Kshipra S. Karnik

Synthesis and antimicrobial evaluation of novel ethyl 2-(2-(4-substituted)acetamido)-4-subtituted-thiazole-5-carboxylate derivatives

A series of novel molecules containing thiazole ring structure were designed and synthesized. The structures of the synthesized compounds were elucidated and confirmed by (1)H NMR, (13)C NMR, Mass spectrum and the purity was checked through HPLC analysis. Among these synthesized compounds, 3a-3i and 6a-6c were tested for their antimicrobial activity (minimum inhibitory concentration) against a series of strains of Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and against the strains of Candida albicans, Aspergillus flavus and Aspergillus niger for antifungal activity respectively. The results of the antimicrobial screening data revealed that most of the tested compounds showed moderate to good microbial inhibitions.

Facile Synthesis of Novel Coumarin Derivatives, Antimicrobial Analysis, Enzyme Assay, Docking Study, ADMET Prediction and Toxicity Study

The work reports the synthesis under solvent-free condition using the ionic liquid [Et3NH][HSO4] as a catalyst of fifteen novel 3-((dicyclohexylamino)(substituted phenyl/heteryl)-methyl)-4-hydroxy-2H-chromen-2-onederivatives 4a–o as potential antimicrobial agents. The structures of the synthesized compounds were confirmed by IR, 1H-NMR, 13C-NMR, mass spectral studies and elemental analyses. All the synthesized compounds were evaluated for their in vitro antifungal and antibacterial activity. The compound 4k bearing 4-hydroxy-3-ethoxy group on the phenyl ring was found to be the most active antifungal agent. The compound 4e bearing a 2,4-difluoro group on the phenyl ring was found to be the most active antibacterial agent. The mode of action of the most promising antifungal compound 4k was established by an ergosterol extraction and quantitation assay. From the assay it was found that 4k acts by inhibition of ergosterol biosynthesis in C. albicans. Molecular docking studies revealed a highly spontaneous binding ability of the tested compounds to the active site of lanosterol 14α-demethylase, which suggests that the tested compounds inhibit the synthesis of this enzyme. The synthesized compounds were analyzed for in silico ADMET properties to establish oral drug like behavior and showed satisfactory results. To establish the antimicrobial selectivity and safety, the most active compounds 4e and 4k were further tested for cytotoxicity against human cancer cell line HeLa and were found to be non-cytotoxic in nature. An in vivo acute oral toxicity study was also performed for the most active compounds 4e and 4k and results indicated that the compounds are non-toxic.

Imidazole-thiazole coupled derivatives as novel lanosterol 14-α demethylase inhibitors: ionic liquid mediated synthesis, biological evaluation and molecular docking study

A novel series of imidazole-thiazole coupled derivatives (7a–7q) were synthesized using Green protocol and identified by different spectroscopic techniques. The synthesized derivatives (7a–7q) were evaluated for their in vitro antifungal activity against the six fungi strains. The compounds 7j and 7k exhibited the most promising antifungal activity. The compound 7k exhibited extremely high antifungal activity against C. albicans, C. glabrata, F. oxysporum, A. flavus, A. niger, and C. neoformans with MIC80 values of 0.2, 0.2, 20, 35, 40, and 5 µg/ml respectively. The mode of action of the most promising antifungal compounds 7j and 7k was established by ergosterol extraction and quantitation assay. From the ergosterol extraction and quantitation assay it was found that the compounds 7j and 7k act by inhibition of ergosterol biosynthesis in C. albicans. The molecular docking study revealed the high spontaneous binding ability of the tested compounds to the active site of lanosterol 14α-demethylase, which proves that the tested compounds inhibit the synthesis of lanosterol 14α-demethylase. The synthesized compounds were analyzed for ADMET properties to establish oral drug like behavior and shows satisfactory results. To establish the antifungal selectivity and safety, the most active compounds were further tested for cytotoxicity against human cancer cell lines HeLa and K-562 and were found to be non-cytotoxic in nature. The in vivo acute oral toxicity study was performed for the most active compounds and results indicate that the compounds are non-toxic in nature.

