Substituted naphthyridinyl hydrazines as anti-liver cancer agents

Abstract

The substituted naphthyridinyl hydrazine compounds as anti-liver cancer agents are anti-liver cancer agents that inhibit proliferative pathways of cancer cells, thereby exhibiting potent in vitro and in vivo anticancer activity. The compounds have the formula: ##STR00001##
wherein R.sub.1 and R.sub.2 each are selected independently from hydrogen, mercapto, and C.sub.1-C.sub.5-alkyl, preferably methyl, ethyl, propyl, isopropyl or halogen; R.sub.3 and R.sub.4 each are selected independently from hydrogen, alkyl or halogen; and R.sub.5 is selected from substituted or unsubstituted aryl, more preferably from substituted phenyl, naphthyl, and substituted or unsubstituted heteroaryl, more preferably from furyl, pyrrolyl, thienyl, imidazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, benzothiazolyl, oxadiazolyl or sugar moities. These agents exert their action through topoisomerase II inhibition.

Claims

1. A substituted naphthyridinyl hydrazine compound, comprising a compound having the formula: ##STR00016## wherein R.sub.1 and R.sub.2 each are selected independently from the group consisting of hydrogen, mercapto, halogen, and C.sub.1-C.sub.5 alkyl; R.sub.3 and R.sub.4 each are selected independently from the group consisting of hydrogen, alkyl and halogen; and R.sub.5 is a substituted or unsubstituted aryl or heteroaryl group Provided that R5 is not furyl.

2. The compound of claim 1, wherein: R.sub.1 and R.sub.2 each are selected independently from the group consisting of methyl, ethyl, propyl, and isopropyl; and R.sub.5 is selected from the group consisting of substituted phenyl, naphthyl, furyl, pyrrolyl, thienyl, imidazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, benzothiazolyl, and oxadiazolyl.

3. A method of treating a cancer patient, comprising the step of administering an effective amount of the compound of claim 2 to the patient.

4. The method of claim 3, wherein the patient is being treated for liver cancer.

5. A method of treating a cancer patient, comprising the steps of: obtaining a compound of claim 2; determining an appropriate dosing regimen for administering the compound to the patient; and administering the compound to the patient pursuant to the dosing regimen.

6. The method of claim 5, wherein the patient is being treated for liver cancer.

7. A method of preparing a compound according to claim 1, wherein R.sub.1 and R.sub.2 each are selected independently from the group consisting of hydrogen, mercapto, and C.sub.1-C.sub.5-alkyl; R.sub.3 and R.sub.4 each are selected independently from the group consisting of hydrogen, alkyl and halogen; and R.sub.5 is an aryl group, a heteroaryl group or a sugar moiety, the method following scheme 1: ##STR00017##

8. A method of preparing the compound according to claim 1, comprising the steps of: reacting a naphthyridine derivative of formula 2 with oxychloride, followed by addition of a first base in a first solvent; and adding a ketone of formula 3 in the presence of a catalytic amount of a second base to form the compound of formula 1.

9. The method of claim 8, wherein the first solvent is at least one solvent selected from the group consisting of ethyl alcohol, methyl alcohol, butyl alcohol, dioxane, tetrahydrofuran, and toluene; the second base is at least one base selected from the group consisting of trimethylamine, potassium carbonate, and piperidine, the second base being added with a second solvent comprising at least one solvent selected from the group consisting of ethyl alcohol, methyl alcohol, isopropyl alcohol, butyl alcohol, dioxane, toluene, and acetic acid; and the compound of formula 1 is recrystallized from a third solvent comprising at least one solvent selected from the group consisting of ethyl alcohol, methyl alcohol, benzene, acetic acid, and dimethyl formamide.

10. A method of treating a cancer patient, comprising the step of administering a pharmaceutical composition including an effective amount of the compound according to claim 1 to a patient in need thereof.

11. The method of claim 10, wherein the cancer patient has been diagnosed with liver cancer.

12. The substituted naphthyridinyl hydrazine compound of claim 1, wherein the compound has the formula: ##STR00018##

13. The substituted naphthyridinyl hydrazine compound of claim 1, wherein the compound has the formula: ##STR00019##

14. The substituted naphthyridinyl hydrazine compound of claim 1, wherein the compound has the formula: ##STR00020##

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a chart evaluating cytotoxic effects of substituted naphthyridinyl hydrazines according to the present invention on liver cancer HEPG2, as compared to prior art treating agents 5-Fluorouracil (5FU or 5F) and Doxorubicin (DOX or Dox), at different concentrations.

