% DMSO (a), or 100 ⁇ g/ml of DTIC (b) or 50 ⁇ g/ml of compound 6 (c) or 100 ⁇ g/ml of compound 6 (d) treated cultures are represented in bar diagrams E and F, respectively.
• Figure 5 represents induction of cell cycle arrest in G2/M phase by Compound 6.
• B 16 FO Cells were treated with the indicated concentrations of either vehicle (0.1% DMSO) or DTIC or Compound 6 for 24h at different concentrations as indicated.
• the propidium iodide stained cells were analyzed for the distribution of cell cycle by FACS calibur, and the percentage of distribution at different phases of cell cycle was determined using ModFIT software. Data are shown as one representative of atleast three independent experiments.
• Figure 6 represents photomicrographs showing invaded B 16F0 cells in control (A), 100 ⁇ g/ml of DTIC (B), and Compound 6 (C) treated cultures.
• Bar diagram (D) represents the average number of invaded cells counted from 20 independent fields observed at 20 x objective.
• Figure 7 represents immunoblot image showing down-regulation of VEGF protein in Compound 6 treated B 16F0 cells.
• Bar diagram represents the normalized expression of VEGF protein in arbitrary units. Each bar represents the average expression calculated from atleast three independent experiments.
• FIG 8 shows inhibitory effect of Compound 6 on human endothelial cell migration.
• Microphotographs illustrate the migration of HUVECs in the presence of either DTIC (25 and 50 ⁇ g/ml at panels B and C, respectively) or Compound 6 (25 and 50 ⁇ g/ml at panel E and F, respectively).
• Panels A and D represent cellular migration in 0.1% DMSO treated vehicle control wells.
• the bar graph shows the number of migrated cells under different culture conditions as indicated under each bar. Each bar represents mean of migrated cells calculated from atleast twenty fields under 20 x objective.
• Figure 9 shows inhibition of capillary-like tube formation by Compound 6.
• Human umbilical vein endothelial cells were laid on Cultrex coated plates in presence of either DTIC (25 and 50 ⁇ g/ml at panels B and C, respectively) or Compound 6 (25 and 50 ⁇ g/ml at panels E and F, respectively) and allowed to form endothelial capillary tubes for 16 h at 37 0 C.
• Panels A and D represent capillary-like tube formation in 0.1% DMSO treated vehicle control wells.
• Figure 10 shows efficacy of Compound 6 and DTIC against B 16F0 tumor growth in C57B6J mice in vivo.
• the upper panel shows the photographs representing the size of tumors excised from sacrificed animals included in vehicle control (A and D), groups treated with 50 and 100 mg/kg of DTIC (B and C) and groups treated with 50 and 100 mg/kg of Compound 6 (E and F), respectively.
• the metastatic malignant melanoma is continued to be an incurable disease with median survival of approximately 8 months and the probability of surviving 5 years after the diagnosis is less than 5%.
• Response rates to combination regimens are reproducibly higher than with standard dacarbazine.
• any other combination dose regimens involving chemotherapeutic drugs, interleukins, interferons, and like biological response modifiers would make the malignant melanoma treatment more manageable and controlled.
• melanin binding moieties such as lipophillic thiophene system could offer a therapeutic treatment having all the three biochemical mechanisms of action superior to DTIC (Dacarbazine) with positive outcome leading to significantly increase in obtaining complete responses.
• DTIC diacarbazine
• the molecular structure we have chosen initially for our strategy involved a five membered heterocyclic thiophene ring system, which resembles and occupies similar shape and size to phenyl ring and is lipophilic in nature.
• thiophene ring structure has additional advantages internally built in that would aid in increasing the efficacy of the molecule by itself.
• the present invention aims to fulfill this unmet medical need of selectively binding to the targeted melanoma cells and sparing the normal cells thereby increasing the target to non-target cell ratio and further providing other related advantages as described herein. Accordingly, in an effort to increase the melanin binding, initially several compounds involving heterocyclic thiophene ring system as a backbone were considered. Due to the presence of large size sulfur atom, the five membered thiophene ring system would attain similar size and shape to a lipophillic six membered phenyl ring system in space. The substituted thiophene ring system, thus, in addition to it's aromatic nature would offer resonance derealization of electrons in the ring which may contribute to increased efficacy.
• the compounds of formula (I) and (II) of the present invention thiophene triazene analogs, having high affinity for melanin, thereby enhancing efficacy more efficiently.
• the novel analogs of the present invention may have been specifically designed to bind melanin more efficiently such that target to non- target ratio can be enhanced thereby decreasing the toxicity.
• the melanin binding analogs may be represented by the following:
• R is independently selected from H, CH 3 , CH 2 OH
• R 1 is independently selected from OH, NHR 4 , NR 4 R 5 , SH
• R 4 and R 5 are independently selected from H, CJ-CJO alkyl, alkenyl, alkylol, alkylamine, etc.
• X, Y, and Z are independently selected from C, N, O, and S such that the resulting five membered ring systems of the heterocyclic aromatic moieties are un-substituted and substituted thiophene, furan, thiazole, isothiazole, and furazole.
• the present invention also provides compounds of the formula (H):
• R 4 and R 5 are independently selected from H, CH 3, Ci-do alkyl, alkenyl, alkylol, alkylamine, etc.
• X, Y, and Z are independently selected from C, N O, and S such that the heterocyclic aromatic five membered ring of the fused bicyclic systems are un-substituted and substituted thiophene, furan, thiazole, isothiazole, and furazole.
