Synthesis and pharmacological evaluation of some 4-oxo-quinoline-2-carboxylic acid derivatives as anti-inflammatory and analgesic agents

The synthesis and the pharmacological activity of a series of 1-aroyl derivatives of kynurenic acid methyl ester (4-oxo-quinolin-2-carboxy methyl (KYNA) esters), structurally related to NSAID indomethacin are described. The derivatives were screened in vivo for anti-inflammatory and analgesic activities. Most of the compounds exhibited good anti-inflammatory and analgesic activities. An automatic docking of the synthesized compounds was performed using X-ray structures of COX-1 and COX-2. Docking results are in good accordance with the experimental biological data.     

Synthesis and evaluation of some novel quinazolinone derivatives as diuretic agents

A new series of quinazolin-4(3H)-one derivatives containing either a thiazole or a 1, 3, 4-thiadiazole moiety were prepared in order to study the effect of such a heterocyclic combination on the expected diuretic activity. Synthesis of the target compounds (2, 4, and 6) has been achieved through an interaction of the starting 7-chloro-2-methyl-4H-3, 1-benzoxazin-4-one 1 with different heterocyclic amines. Alkylation of 3-(2-mercapto-1, 3, 4-thiadiazol-5-yl)quinazolin-4(3H)-one derivative 4 with different alkyl halides or chloroacetic acid afforded the corresponding thioethers 5 while interaction of 2-methyl-3-(1, 3, 4-thiadiazol-5-yl or thiazol-5-yl)quinazolin-4(3H)-ones (2 and 6) with various aromatic aldehydes resulted in the formation of the arylvinyl analogs 3 and 7, respectively. On the other hand, 2-morpholinomethyl-3-(2-sulfamoyl or mercapto-1, 3, 4-thiadiazol-5-yl)quinazolin-4(3H)-one derivatives 10 have also been synthesized through an interaction of the sulfonamide or thiol analog 9 with the appropriate amine. Biological evaluation of some of the target compounds as diuretic agents was carried out. The results showed that 2-[2-(4-chlorophenyl)vinyl]-7-chloro-3-(2-sulfamoyl-1, 3, 4-thiadiazol-5-yl)quinazolin-4(3H)-one 7b exhibited significant diuretic activity. The detailed synthesis, spectroscopic and biological data are reported.     

Synthesis and biological evaluation of some pyrazole derivatives as anti-malarial agents

Novel series of pyrazole derivatives were synthesized and tested for their in vivo anti‐malarial activity using mice infected with chloroquine sensitive P. berghei at a dose level of 50 µmol/kg. The most active compounds were further tested in vitro against chloroquine resistant (RKL9) strain of P. falciparum. The in vivo anti‐malarial activity study indicated that compounds 2a, 2b, 8a and 8b had mean percent suppression of 85%, 83%, 95% and 97%, respectively at equimolar dose level of the standard drug chloroquine diphosphate. Moreover, compounds 2a, 2b, 8a and 8b showed in vitro IC₅₀ values lower (p < 0.05) than that of the standard drug chloroquine phosphate (0.188 ± 0.003 µM) using the RKL9 strain. Compound 8b was the most active with IC₅₀ of 0.033 ± 0.014 µM. Generally, among the tested compounds, those containing a free carboxylic acid functional group on the pyrazole ring were the most active and this finding was supported by the docking results performed for the active compounds. The acute toxicity studies of the active compounds revealed that they have a good safety profile.     

Synthesis and biological evaluation of some hydroxypyrazole derivatives as anti-inflammatory-antimicrobial agents

Some hydroxypyrazole derivatives 2-7 were synthesized by cyclocondensation of the keto-ester 1 with hydrazines hydrate or substituted hydrazines followed by reduction and acylation with acetic anhydride or trifluoroacetic anhydride. The newly synthesized compounds were evaluated for their anti-inflammatory, antimicrobial activities. In addition, the ulcerogenic and acute toxicity profiles were determined. Compounds N-(4-(5-hydroxy-1-trifluoroacetyl-1H-pyrazol-3-yl)phenyl) trifluoroacetamide 4b, 3-(4-nitrophenyl)-1-(4-methoxyphenyl)-1H-pyrazol-5-ol 5b, and N-(4-(5-hydroxy-1-methyl-1H-pyrazol-3-yl)phenyl)trifluoroacetamide 7b were proved to be the most active anti-inflammatory, antimicrobial agents in the present study with a good safety margin and minimal or no ulcerogenic effect.     