(2) FIG. 2 is the structural formula of Vosaroxin, a naphthyridinyl anti-liver cancer agent of the prior art.

(3) FIG. 3A is model showing binding of Vosaroxin (formerly Voreloxin, an anti-liver cancer agent of the prior art) with Topoisomerase II, and showing intermolecular hydrogen.

(4) FIG. 3B is a 3-D model of the interaction between Voreloxin, an anti-liver cancer agent of the prior art, and Topoisomerase II.

(5) FIG. 4A is model showing binding of compound 8b (a substituted naphthyridinyl hydrazine according to the present invention) with Topoisomerase II, and showing intermolecular hydrogen.

(6) FIG. 4B is a 3-D model of the interaction between compound 8b and Topoisomerase II.

(7) FIGS. 5A and 5B are a chart showing results of single-dose screening for various human cancer cell lines treated with compound 6 (a substituted naphthyridinyl hydrazine according to the present invention).

(8) FIGS. 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H, and 6I show dose response curves for various cancer cell lines treated with compound 6, plotted against the log.sub.10 of drug concentration.

(9) FIGS. 7A, 7B, and 7C are phase contrast micrographs showing morphological changes in HepG2 cells treated with compound 6 (a substituted naphthyridinyl hydrazine according to the present invention) over time, from before administration for the untreated control (FIG. 7A), 24 hours after administration (FIG. 7B), and 48 hours after administration of compound 6 (FIG. 7C).

(10) FIG. 8 is a reaction scheme showing synthesis of substituted naphthyridinyl hydrazines according to the present invention

(11) Similar reference characters denote corresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(12) The substituted naphthyridinyl hydrazine compounds as anti-liver cancer agents are anti-liver cancer agents that inhibit proliferative pathways of cancer cells, thereby exhibiting potent in vitro and in vivo anticancer activity. The compounds have the formula:

(13) ##STR00006##
wherein R.sub.1 and R.sub.2 each are selected independently from hydrogen, mercapto, and C.sub.1-C.sub.5-alkyl, preferably methyl, ethyl, propyl, isopropyl or halogen; R.sub.3 and R.sub.4 each are selected independently from hydrogen, alkyl or halogen; and R.sub.5 is selected from substituted or unsubstituted aryl, more preferably from substituted phenyl, naphthyl, and substituted or unsubstituted heteroaryl, more preferably from furyl, pyrrolyl, thienyl, imidazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, benzothiazolyl, oxadiazolyl or sugar moities. These agents exert their action through topoisomerase II inhibition.

(14) Preferred embodiments include the specific compound of formula 1 referred to below as the target compound, or compound 6, having the following structure:

(15) ##STR00007##
the specific compound of formula 1 referred to below as compound 8b, having the following structure:

(16) ##STR00008##
and the specific compound of formula 1 referred to below as compound 8c, having the following structure:

(17) ##STR00009##

(18) Surprisingly, it was found that compounds according of the above formulas possess anticancer activity, superior to the activity of known anticancer agents. In particular, it was found that some of the compounds described above exhibit an activity 1.5 times greater than that of 5-fluorouracil or doxorubicin, which are used as standard anticancer agents in the treatment of cancer.

(19) Vosaroxin, a naphthyridine derivative that is an anticancer drug in (phase III) clinical trials, exerts its action through topoisomerase II inhibition. FIG. 2 shows the chemical structure of Vosaroxin.

(20) The investigation showed that Vosaroxin has high affinity for docking in the binding site of topoisomerase II. Vosaroxin fits seamlessly into the active site of topoisomerase II and recorded a high binding energy score (DG=95.16 kcal/mol) by forming 8 hydrogen bonds with the amino acid residues at the binding site. Six of the hydrogen bonds were with the protein portion of topoisomerase II, and two of the hydrogen bonds were with the DNA segment. This indicates that Vosaroxin is intercalating with the DNA segment. The two hydrogen bonds formed with the DNA segment are both connected to the amino group of the Dc-9 and N-8 of the naphthyridine ring and OCH.sub.3 of the 7-pyrolidine substituent of Vosaroxin, while the remaining six hydrogen bonds are connected to Lys-723 (four bonds) and Gln-726 (two bonds) amino acids of topoisomerase II. See Table 1.