• the compounds of the formulae (I) and (II) are disclosed together because of their structural similarities.
• the inactive compound of formula (I) upon in vivo activation by liver microsomal enzymes (cytochrome P450) followed by oxidative demethylation affords active monomethyltriazene analog.
• the compound of formula (II) upon in vivo hydrolysis affords similar monomethyltriazene analog of the enzymatically active species that derived from formula (I). Therefore, due to the similarities of their metabolites in vivo, in one embodiment, compound of formula (I) was disclosed, and in an another embodiment, compound of formula (II) were disclosed.
• the compounds of formula (I) and formula (II) are disclosed due to convenience and should be considered structurally similar due to biological reasons.
• Reagents & conditions (i) HCl, NaNO 2 , dimethylamine, O 0 C (ii) NH 3 , rt (iii) Aq. NaOH, methanol, rt
• thiophene-2-carboxylic acid provides an inseparable mixture of 4-nitrothiophene-2-carboxylic acid and 5- nitrothiophene-2-carboxylic acid, which is esterified to get the corresponding esters.
• the nitro functionality is then reduced to amines using iron powder and the mixture separated by silica gel column chromatography to obtain methyl 4-aminothiophene-2-carboxylate.
• the method for the synthesis of triazene analogs of formula (I) comprises the diazotization of the corresponding amine compounds using metal nitrate and an acid; the resulting diazotized product may be reacted with amines in presence of a base; finally the triazene ester may be converted to a carboxylic acid or a carboxylic amide.
• the inorganic acid may be hydrochloric acid, sulfuric acid, and the like and the organic acid may be benzoic acid, para- toluenesulfonic acid and the like.
• the method for the synthesis of triazene analogs of formula (I), wherein the analog of carboxylic acid may be produced by the hydrolysis of the corresponding ester using metal hydroxide in presence of a solvent.
• the metal hydroxide may be selected from sodium hydroxide or potassium hydroxide etc.
• the solvent is selected from water, methanol, ethanol, or mixtures thereof.
• the method for the synthesis of triazene analogs of formula (I), where the analog of carboxamide may be produced by the treatment of the corresponding ester with amine in presence of a base in a solvent at ambient temperature.
• the amine may be selected from ammonia, methyl amine, ethanol amine, ethylene diamine etc.
• the base is selected from potassium carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, pyridine, triethyl amine etc.
• the solvent is selected from tetrahydrofuran, methanol, ethanol, acetone, water or mixtures thereof.
• the present invention encompasses pharmaceutically acceptable salts of the compounds of the formula (I), and formula (II), for example organic or inorganic acid addition salts.
• the triazene analogs of the above formula (I) and formula (II) and derivatives thereof may be in the form of a solvate or a pharmaceutically acceptable salt, e.g., an acid addition or base addition salt.
• Such salts include hydrochloride, sulfate, phosphate, citrate, fumarate, methanesulfonate, acetate, tartrate, maleate, lactate, mandelate, succinate, oxalate, amino acids, and other suitable salts known in the art.
• the invention encompasses the optical enantiomers or diastereomers of the optically active compounds of formula (I), and formula (II).
• the present invention provides a pharmaceutical or veterinary composition (hereinafter, simply referred to as a pharmaceutical composition) that may contain a melanin targeted analog as described above, in admixture with a pharmaceutically acceptable carrier or diluents.
• a pharmaceutical composition that may contain a melanin targeted analog as described above, in admixture with a pharmaceutically acceptable carrier or diluent.
• compositions of the present invention may be in any form which allows for the composition to be administered to a subject.
• the composition may be in the form of a solid, liquid or gas (aerosol).
• Typical routes of administration include, without limitation, oral, topical, parenteral, sublingual, and rectal.
• parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques.
• Pharmaceutical compositions of the invention are formulated so as to allow the active ingredients contained therein to be bioavailable upon administration of the composition to a subject.
• Compositions that will be administered to a subject take the form of one or more dosage units, where for example, a tablet may be a single dosage unit, and a container of triazene in topical form may hold a plurality of dosage units.
• compositions should be pharmaceutically pure and non-toxic in the amounts used. It will be evident to those of ordinary skill in the art that the optimal dosage of the active ingredient(s) in the pharmaceutical composition will depend on a variety of factors. Relevant factors include, without limitation, the type of subject (e.g., human), the particular form of the active ingredient, the manner of administration and the composition employed.
• the pharmaceutical composition may include a melanin targeted analog or derivative thereof as described herein, in admixture with one or more carriers.
• the carrier(s) may be particulate, so that the compositions are, for example, in tablet or powder form.
• the carrier(s) may be liquid, with the compositions being, for example oral syrup or injectable liquid.
• the carrier(s) may be gaseous, so as to provide an aerosol composition useful in e.g., inhalatory administration.
• composition When intended for oral administration, the composition is preferably in either solid or liquid form, where semi-solid, semi-liquid, suspension and gel forms are included within the forms considered herein as either solid or liquid.
• the composition may be formulated into a powder, granule, compressed tablet, pill, capsule, chewing gum, water or the like form.
• a solid composition will typically contain one or more inert diluents or edible carriers.