Synthesis and evaluation of some new fluorinated hydroquinazoline derivatives as antifungal agents

The key intermediate octahydroquinazoline (1) was obtained in one pot synthesis by a modification of the Biginelli reaction. Compound 1 was allowed to react with phenacyl bromide and bromomalononitrile to furnish thiazolo[2,3-b]quinazoline 3 and 12, respectively. Interaction of compound 12 with formamide, formic acid and phenyl isothiocyanate yielded the corresponding pyrimidino[4',5':4.5]thiazolo[2,3-b] quinazolines 13, 14 and 17, respectively. The structure of the synthesized compounds were elucidated by elemental analyses and spectroscopic analyses. Some of the prepared compounds were tested for their antifungal activity in comparison with tioconazole as a reference fungicide.     

Synthesis and biological evaluation of some novel quinoxaline derivatives as anticonvulsant agents

In view of their expected anticonvulsant activity, some new derivatives of quinonxaline (V1-7) were designed and synthesized by condensation of different aromatic aldehydes with 2-(2-oxo-3-phenylquinoxalin-1(2H)-yl)acetohydrazide (IV). All synthesized compounds were isolated and confirmed by IR, 1H-NMR, MS, elemental analysis and then tested as anticonvulsant agents. Compound V3 and V1 showed the highest anticonvulsant effect with anticonvulsant potency relative to phenobarbital sodium of 0.8 and 0.75 whereas compound V5 exhibited the lowest relative potency of 0.09. The other compounds showed variable activity between these values as follows: V2 = 0.19, V4 = 0.41, V6 = 0.1 and V7 = 0.15. All compounds showed less activity than the reference compound phenobarbital. But the compounds provided a basis for further optimization.     

Synthesis of some novel D-glucuronic acid acetylated derivatives as potential anti-tumor agents

A structurally diverse series of Δ(4,5) -uronamide derivatives have been chemically synthesized starting from D-glucuronic acid itself by means of acetylation, activation, amide bond formation and base-catalyzed elimination protocols. Structure elucidation for all products along with optimization of the synthetic steps is described. The synthesized compounds were evaluated for their in-vitro anti-tumor activity against MCF-7, TK-10 and UACC-62 cell lines. The compounds 5, 11, 13, 15 and 16 were the most active against TK-10 cell line. On the other hand, the most active compounds against the MCF-7 cell line were 11 and 15. However, compounds 5, 7, 11, 13, 15 and 16 were the most active against the UACC-62 cell line.     

Synthesis and biological evaluation of sophocarpinic acid derivatives as anti-HCV agents

Chronic hepatitis C virus (HCV) infection has become a major public health burden worldwide. Twenty-two sophocarpinic acid or matrine derivatives were synthesized and their anti-HCV activities were evaluated in vitro. The structure-activity analysis revealed that (i) sophocarpinic acids with a D-seco 3-ring structure scaffold were more favorable than matrines with a 4-ring scaffold; (ii) the introduction of an electron-withdrawing group on the phenyl ring in 12-N-benzenesulfonyl Δ^βγ sophocarpinic acids was beneficial for the antiviral activity against HCV. Among them, compounds 9h and 9j exhibited the most potent inhibitory activities on HCV replication with selectivity indies of 70.3 and 30.9, respectively. Therefore, both were selected as antiviral candidates for further investigation.KEY WORDS: Sophocarpinic acid, Matrine, Anti-HCV, Antiviral activity, Structure−activity relationship     

Synthesis and biological evaluation of oleanolic acid derivatives as antitumor agents

Derivatives of oleanolic acid were synthesized and evaluated in vitro for their growth inhibition against human hepatocellular carcinoma cell line (HepG2) and colon cancer cell line (Col-02). Several derivatives exhibited moderate-to-good inhibitory activity, with 3 displaying the most promising inhibition [GI?? = 1.75 μM (HepG2), 0.71 μM (Col-02)]. Structure-activity relationship analyses of these derivatives demonstrated that a 1-en-2-cyano-3-oxo in ring A and a nitro at C-17 were important in retention of the inhibition against HepG2 and Col-02 cells.     