(21) A binding model of Vosaroxin with Topoisomerase II shows intermolecular hydrogen bonding. See FIG. 3A. A 3-D model also represents the interaction between Vosaroxin and Topoisomerase II. See FIG. 3B.

(22) In contrast, the present compound 6 recorded a docking score of 65.50 Kcal/mol, forming 1 hydrogen bond with the amino acid residues at the binding site. See Table 1.

(23) TABLE-US-00001 TABLE 1 Comparison of Vosaroxin and Compound 6 Docking Energy with Topoisomerase II No. of Compound Docking score Hydrogen Amino acid residues forming ID (Kcal/mol) bonds hydrogen bonds in A.sup.0 Vosaroxin 95.16 8 a K723 hz1 -- m M o3: 1.47 a K723 hz2 -- m M o2: 2.05 a K723 hz2 -- m M o3: 1.56 a K723 hz3 -- m M o3: 2.21 a Q726 he22 -- m M o3: 2.48 c C9 h42 -- m M n2: 2.02 c C9 h41 -- m M o4: 1.95 a Q726 oe1 -- m M h4: 2.71 Compound 6 65.50 1 d T10 o1p -- m M h10: 2.67

(24) Other compounds of formula 1 have also been shown to similarly bind with Topoisomerase II. In particular, a binding model of compound 8b with Topoisomerase II shows intermolecular hydrogen bonding.

(25) ##STR00010##
See FIG. 4A. And a 3-D model represents the interaction between compound 8c and Topoisomerase II.

(26) ##STR00011##
See FIG. 4B.

(27) The substituted naphthyridinyl hydrazine compounds are synthesized according to the method shown in the reaction scheme of FIG. 8. In the scheme shown in FIG. 8, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 each are independently selected from the group including hydrogen, halogen, C.sub.1-C.sub.5-alkyl, aryl, heteroaryl, naphthyl, mercapto, alkylthio, or alkylamino, or wherein R.sub.3 and R.sub.4 are members of a ring system in the resulting formula 1 compound. The proper naphthyridine derivative 2 (i.e., providing the R.sub.1, R.sub.2, and R.sub.3 substituents desired in the product structure) is reacted with an oxychloride (here, phosphorous oxychloride) at a temperature ranging from room temperature to about 210 C., preferably about 160-180 C., followed by treatment with base in a suitable solvent. Suitable solvents include, for example, ethyl alcohol, methyl alcohol, butyl alcohol, dioxane, tetrahydrofuran and toluene. Methyl alcohol gives 4-substituted-1,8-naphthyridine derivatives in good yield, followed by reaction with ketonic compounds (providing the desired R.sub.4 and R.sub.5 substituents) at temperatures ranging from room temperature to 110 C., preferably 80 C., in the presence of a catalytic amount of base.

(28) Suitable bases include triethylamine, potassium carbonate, or piperidine in a suitable solvent, such as ethyl alcohol, methyl alcohol, isopropyl alcohol, butyl alcohol, dioxane, toluene and acetic acid, preferably ethyl alcohol, to afford the target product 1.

(29) The product 1 can be purified by recrystallization from suitable solvent, for example, ethyl alcohol, methyl alcohol, benzene, acetic acid or dimethyl formamide.

(30) Male albino mice, weighing 18-20 g each, were used in a study. The mice were divided into three main groups, as follows. Group 1 is the untreated control group (5 mice); Group 2 is divided into two subgroups (5 mice in each subgroup), treated with either 5-FU (5-Fluorouracil) or DOX (Doxorubicin) as reference anticancer drugs. Group 3 is divided into ten subgroups (5 mice for each subgroup) and treated with the present substituted naphthyridinyl hydrazine compounds. The mice were housed in wide cages and well aerated rooms, and fed standard diets and clean water. Blood collection from the animals was done with heparinized cannula, and the mice were left alive.