• binders such as carboxymethylcellulose, ethyl cellulose, microcrystalline cellulose, or gelatin
• excipients such as starch, lactose or dextrins, cyclodextrins, disintegrating agents such as alginic acid, sodium alginate, primogel, corn starch and the like
• lubricants such as magnesium stearate or sterotex
• glidants such as colloidal silicon dioxide
• sweetening agents such as sucrose or saccharin, a flavoring agent such as peppermint, methyl salicylate or orange flavoring, and a coloring agent.
• composition When the composition is in the form of a capsule, e.g., a gelatin capsule, it may contain, in addition to materials of the above type, a liquid carrier such as polyethylene glycol or a fatty oil.
• a liquid carrier such as polyethylene glycol or a fatty oil.
• the composition may be in the form of a liquid, e.g., an elixir, syrup, solution, emulsion or suspension.
• the liquid may be for oral administration or for delivery by injection, as two examples.
• preferred composition contain, in addition to the present compounds, one or more of a sweetening agent, preservatives, dye/colorant and flavor enhancer.
• liquid pharmaceutical composition of the invention may include one or more of the following adjuvants: sterile diluents such as water for injection, saline solution, preferably physiological saline, Ringer's solution, isotonic sodium chloride, fixed oils such as synthetic mono or diglycerides which may serve as the solvent or suspending medium, polyethylene glycols, glycerin, propylene glycol or other solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfate; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or de
• a liquid composition intended for either parenteral or oral administration should contain an amount of the triazene analog of formula (I) and/or formula (II) such that a suitable dosage will be obtained. Typically, this amount is atleast 0.1% of a compound of the invention in the composition. When intended for oral administration, this amount may be varied to be between 0.1 and 80% of the weight of the composition. Preferred oral compositions contain between 4% and about 50% of the active triazene compound. Preferred compositions and preparations according to the present invention are prepared so that a parenteral dosage unit contains atleast 0.01% to 1% by weight of triazene analogs of formula (I) and/or formula (II).
• the pharmaceutical composition may be intended for topical administration, in which case the carrier may suitably comprise a solution, emulsion, ointment or gel base.
• the base for example, may comprise one or more of the following: petrolatum, lanolin, polyethylene glycols, beeswax, mineral oil, diluents such as water and alcohol, and emulsifiers and stabilizers.
• Thickening agents may be present in a pharmaceutical composition for topical administration.
• the composition may include a transdermal patch or ionophoresis device.
• Topical formulations may contain atleast 0.1 to about 10% w/v (weight per unit volume) concentration of the triazene analogs of formula (I) and/or formula (II).
• the composition may be intended for rectal administration, in the form, e.g., of a suppository which will melt in the rectum and release the drug.
• the composition for rectal administration may contain an oleaginous base as a suitable nonirritating excipient.
• bases include, without limitation, lanolin, cocoa butter and polyethylene glycol.
• the composition may include various materials which modify the physical form of a solid or liquid dosage unit.
• the composition may include materials that form a coating shell around the triazene analogs of formula (I) and/or formula (II).
• the materials which form the coating shell are typically inert, and may be selected from, for example sugar, shellac, and other enteric coating agents.
• the triazene analogs of formula (I) and/or formula (II) may be encased in a gelatin capsule.
• the pharmaceutical composition of the present invention may consist of gaseous dosage units, e.g., it may be in the form of an aerosol.
• aerosol is used to denote a variety of systems ranging from those of colloidal nature to systems consisting of pressurized packages. Delivery may be by a liquefied or compressed gas or by a suitable pump system which dispenses the triazene analogs of formula (I) and/or formula (II).
• Aerosols of compounds of the invention may be delivered in monophasic, biphasic, or triphasic systems in order to deliver the triazene analogs of formula (I) and/or formula (II). Delivery of the aerosol includes the necessary container, activators, valves, sub- containers, spacers and the like, which together may form a kit. Preferred aerosols may be determined by one skilled in the art, without undue experimentation.
• a pharmaceutical composition of the present invention comprising a compound of formula (I) and/or formula (II) or pharmaceutically acceptable salt thereof, and atleast one chemotherapeutic agent and optionally a pharmaceutically acceptable diluent or carrier.
• composition as said above wherein said chemotherapeutic agent is selected from the group consisting of dacarbazine (DTIC), temozolamide, methotrexate, doxorubicin, Cytoxan, 5-fluorouracil, cis-platin, carboplatin, oxaliplatin, vincristine, vinblastine, etoposide, irinotecan, topotecan, paclitaxel, docetaxel, taxotere, taxol, tamoxifen, gefitinib, adriamycin, gemcitabine, melphalan, streptozocin, floxuridine, 6- mercaptopurine, bleomycin, daunorubicin, Mitomycin-C, amsacrine, procabazine, capecitabine, avastin, herceptin, bexxar, velcade, zevalin, xeloda, erbitux (cetuximab)
• a composition intended to be administered by injection can be prepared by combining the triazene analogs of formula (I) and/or formula (II) with water so as to form a solution.
• a surfactant may be added to facilitate the formation of a homogeneous solution or suspension.
• Surfactants are compounds that non-covalently interact with the triazene analog or derivative so as to facilitate dissolution or homogeneous suspension of the triazene analogs of formula (I) and/or formula (II).
• An effective amount of a compound or composition of the present invention is used to treat diseases of cells having melanoma and other cancers. These cells are typically mammalian cells.
• Methods of administering effective amounts of the triazene analogs of formula (I) and/or formula (II) are well known in the art and include the administration of inhalation, oral or parenteral forms.