Synthesis and evaluation of some 1,2,3,4-tetrahydropyrimidine-2-thione and condensed pyrimidine derivatives as potential antihypertensive agents

Some new tetrahydropyrimidine-2-thione, octahydroquinazoline-2-thione and thiazolo[3,2-a]pyrimidine derivatives have been synthesized and tested for their antihypertensive activity. Among them, compounds 1 and 2b can be considered more potent than the reference, nifedipine (CAS 21829-25-4), while compounds 3b and 10a are equipotent to it. In addition, compound 6 showed significant antihypertensive activity.     

Synthesis and biological evaluation of some novel 2-phenyl benzimidazole-1-acetamide derivatives as potential anthelmintic agents

The present study describes synthesis of a series of 2-phenyl benzimidazole-1-acetamide derivatives and their evaluation for anthelmintic activity using Indian adult earthworms, Pheretima posthuma. The structure of the title compounds was elucidated by elemental analysis and spectral data. The compounds 4-({[2-(4-nitrophenyl)-1H-benzimidazol-1-yl]acetyl}amino) benzoic acid (3a), N-ethyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3c), N-benzyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3d), N-(4-hydroxyphenyl)-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3f), 2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl]-N-phenyl acetamide (3h), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N'-phenylacetohydrazide (3k), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-(4-nitrophenyl) acetamide (3n) and 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-phenyl acetamide (3q) were found better to paralyze worms whereas N-ethyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3c), N-(4-nitrophenyl)-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3e), 4-({[2-(4-chlorophenyl)-1H-benzimidazol-1-yl] acetyl}amino) benzoic acid (3j), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-ethyl acetamide (31) and 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-phenyl acetamide (3q) were better to cause death of worms compared to the anthelmintic drug albendazole.     

Synthesis of some new 2-(2-fluoro-4-biphenylyl)propionic acid derivatives as potential anti-inflammatory agents

The synthesis of a group of 1,3,4-oxadiazoles, 1,2,4-triazoles, 1,3,4-thiadiazoles and 1,2,4-triazine derived from 2-(2-fluoro-4-biphenylyl) propionic acid is described. The structures of new compounds are supported by IR, 1H NMR and MS data. These compounds were tested in vivo for their anti-inflammatory activity. The compounds which showed activity comparable to the standard drug flurbiprofen, were screened for their analgesic, ulcerogenic and lipid peroxidation activities. Five out of seventeen new compounds, showed very good anti-inflammatory activity in the carrageenan induced rat paw edema test with negligible ulcerogenic action. The compounds, which showed less ulcerogenic action, also showed reduced malondialdehyde production (MDA), which is one of the byproducts of lipid peroxidation. The study showed that the compounds inhibit the induction of gastric mucosal lesions and it can be suggested from our results that their protective effects may be related to an inhibition of lipid peroxidation in the gastric mucosa.     

Synthesis and biological evaluation of some quinazoline derivatives as antitumor and antiviral agents

A new series of 4-(4-aryl-1-piperazinyl)quinazolines 4a-f, 4-(3-substituted phenylamino)quinazoline derivatives 5a-h, 2-methoxycarbonylphenylaminoquinazoline derivatives 6a, b, 2-hydrazinocarbonylphenylaminoquinazolines 7a, b and 2-aryl-1-(substituted 4-quinazolinyl)-1,4-dihydro-5-oxo-5H-1,3,4-benzotriazepines 8a-j have been synthesized and tested for their antitumor and antiviral activities. Among them, compounds 5a-d exhibited broad spectrum antitumor activity with full panel median growth inhibition (GI50) at concentrations of 3.2, 2.0, 4.8, 4.0 mumol/l and total growth inhibition at concentrations of 56.5, 51.0, 63.0 and 73.0 mumol/l, respectively. Compounds 7a and 7b showed moderate selectivity toward leukemia cell line. On the other hand, compounds 8a and 8b showed moderate anti HIV-1 potency with EC50 values of 40.5 and 52.8 mumol/l, respectively. The detailed synthesis, spectroscopic and biological data are reported.     