(31) For treatment, in Group 1, each mouse was given a single intraperitoneal (i.p.) injection of 0.1 mL DMSO; in Group 2, each mouse was given a single i.p. injection of 0.1 mL containing 12 mg/kg body weight of 5-FU or DOX dissolved in sterile water; and in Group 3, each mouse was given a single intraperitoneal injection of 0.1 mL containing 12 mg/kg body weight of the selected furan derivatives dissolved in 0.01% DMSO. Blood was collected after 7 days from all mouse groups.

(32) The biochemical effects of formula 1 compounds on some liver enzymes in mouse blood serum was studied. Effects on aspartate and alanine aminotransferases (AST and ALT), and alkaline phosphatase (ALP), were examined using a blood auto analyzer, Olympus AV 400, Japan. Moreover, albumin, globulins, creatinine, total lipids, cholesterol, triglycerides, and bilirubin were evaluated, in comparison to treatment using 5-FU or DOX. Statistical analysis of the results was performed using Chi-square values (SPSS computer program). The results are reported in Table 2.

(33) TABLE-US-00002 TABLE 2 Effect of 5-FU, Dox, and Compound 6 on mice serum Mice Groups Biochemical 5-FU Doxorubicin Compound 6 Parameters Control P< P< P< Alanine 43.5 2.03 51.47 9.02 59.26 12.03 46.09 6.13 amino 0.001 0.001 n.s. transferase ALT (IU/ml) Aspartate 108.32 4.19 130.431 147.22 112.81 9.88 amino 8.92 16.34 n.s. transferase 0.001 0.001 AST (IU/ml) Alkaline 18.70 1.10 25.48 6.03 30.31 5.14 21.59 3.42 phosphatase 0.001 0.001 n.s. ALP (k.k./dl) Total Lipids 323.41 27.1 378.2 31.4 21.94 3.4 326.32 19.3 mg/dl 0.001 0.01 n.s. Cholestrol 94.32 13.5 105.9 11.7 109.3 14.2 93.24 19.53 mg/dl 0.001 0.001 n.s. Triglycerides 108.7 16.8 126.5 19.4 137.8 17.10 110.54 17.8 mg/dl 0.001 0.001 n.s. Bilirubin 0.63 0.04 0.75 0.10 0.81 0.19 0.76 0.15 mg/dl 0.001 0.001 0.01 Albumin 5.63 0.51 6.49 0.92 6.37 0.85 7.73 0.52 mg/d1 0.01 0.01 0.01 Globulin 4.32 0.9 5.75 0.8 5.91 0.63 6.25 0.82 mg/dl 0.01 0.01 0.01 A/G ratio 1.3 1.13 1.078 1.23 0.01 0.01 0.01 Creatinine 0.69 0.03 0.81 0.06 0.78 0.04 0.71 0.21 mg/dl 0.01 0.01 n.s Data are expressed as Mean + S.D. P < 0.01: significant; P < 0.001: highly significant; n.s.: non significant

(34) Biological evaluation of the present substituted naphthyridinyl hydrazine compounds revealed that the compounds possess a remarkable degree of anticancer activity. The results obtained clearly indicate the discovery of a new group of anticancer agents that induce their actions through topoisomerase II inhibition and revealed high affinity of the compounds of formula 1 toward the binding site of topoisomerase II. Therefore, anticancer activity of compounds of formula 1 is comparable to that of 5-FU and DOX. The present substituted naphthyridinyl hydrazine compounds have potential use as anticancer agents, with potency proved to be 5-6-fold more active than traditional anticancer drug 5-Fluorouracil (standard), while causing fewer toxic side effects.

(35) Single-dose screening with Compound 6 against a variety of cancer cell lines (including a variety of leukemia, non-small cell lung cancer, colon cancer, CNS cancer, melanoma, ovarian cancer, renal cancer, prostate cancer, and breast cancer cell lines) typically demonstrated significant decreases in cancer cell growth. See FIGS. 5A and 5B.

(36) The significant growth inhibition against these same cell lines was evaluated further using five different minimal concentrations of compound 6. The presented dose-response curves for each cell lines were plotted for the cytotoxic effect against the log.sub.10 drug concentration, as shown in FIGS. 6A-6I. Three parameters were determined, including the molar concentration of the drug that causes 50% growth inhibition (GI.sub.50), molar concentration that causes total growth inhibition (TGI), and the concentration that kills 50% of the cells (LC.sub.50).