• dosage forms include, but are not limited to, parenteral solutions, tablets, capsules, sustained release implants and transdermal delivery systems; or inhalation dosage systems employing dry powder inhalers or pressurized multi-dose inhalation devices.
• the dosage amount and frequency are selected to create an effective level of the agent without harmful effects.
• a pharmaceutical composition comprising atleast one compound of formula (I) and/or formula (II) or pharmaceutically acceptable salt thereof, and atleast one chemotherapeutic agent and at lest one biologic response modifying agent and optionally a pharmaceutically acceptable diluent or carrier.
• Kits Containing Triazcne Analogs, and Preparation and Uses Thereof In another embodiment of the invention, a triazene analog as described above may be included in a kit for producing a triazene analog of the invention (melanin targeted analog) for pharmaceutical use.
• kits generally will be used in hospitals, clinics or other medical facilities with ready access on a daily basis to formulate such formulations.
• a method for inhibiting cancer cell growth or killing cancer cell in a patient by administering to said patient a therapeutically effective amount of compounds of formula (I) and formula (II).
• a method of treating a subject suffering from cancer disease wherein said cancer disease is of any type (solid, liquid, and lymphatic origin), and not limited to metastatic malignant melanoma, lymphomas (Hodgkins and non-Hodgkins), sarcomas (Ewing's sarcoma), carcinomas, brain tumors, central nervous system (CNS) metastases, gliomas, breast cancer, prostate cancer, lung cancer (small cell and non-small cell), colon cancer, pancreatic cancer, Head and Neck cancers, oropharyngeal squamous cell carcinoma, comprising the step of administering to said subject, an effective amount of compounds of formula (I) and/or formula (II).
• said cancer disease is of any type (solid, liquid, and lymphatic origin), and not limited to metastatic malignant melanoma, lymphomas (Hodgkins and non-Hodgkins), sarcomas (Ewing's sarcoma), carcinomas, brain tumors, central nervous system (CNS)
• a method of administration of compounds of formula (I) and formula (II) to a patient by any mode of delivery but not limited to intraperitoneal (IP), intravenous (IV), oral (PO), intramuscular (IM), intracutaneous (IC), intradermal (ID), intrauterine, intrarectal and the like.
• IP intraperitoneal
• IV intravenous
• PO oral
• IM intramuscular
• IC intracutaneous
• ID intradermal
• intrauterine intrarectal and the like.
• the compound 6 of formula (I) showed better anti-tumor activity than DTIC in B 16 FO melanoma xenograft model of C57B6J mice.
• compound 6 also showed dose response inhibition at the two dose levels tested.
• DTIC failed to show statistically significant dose response at the same two dose levels tested ( Figure 10). The failure of DTIC to demonstrate dose response is consistent with the literature reports, indicating that DTIC is an angiogenesis promoter, while our finding indicated that compound 6 is an angiogenesis inhibitor ( Figures 7, 9).
• Methyl 3-[(dimethylamino)diazenyI]thiophene-2-carboxylate To a solution of methyl 3-aminothiophene-2-carboxylate (0.5 g, 3.18 mmol) and cone. HCl (1.3 mL, 12.73 mmol) in H 2 O (7.5 mL) was added NaNO 2 (0.24 g, 3.50 mmol) in portions for 5 min at O 0 C.
• the reaction mixture was added to the solution Of K 2 CO 3 (1.66 g, 12.09 mmol) and dimethylamine (1.3 mL, 40%, 11.46 mmol) in H 2 O (9 mL) at O 0 C.
• the mixture was stirred at 0-5 0 C for 1 h and poured into ice cold water.
• the solution was extracted with chloroform (3 x 30 mL).
• the combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent.
• Methyl 3-amino-4-bromothiophene-2-carboxylate To a solution of methyl 3- aminothiophene-2carboxylate (1 g, 6.36 mmol) in acetic acid (10 mL) was added a solution of bromine (0.32 mL, 6.36 mmol) in acetic acid (1 mL) slowly for 5 min at rt and stirred at the same temperature for 16 h. The reaction mixture was poured into ice cold water and extracted with chloroform (3 x 100 mL). The combined organic layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent.
• Methyl 3-[dimethyIamino)diazenyl]-4-bromothiophene-2-carboxylate To a solution of methyl 3-amino-4-bromothiophene-2-carboxylate (0.5 g, 2.11 mmol) and cone. HCl (0.85 mL, 8.47 mmol) in H 2 O (5 mL) was added NaNO 2 (160 mg, 2.33 mmol) in portions for 5 min at 0 0 C.
• Methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate To a solution of methyl 3-aminothiophene-2-carboxylate (2.0 g, 12.7 mmol) and cone. HCl (5 mL, 50.8 mmol) in H 2 O (30 mL) was added NaNO 2 (0.96 g, 14.08 mmol) in portions for 5 min at O 0 C. After stirring 0.5 h at (0-5 0 C), the reaction mixture was added to the solution OfK 2 CO 3 (6.65 g, 48.26 mmol) and dimethylamine (5.14 mL, 40%, 45.7 mmol) in H 2 O (36 mL) at O 0 C.
• Methyl 3-[(dimethylamino)diazenyl]-5-nitrothiophene-2-carboxylate Methyl 3- [(dimethylamino)diazenyl]thiophene-2-carboxylate (2 g, 9.38 mmol) was added slowly for 15 min at 0 to -5 0 C to concentrated sulfuric acid (20 mL). Then concentrated nitric acid (0.54 mL, 70%, 10.7 mmol) was added to the above reaction mixture for 10 min and stirred at the same temperature for 1 h and rt for 16 h. The mixture was poured into ice cooled water and basified with ammonium hydroxide.
• Methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate Methyl 4- hydroxy-5-(methoxycarbonyl)thiophene-2-carboxylate (5 g, 23.14 mmol) was added slowly for 15 min at 0 to -5 0 C to concentrated sulfuric acid (25 mL). Then concentrated nitric acid (3.2 mL, 70%, 34.7 mmol) was added to the above reaction mixture for 10 min and stirred at the same temperature for 1 h. The mixture was poured into ice cooled water and extracted with ethyl acetate (3 * 100 mL). The combined organic layer was washed with water, brine and dried over sodium sulfate.
• Methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate To a solution of methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate (650 mg, 2.5 mmol) in acetone (20 mL) was added potassium carbonate (0.68 g, 5 mmol) at rt. Dimethyl sulfate (0.36 mL, 3.73 mmol) was added to the above reaction mixture slowly with stirring and a catalytic amount of KI was added. The mixture was refluxed for 4 h and the cooled reaction mixture was filtered and the solids were washed with acetone.
• Methyl 3-amino-4-methoxy-5-(methoxycarbonyI)thiophene-2-carboxylate To a solution of methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate (0.9 g, 3.27 mmol) in methanol (20 mL) was added cone. Hydrochloric acid (0.3 mL). To the above solution was added iron powder (0.91 g, 16.36 mmol) followed by an aqueous solution of ammonium chloride (0.87 g, 16.3 mmol, water: 5 mL) at rt. The reaction mixture was stirred and warmed to 70 0 C for 1 h and was then allowed to cool to rt.
• Methyl 3-[(dimethylamino)diazenyl]-4-metboxy-5-(methoxycarbonyI)thiophene-2- carboxylate To a solution of methyl 3-amino-4-methoxy-5- (methoxycarbonyl)thiophene-2-carboxylate (0.6 g, 2.44 mmol), cone. HCl (1 mL, 9.8 mmol) in H 2 O (10 mL) and acetone (10 mL) was added NaNO 2 (0.19 g, 2.7 mmol) in portions for 5 min at O 0 C.
• the reaction mixture was added to the solution OfK 2 CO 3 (1.28 g, 9.3 mmol) and dimethylamine (1 mL, 40%, 8.78 mmol) in H 2 O (8 mL) at O 0 C.
• the mixture was stirred at 0-10 0 C for 1 h and poured into ice cold water.
• the solution was extracted with chloroform (3 x 100 mL).
• the combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent.
• Methyl S-amino-S-phenylthiophene ⁇ -carboxylate To a solution of methyl thioglycolate (1 g, 9.43 mmol) in methanol (5 mL) was added a solution of sodium methoxide (0.5 g, 9.43 mmol) in methanol (5 mL) and stirred for 0.5 h. To the above mixture, a solution of 3-chloro-3-phenylprop-2-enenitrile (1.22 g, 7.5 mmol) in DMF (3.5 mL) was added dropwise for 10 min at rt and stirred the mixture at 6O 0 C for 2 h.
• Methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate To a solution of methyl 3-amino-5-phenylthiophene-2-carboxylate (5 g, 21.4 mmol) and cone. HCl (9 mL, 85.8 mmol) in H 2 O (51 mL) was added acetone (30 mL) to dissolve the product. Then NaNO 2 (1.7 g, 23.6 mmol) was added in portions for 15 min at O 0 C.
• the reaction mixture was added to the solution Of K 2 CO 3 (11.2 g, 81.5 mmol) and dimethylamine (8.5 mL, 40%, 77.2 mmol) in H 2 O (60 mL) at O 0 C.
• the mixture was stirred at 0-5°C for 1 h and poured into ice cold water.
• the solution was extracted with chloroform (3 x 100 mL).
• the combined CHCl 3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent.
• the solid was chromatographed over silica gel column using hexane-ethyl acetate (70:30) as eluents to give the product.
• the crude solid was recrystallized from hexane-chloroform to give the product as a pale pink color solid (1.1 g, 61%), mp 162-166 0 C.
• Methyl 4-aminothiophene-2-carboxylate To a solution of methyl nitrothiophene-2- carboxylates (7 g, 37.43 mmol) in a mixture of water (150 mL) and methanol (50 mL) was added Cone, hydrochloric acid (4.5 mL). To the above solution was added iron powder (10.5 g, 188 mmol) followed by ammonium chloride (1O g, 187 mmol) at rt. The reaction mixture was stirred and warmed to 70 0 C for 1 h and was then allowed to cool to rt. The solution was filtered and basified with saturated sodium bicarbonate solution. The solution was extracted with chloroform (4 x 100 mL).
• Methyl 4-[(dimethylamino)diazenyl]thiophene-2-carboxylate To a solution of methyl 4-aminothiophene-2-carboxylate (1.7 g, 10.82 mmol) and cone. HCl (4.6 mL, 43.5 mmol) in H 2 O (20 mL) was added NaNO 2 (0.84 g, 12.17 mmol) in portions for 5 min at O 0 C. After stirring for 0.5 h at 0-5 0 C, the reaction mixture was added to the solution OfK 2 CO 3 (5.8 g, 42 mmol) and dimethylamine (4.6 mL, 40%, 40.9 mmol) in H 2 O (30 mL) at O 0 C.
