Ş. Güniz Küçükgüzel

Synthesis, characterisation and biological activity of novel 4-thiazolidinones, 1,3,4-oxadiazoles and some related compounds

Two novel series of 4-thiazolidinone derivatives, namely 2-substituted-3-([4-(4-methoxybenzoylamino)benzoyl]amino)-4-thiazolidinones (7a-e) and 2-[4-(4-methoxybenzoylamino)benzoylhydrazono]-3-alkyl-4-thiazolidinones (5a-c) together with 2-[4-(4-methoxybenzoylamino)phenyl]-5-(substituted phenyl)amino-1,3,4-oxadiazoles (6a-c) have been synthesised as title compounds. N(1)-[4-(4-methoxybenzoylamino)benzoyl]-N(2)-substituted methylene hydrazines (3a-e) and 1-[4-(4-methoxybenzoylamino)benzoyl]-4-substituted phenyl thiosemicarbazides (4a-f) were also prepared and used as intermediate to give the title compounds. All synthesised compounds were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv and antimicrobial activities against various bacteria and fungi. Compounds 7a and 7b were found as the most active derivatives demonstrating 90 and 98% inhibition of mycobacterial growth of M. tuberculosis H37Rv in the primary screen at 6.25 microg mL(-1), respectively. However, level II assay revealed that the MIC values were not less than 6.25 microg mL(-1). None of the compounds showed significant antimicrobial activity against the microorganisms used whereas 3a and 7a inhibited the growth of several bacteria and fungi.

Synthesis, characterization and pharmacological properties of some 4-arylhydrazono-2-pyrazoline-5-one derivatives obtained from heterocyclic amines.

The synthesis of a new series of 4-arylhydrazono-2-pyrazoline-5-ones 7-24 and 22a is described. Structures of the synthesized compounds were confirmed using UV, IR, 1H-NMR, 13C-NMR and EI-mass spectral data. These compounds were tested in vitro against one Gram-positive and two Gram-negative bacterial strains, two mycobacterial strains and a fungus, Candida albicans. Compound 22 was found to be more active against Staphylococcus aureus than the other compounds at a concentration of 15.6 microg/mL. Some related compounds were evaluated for anticonvulsant activity. Compound 11 showed 40% protection against pentylenetetrazole-induced seizures in albino Swiss mice. In vitro antituberculosis activity of 4-arylhydrazono-2-pyrazoline-5-ones 7-12, 14-24, 22a and coupling products 6a-f were tested on Mycobacterium tuberculosis H37Rv. Of these compounds, only 24, which exhibited > 90% inhibition in the primary screen at 12.5 microg/mL against this strain was re-examined for determination of its actual MIC. However, level II assay revealed that the MIC value was not less than 12.5 microg/mL. The same compound was also tested against Mycobacterium avium, which was observed not to be susceptible to 24.

Recent advances in bioactive pyrazoles.

Pyrazole is a five membered and two-nitrogen containing heterocyclic ring. These structures have been investigated in the development of novel compounds with hypoglycemic, analgesic, anti-inflammatory, antimicrobial, anticonvulsant, antidepressant, antimycobacterial, antioxidant, antiviral, insecticidal and antitumor activities. Therefore, these compounds have been synthesized as target structures by many researchers and were evaluated for their biological activities. We hope that the bioactivity of pyrazole derivatives will be beneficial for the rational design of new generation of small molecule drugs. In this review, we report the structures of 1H-pyrazoles with their corresponding biological activities for 21st (in 2000-2014 years) century.

Synthesis, characterization of novel coupling products and 4-arylhydrazono-2-pyrazoline-5-ones as potential antimycobacterial agents.

Novel coupling products 7a-d and 4-arylhydrazono-2-pyrazoline-5-ones 8a-e were synthesized and evaluated for antimycobacterial activity against Mycobacterium tuberculosis H37Rv and Mycobacterium avium. Compound 7b was found to be the most potent derivatives of the 7a-d series by an MIC value of 6.25 microg/ml.

Recent advances bioactive 1,2,4-triazole-3-thiones.

Triazoles are heterocyclic compounds which have a five-membered ring of two carbon atoms and three nitrogen atoms. These structures have been interest in the development of novel compounds with anticonvulsant, antidepressant, antioxidant, anti-inflammatory, analgesic, antinociceptive, antibacterial, antimycobacterial, antifungal, antiviral, anticancer, anti-parasitic, anti-urease and other activities. Therefore, many researchers have synthesized these compounds as target structures and evaluated their biological activities. This review contains various pharmacological activities of 1,2,4-triazole-3-thiones in one place and it is also the milestone for the new research towards this moiety.

Synthesis, antiviral and anticancer activity of some novel thioureas derived from N-(4-nitro-2-phenoxyphenyl)-methanesulfonamide

Due to a continuing effort to develop new antiviral agents, a series of 1-[4-(methanesulfonamido)-3-phenoxyphenyl]-3-alkyl/aryl thioureas 3a-i have been synthesized by the reaction of alkyl/aryl isothiocyanates with 4-amino-2-phenoxymethanesulfonanilide. These derivatives were structurally characterized by the use of spectral techniques and evaluated for their anticancer and antiviral activities. None of the tested compounds showed significant anticancer properties on A549 and L929 cell lines. All synthesized compounds 3a-i were evaluated in vitro against HIV-1 (IIIB) and HIV-2 (ROD) strains in MT-4 cells, as well as other selected viruses such as HSV-1, HSV-2, Coxsackie virus B4, Sindbis virus and varicella-zoster virus using HEL, HeLa and Vero cell cultures. Compound 3b was able to block HIV replication with almost 100% maximum protection at 125 microg/ml, and IC(50) values of 54.9 microg/ml and 65.9 microg/ml against HIV-1 and HIV-2, respectively.