(37) In the following examples, human cancer cell line HepG2 (Liver) was grown in DMEM media supplemented with 10% bovine serum, 1 penicillin-streptomycin (Sigma-Aldrich) at 37 C. in a humidified chamber with 5% CO.sub.2. 5-Flurourasil (Sigma-Aldrich) was used as the reference drug (standard).

(38) Cells were seeded (1105 cells/well in triplicate) in a 96-well flat-bottom plate (Becton-Dickinson Lab ware) a day before treatment and grown. Stocks of all extracts/compounds (1.0 mg/ml) were made with 5% DMSO (Sigma-Aldrich), and further working solutions (100 g/ml) were prepared in serum-free culture media. Cells were treated with four different doses (2, 6.2, 12.5, and 25 g/ml; in triplicate) of the compounds in complete growth media, including reference drug, and further incubated for 48 hours.

(39) On day 2 of treatment, cell proliferation and viability test was performed using TACS MTT Cell Proliferation and Viability Assay Kit (TACS), as per manufacturer's instructions. The relationship between surviving fraction and compound concentration was plotted to obtain the survival curve of cancer cell lines. The response parameter calculated was the IC.sub.50 value, which corresponds to the concentration required for 50% inhibition of cell viability.

(40) TABLE-US-00003 TABLE 3 Comparison of cytotoxic activity on liver HEPG2 cancer cell lines Compd. IC.sub.50 Compound 6 0.885 g/ml Fluorouracil 5 g/ml Doxorubicin 3.56 g/ml

(41) Fat free human serum albumin (HSA), calf thymus DNA (sodium salt, average molecular weight 1106), RPMI 1640 medium, fetal bovine serum (FBS), MTT dye, trypsin EDTA solution, ethidium bromide, Tris base (Tris-(hydroxymethyl)-amino-methane-hydrogen chloride) and agarose were purchased from Sigma-Aldrich (St. Louis, Mo., USA). All other chemicals used for analysis were also obtained from Sigma-Aldrich (St. Louis, Mo., USA).

(42) The cells were seeded in 6-well plates and allowed to adhere at 37 C. in a CO.sub.2 incubator. After 24 h, each well was treated with 10 g compound and incubated for the indicated time. After 24 and 48 hrs, the cells were imaged by phase contrast microscope (Olympus CLX 41) to visualize morphological changes in HepG2 cells. See FIGS. 7A-7C.

(43) The precise instructions for pharmaceutical administration of the compounds and agents according to the present subject matter necessarily depend on the requirements of the individual case, the nature of treatment, and of course the treating physician.

Example 1

(E)-2-(2-Substituted Arylidene)-1-(2,7-disubstituted Naphthyridinyl) Derivative

(44) ##STR00012##

(45) Ketonic derivatives (10 mmol) and a catalytic amount of acetic acid were added to a suspension of the intermediate 3 (10 mmol) (see FIG. 8) in dry ethanol 30 ml. The reaction mixture was refluxed for about 3 hours. Reaction completion was monitored by TLC. The reaction mixture was concentrated under reduced pressure. The crystalline product was collected by filtration, dried and crystallized from methanol to give the required product of formula 1. Yield 73%, mp: 231-233 C.; IR (KBr, cm.sup.1) .sub.max: 3221, 1665; .sup.1H NMR (DMSO-d.sub.6) : 2.59 (s, 6H), 6.90-8.73 (m, 8H), 9.63 (s, 1H); .sup.13C NMR (DMSO-d.sub.6) : 23.91, 107.72, 119.23, 121.46, 125.11, 128.19, 130.94, 131.01, 132.85, 133.87, 134.96, 142.58, 154.82, 157.16, 157.79, 159.77; MS: m/z 355 (M.sup.+) consistent with the molecular formula, (C.sub.17H.sub.15BrN.sub.4).