• Methyl 3-[(methoxycarbonyl)methylthio]propanoate Methyl acrylate (4.25 g, 49.5 mmol) was added dropwise over 20 min to a stirred solution of methyl thioglycolate (5 g, 47.16 mmol) and piperidine (0.10 mL) at rt. When about half of the acrylate had been introduced, more piperidine (0.10 mL) was added. After completion of the addition of the acrylate, the reaction mixture was stirred for 1 h at rt. The mixture was diluted with 100 mL of chloroform. The chloroform layer was washed with water, brine and dried over Na 2 SO 4 . The solution was filtered and evaporated the solvent to give the product as an oil (9 g, 100%). Step b:
• Methyl 4-oxo-2 v 3,5-trihydrothiophene-3-carboxyIate To a stirred slurry of sodium methoxide (1.68 g, 31.25 mmol) in dry THF (15 mL) was added a solution of dimethyl 3- thiahexanedioate (5 g, 26.03 mmol) in THF (10 mL) at rt for 5 min. The reaction mixture was heated at reflux for 2 h, cooled to rt and poured into ice cold water and acidified with dil. HCl. The solution was extracted with chloroform and the combined chloroform layer was washed with water, brine and dried over sodium sulfate.
• Methyl 4-aminothiophene-3-carboxylate hydrochloride A mixture of 4-oxo-3- methoxycarbonyltetrahydrothiophene (6.5 g, 40.62 mmol), hydroxylamine hydrochloride (2.84 g, 40.62 mmol) and acetonitrile (30 mL) was stirred under reflux for 1 h. The mixture was then cooled and the solid which separated was filtered off and washed with dry ether to afford the title compound (4.9 g, 62%), mp 192-196 0 C. Step d:
• Methyl 4-aminothiophene-3-carboxyIate Methyl 4-aminothiophene-3-carboxylate hydrochloride (290 mg) was dissolved in water (20 mL) and basified with ammonia solution. The solution was extracted with chloroform and the combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as pale yellow color oil (150 mg, 65%).
• Methyl 4-[(dimethylamino)diazenyl]thiophene-3-carboxylate To a solution of methyl 4-aminothiophene-3-carboxylate (200 mg, 1.27 mmol) and cone. HCl (0.5 mL, 5.09 mmol) in H 2 O (5 mL) was added NaNO 2 (96 mg, 1.39 mmol) in portions for 5 min at O 0 C. After stirring for 0.5 h at 0-5 0 C, the reaction mixture was added to the solution of K 2 CO 3 (665 mg, 4.8 mmol) and dimethylamine (0.5 mL, 40%, 4.57 mmol) in H 2 O (5 mL) at O 0 C.
• K 2 CO 3 665 mg, 4.8 mmol
• dimethylamine 0.5 mL, 40%, 4.57 mmol
• 2-An.inothiophene-3-carboxan.ide To a solution of 2,5-dihydroxy-l,4-dithiane (10 g, 65.78 mmol) in ethanol (200 mL) and triethylamine (2 mL) was added cyanoacetamide (5.52 g, 65.78 mmol) at rt for 5 min. The reaction mixture was refluxed for 3 h and attained to rt. Ethanol (appr. 150 mL) was removed under reduced pressure and poured the contents into ice cold water and stirred for 15 min.
• 3H-Thiopheno[2,3-d]l,2,3-triazin-4-one To an ice cold solution (O 0 C) of 2- aminothiophene-3-carboxamide (5 g, 35.21 mmol) in concentrated sulfuric acid (40 mL) was added a cold (O 0 C) solution of sodium nitrite (2.5 g, 35.21 mmol) in concentrated sulfuric acid (30 mL) for 30 min (while adding, the temperature should keep between -5- O 0 C). After addition, the mixture was stirred at the same temperature (O 0 C) for 3 h. The mixture was poured into crushed ice slowly with stirring for 15 min and stirred at the same temperature for 15 min.
• 3-Methylthiopheno[2,3-d]l,2,3-triazin-4-one To a solution of 3H-thiopheno[2,3- d]l,2,3-triazin-4-one (80 mg, 0.522 mmol) in acetone (50 mL) was added sequentially potassium carbonate (144 mg, 1.04 mmol), iodomethane (0.04 mL, 0.627 mmol) and potassium iodide (catalytic) at rt and the mixture was stirred at rt for 3 h. The solution was filtered and the solids were washed with acetone. Acetone was evaporated under reduced pressure, diluted with ice cold water and stirred for 10 min.
• 3-Amino-5-phenyIthiophene-2-carboxamide To a suspension of 3-amino-5- phenylthiophene-2-carbonitrile (150 mg) in aqueous sodium hydroxide solution (20 mL, 10%) was added ethanol (10 mL) and the mixture was refluxed for 1 h. The reaction mixture was allowed to attain rt and the crystals separated were filtered off, washed with cold water and dried to give the product as a golden yellow color solid (70 mg, 45%), mp 180-182 0 C.
• 6-Phenyl-3H-thiopheno[3,2-d]l,2,3-triazin-4-one To an ice cold solution (O 0 C) of 3- amino-5-phenylthiophene-2-carboxamide (0.37 g, 1.7 mmol) in concentrated sulfuric acid (20 mL) was added a cold (O 0 C) solution of sodium nitrite (120 mg, 1.86 mmol) in concentrated sulfuric acid (8 mL) for 10 min (while adding, the temperature should keep between -5-O 0 C). After addition, the mixture was stirred at O 0 C for 1 h and at rt for 1 h.