Synthesis, Cytotoxicity, and Pro-Apoptosis Activity of Etodolac Hydrazide Derivatives as Anticancer Agents

Etodolac hydrazide and a novel series of etodolac hydrazide‐hydrazones 3–15 and etodolac 4‐thiazolidinones 16–26 were synthesized in this study. The structures of the new compounds were determined by spectral (FT‐IR, 1H NMR, 13C NMR, HREI‐MS) methods. Some selected compounds were determined at one dose toward the full panel of 60 human cancer cell lines by the National Cancer Institute (NCI, Bethesda, USA). 2‐(1,8‐Diethyl‐1,3,4,9‐tetrahydropyrano[3,4‐b]indole‐1‐yl)acetic acid[(4‐chlorophenyl)methylene]hydrazide 9 demonstrated the most marked effect on the prostate cancer cell line PC‐3, with 58.24% growth inhibition at 10−5 M (10 µM). Using the MTT colorimetric method, compound 9 was evaluated in vitro against the prostate cell line PC‐3 and the rat fibroblast cell line L‐929, for cell viability and growth inhibition at different doses. Compound 9 exhibited anticancer activity with an IC50 value of 54 µM (22.842 µg/mL) against the PC‐3 cells and did not display any cytotoxicity toward the L‐929 rat fibroblasts, compared to etodolac. In addition, this compound was evaluated for caspase‐3 and Bcl‐2 activation in the apoptosis pathway, which plays a key role in the treatment of cancer.

Anti-cancer and anti-hepatitis C virus NS5B polymerase activity of etodolac 1,2,4-triazoles

Abstract Arachidonic acid is an unsaturated fatty acid liberated from phospholipids of cell membranes. NSAIDs are known as targets of cyclooxygenase enzyme (COX-1, COX-2 and COX-3) in arachidonic acid metabolism. This mechanism of COX-2 in carcinogenesis causes cancer. In addition, COX-2 plays a role in the early stages of hepatocarcinogenesis. Hepatitis C virus (HCV) infection is cause of liver cirrhosis and hepatocellular carcinoma (HCC). The aim of our study was to improve effective agents against HCV. A novel series of new etodolac 1,2,4-triazoles derivatives (4a–h) have been synthesized and investigated for their activity against HCV NS5B polymerase. Compound 4a was found to be the most active with IC50 value of 14.8 µM. In accordance with these results, compound 4a was screened for anti-cancer activity on liver cancer cell lines (Huh7, Mahlavu, HepG2, FOCUS). Compound 4a showed anti-cancer activity against Huh7 human hepatoma cell line with IC50 value of 4.29 µM. Therefore, compound 4a could be considered as a new anti-cancer and anti-HCV lead compound.

Synthesis of Tolmetin Hydrazide-Hydrazones and Discovery of a Potent Apoptosis Inducer in Colon Cancer Cells

Tolmetin hydrazide and a novel series of tolmetin hydrazide–hydrazones 4a–l were synthesized in this study. The structures of the new compounds were determined by spectral (FT‐IR, 1H NMR) methods. N′‐[(2,6‐Dichlorophenyl)methylidene]‐2‐[1‐methyl‐5‐(4‐methylbenzoyl)‐1H‐pyrrol‐2‐yl]acetohydrazide (4g) was evaluated in vitro using the MTT colorimetric method against the colon cancer cell lines HCT‐116 (ATCC, CCL‐247) and HT‐29 (ATCC, HTB‐38) to determine growth inhibition and cell viability at different doses. Compound 4g exhibited anti‐cancer activity with an IC50 value of 76 μM against colon cancer line HT‐29 (ATCC, HTB‐38) and did not display cytotoxicity toward control NIH3T3 mouse embryonic fibroblast cells compared to tolmetin. In addition, this compound was evaluated for caspase‐3, caspase‐8, caspase‐9, and annexin‐V activation in the apoptotic pathway, which plays a key role in the treatment of cancer. We demonstrated that the anti‐cancer activity of this compound was due to the activation of caspase‐8 and caspase‐9 involved in the apoptotic pathway. In addition, in this study, we investigated the catalytical effect of COX on the HT‐29 cancer line, the apoptotic mechanism, and the moleculer binding of tolmetin and compound 4g on the COX enzyme active site.

Detection of nimesulide metabolites in rat plasma and hepatic subcellular fractions by HPLC-UV/DAD and LC-MS/MS studies

SummaryNimesulide (4-nitro-2-phenoxymethanesulfonanilide) is an atypical NSAID lacking a carboxylic acid moiety. It has a good gastric tolerability due to selective inhibition of COX-2. The study objectives in the present work were to characterize the metabolism of nimesulide in rat plasma at certain time intervals. In vitro studies were also carried out to examine if nitroreduction takes place in vitro using rat hepatic subcellular fractions (microsomal and S9 fraction) besides aromatic hydroxylation. This communication describes detection and characterization of nimesulide metabolites isolated from plasma and hepatic subcellular post-incubates by the use of HPLC-UV/diode array and LC-MS/MS. Hydroxynimesulide was the major metabolite both in vivo and in vitro whereas nitroreduction was observed only in vitro with subcellular fractions under anaerobic conditions.