Example 2

(E)-2-(2-Nitrobenzylidene)-1-(2,7-dimethyl-1,8-naphthyridin-5-yl)hydrazine (Compound 6)

(46) ##STR00013##

(47) To a solution of hydrazide derivative (10 mmol) in absolute ethyl alcohol (30 mL), was added o-nitrobenzaldehyde (10 mmol) and catalytic amount of piperidine. The reaction mixture was refluxed for about 5 h (Reaction completion was monitored by TLC), then left to cool. The solid precipitate formed was collected by filtration, dried, and recrystallized from methyl alcohol to afford the target product of formula 6. Yield 76%, mp: 255-256 C.; IR (KBr, cm.sup.1) .sub.max: 3210 (NH), 1624 (CN); .sup.1H NMR (DMSO-d.sub.6) : 2.61 (s, 6H, 2CH.sub.3), 6.85-8.14 (m, 8H, ArH+NCH), 9.76 (s, 1H, NH, exchangeable); .sup.13C NMR (DMSO-d.sub.6) : 23.87, 110.34, 120.54, 121.18, 123.95, 126.32, 130.09, 131.86, 134.40, 134.79, 145.01, 148.62, 154.89, 157.47, 158.01, 160.12; Mass spectrum, m/z (I.sub.rel, %): 321 (15) [M].sup.+, consistent with the molecular formula (C.sub.17H.sub.15N.sub.5O.sub.2). Anal. Calcd. for C.sub.17H.sub.15N.sub.5O.sub.2 (321.33): C, 63.54; H, 4.71; N, 21.79. Found: C, 63.41; H, 4.59; N, 21.65.

Example 3

(3Z)-3-[2-(2,7-Dimethyl-1,8-naphthyridin-4-yl)hydrazinylidene]-1,3-dihydro-2H-indol-2-one (8b) and (3Z)-5-chloro-3-[2-(2,7-dimethyl-1,8-naphthyridin-4-yl)hydrazinylidene]-1,3-dihydro-2H-indol-2-one (Compound 8)

(48) In the general procedure, a stirred solution of hydrazide 1 (5 mmol), and indoline-2,3-dione or 5-chloroindoline-2,3-dione (5 mmol) in acetic acid (20 mL) was refluxed for 1-3 h. The reaction mixture was cooled to room temperature, poured into crushed ice and the solid product was filtered off, washed with ethanol, dried and recrystallized from (AcOH-ether) to afford the target compounds 8b and 8c, respectively.

Example 4

(3Z)-3-[2-(2,7-Dimethyl-1,8-naphthyridin-4-yl)hydrazinylidene]-1,3-dihydro-2H-indol-2-one Compound 8b

(49) ##STR00014##

(50) Yield 83%, mp >300 C.; IR (KBr, cm.sup.1) .sub.max: 3238, 3190 (2NH), 1667 (CO), 1610 (CN); .sup.1H NMR (DMSO-d.sub.6) : 2.60 (s, 6H, 2CH.sub.3), 6.90-8.12 (m, 7H, ArH), 9.65, 10.26 (2s, 2H, 2NH, exchangeable); .sup.13C NMR (DMSO-d.sub.6) : 24.05, 110.28, 118.21, 120.47, 121.58, 124.01, 124.45, 129.37, 131.25, 132.74, 134.42, 147.02, 155.43, 157.61, 158.10, 159.12, 167.23; Mass spectrum, m/z (I.sub.rel, %): 317 (34) [M].sup.+, consistent with the molecular formula (C.sub.18H.sub.15N.sub.5O). Anal. Calcd. for C.sub.18H.sub.15N.sub.5O (317.34): C, 68.13; H, 4.76; N, 22.07. Found: C, 67.98; H, 4.63; N, 21.89.

Example 5

(3Z)-5-Chloro-3-[2-(2,7-dimethyl-1,8-naphthyridin-4-yl)hydrazinylidene]-1,3-dihydro-2H-indol-2-one Compound 8c

(51) ##STR00015##

(52) Yield 71%, mp >300 C.; IR (KBr, cm.sup.1) .sub.max: 3245, 3195 (2NH), 1668 (CO), 1620 (CN); .sup.1H NMR (DMSO-d.sub.6) : 2.63 (s, 6H, 2CH.sub.3), 6.90-8.15 (m, 6H, ArH), 9.17, 10.38 (2s, 2H, 2NH, exchangeable); .sup.13C NMR (DMSO-d.sub.6) : 24.01, 110.36, 119.22, 120.52, 123.05, 124.12, 129.46, 130.01, 131.38, 132.81, 134.29, 145.02, 155.48, 157.42, 158.14, 159.10, 167.43; Mass spectrum, m/z (I.sub.rel, %): 351 (12) [M].sup.+, consistent with the molecular formula (C.sub.18H.sub.14ClN.sub.5O). Anal. Calcd. for C.sub.18H.sub.14ClN.sub.5O (351.79): C, 61.46; H, 4.01; N, 19.91. Found: C, 61.37; H, 3.87; N, 19.77.