• the reaction mixture was cooled and poured into crushed ice slowly with stirring for 15 min and stirred at the same temperature for 15 min.
• the solution was extracted with ethyl acetate (3 x 50 mL) and the combined EtOAc layer was washed with water, brine and dried over sodium sulfate.
• the solution was filtered and evaporated the solvent to give the product as an off-white color solid (200 mg, 39%), mp 178-180 0 C.
• 3-Methyl-6-phenylthiopheno[3,2-d]l,2,3-triazin-4-one To a solution of 6-phenyl-3H- thiopheno[3,2-d] l,2,3-triazin-4-one (250 mg, 1.1 mmol) in acetone (25 mL) was added sequentially potassium carbonate (300 mg, 2.18 mmol), iodomethane (0.08 mL, 1.31 mmol) and potassium iodide (catalytic) at rt and the mixture was stirred at rt for 16 h. The solution was filtered and the solids were washed with acetone.
• Example 19 Cell proliferation assay using MTT based assay
• MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] incorporation based cell proliferation assay was performed using standard procedure with some modifications (38).
• the cytotoxic efficacy of the test compounds were evaluated in human malignant melanoma A2058 cells by MTT cell proliferation assay kit (Roche Applied Sciences, Germany).
• the assay was carried out according to the instruction provided by the vendor. Briefly, equal numbers of cells was plated in 96- well flat-bottomed plates in 100 ⁇ l of medium and were exposed to either DTIC or its derivative compounds at various concentrations up to 150 ⁇ g/ml for a period of three days. Vehicle control culture wells received only a maximum of 0.5% DMSO.
• Cytotoxicity potential of DTIC and its derivative compounds were evaluated by measuring the leaked lactate dehydrogenase (LDH) into the culture supernatant (LDH Cytotoxicity Detection Kit 1 " 1 " 5 , Roche Applied Sciences, Germany).
• LDH lactate dehydrogenase
• the leaked LDH is directly proportional to the cell damage done by the cytotoxic compounds.
• cells were treated with test compounds at various concentrations and incubated for 48 h. Vehicle control culture wells received only a maximum of 0.5% DMSO.
• the cell free culture supernatants were mixed with catalyst and dye solution and allowed to incubate for 15 min at room temperature. Finally, the reaction was stopped and the optical density was measured at 492 nm in a microplate reader (BioRad, USA).
• Example 22 Effect of the triazene compounds on the apoptotic cell death potential in A20S8 human melanoma cells
• Proteolytic cleavage of PARP by caspases is regarded as a hallmark of apoptosis.
• Caspase-3 cleaves the 113-kDa PARP to generate 89- and 24-kDa polypeptides (39).
• PARP cleavage assay has been performed on A2058 cells.
• PARP cleavage was estimated by using Western immunoblot assay as described earlier (40).
• Figure 3 illustrates comparative efficacy of PARP cleavage by the test compounds at a fixed dose of 100 ⁇ g/ml.
• the comparative anti-tumor growth potential of DTIC and Compound 6 was further tested in B 16F0 mouse melanoma cells and A375 human melanoma cells by using MTT based cell proliferation assay following the methodology described earlier (Example 19). Briefly, equal numbers of either B 16F0 or A375 cells were plated in 96-well flat- bottomed plates in 100 ⁇ l of medium and were treated with either DTIC or Compound 6 at different concentrations for 3 days. Vehicle control culture wells received only a maximum of 0.5% DMSO. After adding the MTT reagent, the cells were solubilized and the intracellular formazan formation was calorimetrically read at 540 nm in a microplate reader (BioRad, USA). The results (mean OD ⁇ SD) obtained from quadruplicate wells were used in calculation to determine the inhibition of cell proliferation (50% of inhibitory concentration, IC50) of the test compounds.
• Example 24 Comparative cytotoxicity potential of DTIC and Compound 6 on B16F0 mouse melanoma cells and A375 human melanoma cells
• Comparative cytotoxicity potential of DTIC and Compound 6 on B 16F0 mouse melanoma cells and A375 human melanoma cells were further evaluated by measuring the leaked lactate dehydrogenase (LDH) into the culture supernatant (LDH Cytotoxicity Detection Kit p
• Example 25 Anti-tumor efficacy of Compound 1 and Compound 6 in MCF-7 human breast tumor cells, MIA-PaCa2 human pancreas tumor cells and DU145 human prostate tumor cells.
• Anti-tumor growth potential of Compound 1 and Compound 6 were evaluated in MCF-7 human breast tumor cells, MIA-PaCa2 human pancreas tumor cells and DU 145 human prostate tumor cells by using MTT based cell proliferation studies as described earlier (example 19).
• the results (mean OD ⁇ SD) obtained from quadruplicate wells were used in calculation to determine the inhibition of cell proliferation (50% of inhibitory concentration, IC50) of the test compounds (Table 4).
• Example 26 B16 FO mouse melanoma cell colony formation assay
• Figure 4 shows inhibition of Bl 6 colony growth in DTIC and Compound ⁇ treated wells.
• Compound 6 exhibited significant inhibition in B 16 tumor cell colony growth compared with DTIC. 37.6%, 55.2% and 68.7% growth inhibitions were achieved by 100 ⁇ g/ml of DTIC, 50 ⁇ g/ml and 100 ⁇ g/ml of Compound 6, respectively.