Ionic Liquid-Promoted Synthesis of Novel Chromone-Pyrimidine Coupled Derivatives, Antimicrobial Analysis, Enzyme Assay, Docking Study and Toxicity Study

Herein, we report an environmentally friendly, rapid, and convenient ionic liquid ([Et3NH][HSO4])-promoted facile synthesis of ethyl 4-(6-substituted-4-oxo-4H-chromen-3-yl)-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives 4(a–f) and 4-(6-substituted-4-oxo-4H-chromen-3-yl)-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5- carbohydrazide derivatives 6(a–f). All the synthesized derivatives 4(a–f) and 6(a–f) were evaluated for their in vitro antifungal and antibacterial activity, by method recommended by National Committee for Clinical Laboratory Standards (NCCLS). The compound 6c bearing a fluoro group on the chromone ring and oxygen and a hydrazino group (–NHNH2) on the pyrimidine ring, was found to be the most potent antibacterial compound amongst the synthesized derivatives. The compound 6f bearing a methoxy group (–OCH3) on the chromone ring and sulphur group on the pyrimidine ring, was found to exhibit equipotent antifungal activity when compared with the standard drug miconazole. A d-alanine-d-alanine ligase (DdlB) enzyme assay study and an ergosterol extraction and quantitation assay study were performed to predict the mode of action of the synthesized compounds. A molecular docking study was performed to predict the binding interactions with receptors and mode of action of the synthesized derivatives. Further, analysis of the ADMET parameters for the synthesized compounds has shown that these compounds have good oral drug-like properties and can be developed as oral drug candidates. To establish the antimicrobial selectivity and safety, the most active compounds 6c and 6f were further tested for cytotoxicity against the human cancer cell line HeLa and were found to be non-cytotoxic in nature. An in vivo acute oral toxicity study was also performed for the most active compounds 6c and 6f and the results indicated that the compounds are non-toxic in nature.

Novel 2-(nitrooxy)ethyl 2-(4-(substituted phenyl)-2-((substituted phenyl)amino)thiazol-5-yl)acetate as Anti-inflammatory, Analgesic and Nitric Oxide Releasing Agents: Synthesis and Molecular Docking Studies

BACKGROUND Due to the need and adverse effects associated with the available anti-inflammatory agents, an attempt was made to develop the new anti-inflammatory agents with better activity and lesser adverse effects. OBJECTIVE Synthetic approaches based on chemical modification of NSAIDs have been undertaken with the aim of improving NSAIDs safety profile. METHOD In the present study, a series of thiazole derivatives (3a-3x) was synthesized and tested for its anti-inflammatory with analgesic and nitric oxide releasing properties. In this work, synthesis of molecules containing substituted diaryl ring on 5-membered thiazole ring with nitric oxide releasing moiety is described. RESULTS Out of the twenty four synthesized compounds, five compounds showed considerable anti-inflammatory and analgesic activity in comparison with the standard. Most of the synthesized compounds showed considerable nitric oxide-releasing property. The molecular docking study was used to rationalize binding interaction at the active site and the result showed good binding interaction. CONCLUSION From the results of pharmacological studies, we conclude that the synthesized compounds have not only retained, but showed enhanced anti-inflammatory and analgesic profile.

Synthesis and evaluation of [N-(Substituted phenyl)-2-(3-substituted) sulfamoyl) phenyl)] acetamide derivatives as anticancer agents

Abstract A series of molecules containing sulfonyl and amide coupling structure were developed, synthesized and evaluated. Total 21 compounds having sulfonamide and amide groups are synthesized. The structures of the synthesized compounds were elucidated and confirmed by 1H NMR, 13C NMR, Mass spectrum and the purity was checked through HPLC analysis. All synthesized compounds (4a–4u) were tested for their in vitro anticancer activity against a series of different cell lines like A549 (Lung Cancer cell), HeLa (Cervical), MCF-7 (Breast Cancer cell) and Du-145 (Prostate Cancer cell) respectively. The results of the anticancer activity revealed that most of the tested compounds showed moderate to good anticancer activity. Compounds 4d, 4k and 4s show promising anticancer activity in different cell lines.