Example 6

Measurement of Potential Cytotoxicity by SRB Assay

(53) Cells were plated in 96-well flat-bottom plate (10.sup.4 cells/well) and grown for 24 h before treatment with the target compound(s) to allow attachment of cells to the wall of the plate. Different concentrations of the compound under test (0, 1, 2.5, 5, 10 g/mL) were added to the cell monolayer. Triplicate wells were prepared for each individual dose. Monolayer cells were incubated with the compound(s) for 48 h at 37 C. and in an atmosphere of 5% CO.sub.2. Cultures were then fixed with trichloroacetic acid and stained for 30 min with 0.4% (w/v) sulforhodamine B (SRB) dissolved in 1% acetic acid. Unbound dye was removed by four washes with 1% acetic acid, and protein-bound dye was extracted with 10 m unbuffered Tris base [tris(hydroxymethyl)aminomethane] for determination of optical density in a computer-interfaced, 96-well microtiter plate reader. The SRB assay results were linear with the number of cells and with values for cellular protein measured by both the Lowry and Bradford assays at densities, ranging from sparse subconfluence to multilayered supraconfluence. The signal-to-noise ratio at 564 nm was approximately 1.5 with 1,000 cells per well. The relation between surviving fraction and drug concentration is plotted to get the survival curve of the cancer cell line after the specified compound.

Example 7

Effect of the Formula 1 on Some Biochemical Parameters in Mice

(54) Data obtained in Table 2 presents the liver enzymatic activities (ALT, AST and ALP) in serum of control and treated groups of mice. The results showed that the values recorded for AST and ALT were significantly higher (P<0.001) with 5-FU- and DOX-treated groups of mice than the control. On the other hand, treatment with the new compound caused inverse effects, where some values recorded for AST and ALT were non-significant (n.s.) or slightly higher (P<0.01) in comparison to control. Moreover, the recorded data showed that ALP activities were significantly increased (P<0.001) with the treatment of 5-FU and DOX, while there were no significant changes in ALP activities upon treatment with the new compound.

Example 8

Microscopy Studies

(55) A. The cells were seeded in 6-well plates and allowed to adhere at 37 C. in CO.sub.2 incubator. After 24 h, each well was treated with 10 g of compound 6 and incubated for the indicated time. After 24 and 48 hrs, the cells were imaged by phase contrast microscope (Olympus CLX 41) to visualize morphological changes in HepG2 cells. See FIGS. 7A-7C.

(56) B. Similar studies were done with HeLa cells. Cells were seeded in 6-well plates and allowed to adhere at 37 C. in CO.sub.2 incubator. After 24 h, each well was treated with 4.6 M 2,6P-OLA and incubated for the indicated time. After 12 and 24 h, the cells were imaged by phase contrast microscope (Olympus CLX 41) to visualize morphological changes in HeLa cells.

Example 9

Morphological Analyses

(57) A. Change in HepG2 cells after treatment with compound 6 was studied for morphological variations using the phase contrast microscopy. Changes in surface morphology of the HepG2 cells were observed after 24 and 48 hrs (FIGS. 7A-7C).

(58) B. Change in LeLa cells after treatment with compound 6 was also studied for morphological variations using the phase contrast microscopy. Changes in surface morphology were observed after 12 and 24 hrs to visualize morphological changes in HeLa cells.

(59) Many characteristic features occur in cells undergoing a series of biochemical events during apoptosis. Various morphological changes, such as blebbing, loss of membrane asymmetry, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation occur. In FIG. 7B, cells exposed to 10 g of compound for 24 hours show the onset of apoptotic characteristics, where most of the cells lose their typical branch-shaped morphology and cause shrinking of cell. After 48 hours of exposure, blebbing and loss of basal attachment and membrane asymmetry is markedly seen, as shown in FIG. 7C.

(60) It is to be understood that the present subject matter is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.