• Example 27 Cell cycle analysis of Compound 6 treated B16 FO mouse melanoma cells
• B 16F0 cells were cultivated in DMEM containing 10% fetal bovine serum (FBS) in presence of 4.5 g/1 D- glucose. The sub confluent cells were treated with either DTIC or Compound 6 and incubated for 24h. Cells were harvested and prepared single cell suspension in buffer (PBS+2%FBS). The cells were washed twice with cold PBS and then fixed with cold 70% ethanol for 30 min. Ethanol was removed by centrifugation and the cells were suspended and the cell count was adjusted to 10 6 cells per ml.
• FBS fetal bovine serum
• the inhibitory effects of DTIC and compound 4 on In vitro invasive ability of B 16F0 were tested in cell invasion assay performed with by using Matrigel (BME - Cultrex®, R&D Systems, USA) coated cell culture inserts (Becton Dickinson, USA) with 8 ⁇ m- pore membrane. Equal number (fifty thousands) of B 16F0 cells were applied in each insert well and allowed to attach for 2h at 37 0 C and in presence of 5% CO 2 . Thereafter, the cellular invasion through the matrigel layer was performed in presence or absence of test compounds. Either 100 ⁇ g/ml of DTIC or Compound 6 was applied in the lower chamber of the invasion assembly. 0.1% DMSO was applied in the vehicle control culture chambers.
• Example 29 Compound 6 inhibits Vascular Endothelial Growth Factor (VEGF) production B16F0 cells
• B 16F0 cells were cultivated in Dulbecco's modified Eagle's red medium (DMEM) (Sigma Life Science, USA) containing 10% fetal bovine serum (FBS) and 4.5 g/1 D- glucose. Equal number cells (5x 10 4 ) were seeded in culture dishes (35x10 mm, 11.7 cm 2 ). The cells were treated with either 50 ⁇ g/ml of DTIC or Compound 4 for 24h. The cells incubated with only 0.1% DMSO was considered as vehicle control. After 24h, the cell lysates were prepared and analyzed for Vascular Endothelial Growth Factor (VEGF) expression by western blot assay as described earlier with appropriate modifications (43).
• DMEM Dulbecco's modified Eagle's red medium
• FBS fetal bovine serum
• Equal number cells (5x 10 4 ) were seeded in culture dishes (35x10 mm, 11.7 cm 2 ). The cells were treated with either 50 ⁇ g/ml of DTIC or Compound 4
• FALCONTM Cell Culture inserts (Becton Dickinson, USA) with 8 ⁇ m-pores in their PET membrane was coated with 0.1 mg/ml of collagen.
• Human umbilical vein endothelial cells (HUVEC) were added to the cell culture inserts (Becton Dickinson) at a density of 5 ⁇ l O 4 cells/insert. Cells were allowed to migrate through the insert for 18h in presence of different concentrations of either DTIC or Compound 6.
• the control culture containing migration assembly received only 0.1% DMSO.
• In vitro capillary formation assay was performed with Human umbilical vein endothelial cells (HUVEC), cultured on 10 mg/ml basement membrane extract (BME -Cultrex®, R&D Systems, USA) bed.
• the protocol of in vitro endothelial tube formation assay was the same as described earlier with some modifications (44). Briefly, four hundred microliters of Cultrex was coated at 4°C in each well of 24-well culture plate and allowed to gel at 37°C for 1 h.
• HUVECs were plated at a density of 7.5x10 4 cells per well with 400 ⁇ l of DMEM supplemented withl ⁇ % fetal bovine serum and 4.5 g/1 D-glucose.
• Example 32 Anti tumor growth potential of compound 6 in B16 FO melanoma xenograft model of C57B6J mice
• B16 FO melanoma xenograft model of C57B6J mice 45.
• C57B6J mice of 6 weeks age (body weight 18-22 g) were purchased from National Institute of Nutrition (NIN), India (India).
• Animals study protocols were approved by Institutional Ethics Committee (IAEC). All the studies were performed in compliance with the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA) guidelines and OECD guidelines. Animals were allowed free access to standard feed and provided charcoal filtered and UV exposed water ad libitum.
• the animals were maintained at a controlled temperature (24-26°C), humidity (45-70%), and 12h/12h of light/dark cycle.
• sub-confluent B 16F0 cells were harvested by brief trypsinization and IxIO 6 cells were injected subcutaneously in 0.2 ml phosphate- buffered saline.
• Drug treatment was started after development of palpable tumors (3-5 days after implantation of the cells).
• Drugs were prepared in phosphate-buffered saline (10% DMSO, v/v) and different doses of either DTIC or compound 6 were administered daily through intra-peritoneal route. Vehicle treated control animals received only 10% DMSO.
• Figure 10 shows comparative efficacy of inhibiting tumor growth by DTIC and compound 6 at various concentrations in B 16 FO melanoma xenograft model of C57B6J mice.
• VEGF-A 165 induces human aortic smooth muscle cell migration by activating neuropilin-l-VEGFRl-PI3K axis. Biochemistry, 2008, 47, 3345- 51.
• Sengupta, K., Banerjee, S., Dhar, K., Saxena, N.K., Mehta, S., Campbell, D.R., Banerjee, S.K. WISP-2/CCN5 is involved as a novel signaling intermediate in Phorbol ester protein kinase Calpha-mediated breast tumor cell proliferation. Biochemistry, 2006, 45, 10698-709.

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