Pharmacological evaluation of some new 2-substituted pyridine derivatives

In the present study, a series of 2-substituted-pyridines were synthesized and characterized by IR, (1)H-NMR and Elemental Analysis. The compounds were assayed against seizures induced by maximal electro shock (MES) and pentylenetetrazole (scMet). Neurologic deficit was evaluated by the rotarod test. The decrease in the elevated motor activity by introceptive chemical stimuli (amphetamine antagonistic activity) was studied at the dose level of 25 and 50 mg/kg, antihistaminic and cardiac activity were also studied. All the compounds exhibited significant anticonvulsant activity. Compounds 2-(2'-piperazino-ethanoxy)pyridine, 2-(3'-morpholino-2'-hydroxypropyloxy)pyridine, 2-(3'-piperidino-2'-hydroxypropyloxy)pyridine and 2-(3'-piperazino-2'-hydroxypropyloxy)pyridine were most active of the series against MES-induced seizures. Compounds 2-(2'-piperazino-ethanoxy)pyridine, 2-(2'-phenylamino-ethanoxy)pyridine, 2-(3'-imidazolo-2'-hydroxypropyloxy)pyridine, 2-(3'-methylamino-2'-hydroxypropyloxy)pyridine and 2-(3'-piperidino-2'-hydroxypropyloxy)pyridine exhibited significant decrease in the elevated motor activity at the dose of 50 mg/kg. Remarkable sympathetic blocking activity was observed with 2-(3'-piperazino-2'-hydroxypropyloxy)pyridine, 2-(3'-piperidino-2'-hydroxypropyloxy)pyridine and 2-(3'-imidazolo-2'-hydroxypropyloxy)pyridine only. Compounds 2-(2'-morpholino-ethanoxy)pyridine, 2-(2'-piperidino-ethanoxy)pyridine, 2-(2'-piperazino-ethanoxy)pyridine, 2-(2'-imidazolo-ethanoxy)pyridine, 2-(2'-diphenylamino-ethanoxy)pyridine, 2-(2'-diethanolamino-ethanoxy)pyridine, 2-(2'-phenylamino-ethanoxy)pyridine and 2-(2'-(4"-hydroxy)phenylamino-ethanoxy)pyridine exhibited significant blocking of histamine induced contraction on guinea pig ileum.     

Synthesis and evaluation as potential antitumor agents of novel ursolic acid derivatives

Novel ursolic acid derivatives were synthesized, and their structures were confirmed by MS, IR, ¹H NMR and ¹³C NMR spectral analysis. In vitro antitumor activities of these compounds against MGC-803 (gastric cancer cell) and Bcap-37 (breast cancer cell) human cancer cell lines were evaluated by MTT assay. The pharmacological screening results revealed that many derivatives exhibited moderate to high activities against the tested cell lines, and that most demonstrated more potent inhibitory activities than that of ursolic acid. Preliminarily mechanism study of representative compound 3h were carried out by acridine orange/ethidium bromide staining, Hoechst 33258 staining, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay, and flow cytometry which indicated that compound 3h can induce cell apoptosis of MGC-803 cells, and the apoptosis ratio reached 34.59?% after 36?h treatment at 10?μM.     

Synthesis and evaluation of some novel benzothiazole derivatives as potential anticancer and antimicrobial agents

Intensive efforts are underway worldwide to develop anticancer and antimicrobial agents. Therefore, a novel series of pyrido[2,1-b]benzo [d]thiazole and 2-(benzo [d] thiazol-2-ylamino)pyrimidine derivatives was synthesized. The synthesized compounds were evaluated for their anticancer activity. Among the tested compounds, compounds 3a, 3b, and 7 exhibited more cytotoxic action than the control drug doxorubicin (CAS 23214-92-8; IC50: 52 microg/ml). Compound 7 was the most potent cytotoxic, with an IC50 of 42.55 pg/ ml, while compounds 3a and 3b induced high cytotoxic action with IC50 values of 50.15 pg/ml and 50.45 pg/ml, respectively. Moreover, the synthesized compounds were screened for their antibacterial and antifungal activities. Compound 6 exhibited moderate antifungal activity against C. albicans with a minimum inhibitory concentration of 125 pg/ml.     

Synthesis of some 2-styrylquinazoline derivatives structurally related to certain chemotherapeutic agents

The synthesis of certain 2-styryl-4-arylaminoquinazolines having the general formula 1 is described. 4-Chloro-2-styrylquinazolines were prepared by chlorination of 2-styryl-4-quinazolones in benzene solution using phosphorus oxychloride and an excess of dimethylaniline. Reacting the chlorostyrylquinazolines with certain arylamines afforded 1.