Microwave assisted synthesis, characterization and investigation of antibacterial activity of 3-(5- (substituted-phenyl)-4,5-dihydro-1H-pyrazol-3- yl)-2H-chromen-2-one derivatives

A variety of 3-(5-(substituted-phenyl)-4,5-dihydro-1H-pyrazol-3-yl)-2H-chromen-2-one derivatives 3a–j were synthesized through microwave assisted thermal annulation of corresponding a,b-unsaturated ketones (chalcones) 2a–j via hydrazinolysis. Chalcones 2a–j were prepared from 3-acetyl-coumarin 1 which was previously accessed by Pechmann condensation reaction of salicylaldehyde. The series of pyrazoline-based coumarin motifs 3a–j synthesized, were structurally confirmed by analytical and spectral data. They were then evaluated for their antimicrobial activities using agar diffusion method. The result showed that microwave assisted method (MAM) for the reaction was remarkably successful and gave the targeted products 3a–j in higher yields at shorter reaction times compared to conventional synthetic method (CSM). The results showed that these skeletal frameworks exhibited marked potency as antibacterial agents. The most active antibacterial agent was 3-(5-(4- (diethylamino) phenyl)-4,5-dihydro-1H-pyrazol-3-yl)-2H-chromen-2-one 3j with MIC and MBC values of 3.92 ± 0.22 mg/mL and 7.82 ± 0.43 mg/mL respectively.The World Academy of Sciences (TWAS)https://www.tandfonline.com/loi/tabs20am2020Chemistr

Synthesis, in silico and in vitro antimicrobial efficacy of substituted arylidene-based quinazolin-4(3H)-one motifs

Introduction: Quinazolin-4(3H)-one derivatives have attracted considerable attention in the pharmacological profiling of therapeutic drug targets. The present article reveals the development of arylidene-based quinazolin-4(3H)-one motifs as potential antimicrobial drug candidates.Methods: The synthetic pathway was initiated through thermal cyclization of acetic anhydride on anthranilic acid to produce 2-methyl-4H-3,1-benzoxazan-4-one 1, which (upon condensation with hydrazine hydrate) gave 3-amino-2-methylquinazolin-4(3H)-one 2. The reaction of intermediate 2 at its amino side arm with various benzaldehyde derivatives furnished the final products, in the form of substituted benzylidene-based quinazolin-4(3H)-one motifs 3a–l, and with thiophene-2-carbaldehyde to afford 3 m. The purified targeted products 3a–m were effectively characterized for structural authentication using physicochemical parameters, microanalytical data, and spectroscopic methods, including IR, UV, and 1H- and 13C-NMR, as well as mass spectral data. The substituted arylidene-based quinazolin-4(3H)-one motifs 3a–m were screened for both in silico and in vitro antimicrobial properties against selected bacteria and fungi. The in silico studies carried out consisted of predicted ADMET screening, molecular docking, and molecular dynamics (MD) simulation studies. Furthermore, in vitro experimental validation was performed using the agar diffusion method, and the standard antibacterial and antifungal drugs used were gentamicin and ketoconazole, respectively.Results and discussion: Most of the compounds possessed good binding affinities according to the molecular docking studies, while MD simulation revealed their levels of structural stability in the protein–ligand complexes. 2-methyl-3-((thiophen-2-ylmethylene)amino) quinazolin-4(3H)-one 3 m emerged as both the most active antibacterial agent (with an minimum inhibitory concentration (MIC) value of 1.95 μg/mL) against Staphylococcus aureus and the most active antifungal agent (with an MIC value of 3.90 μg/mL) against Candida albicans, Aspergillus niger, and Rhizopus nigricans

A diverse view of science to catalyse change

Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions

A diverse view of science to catalyse change:Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. we must value diversity not only in words, but also in actions

No abstract available.publishe

Quinazoline pharmacophore in therapeutic medicine

This present study comprehensively expatiates the functionalized utilization of quinazoline scaffolds in drug development and furnishes latest updates in pharmacological appositeness of its derivatives in order to reveal novel pathways for therapeutic targets. It traverses numerous biological potentials of quinazoline in the contemporary time to allow researchers’ unhindered access to the beneficial role of quinazoline in fighting infectious diseases for future drug discovery. This work provides broad overview of medicinal survey of quinazoline chemistry valuable in the discovery of more efficient clinical trials and to summarize the most promising molecular targets for drug design

Quinazoline pharmacophore in therapeutic medicine

This present study comprehensively expatiates the functionalized utilization of quinazoline scaffolds in drug development and furnishes latest updates in pharmacological appositeness of its derivatives in order to reveal novel pathways for therapeutic targets. It traverses numerous biological potentials of quinazoline in the contemporary time to allow researchers unhindered access to the beneficial role of quinazoline in fighting infectious diseases for future drug discovery. This work provides broad overview of medicinal survey of quinazoline chemistry valuable in the discovery of more efficient clinical trials and to summarize the most promising molecular targets for drug design. 

Structure-based design of functionalized 2-substituted and 1,2-disubstituted benzimidazole derivatives and their in vitro antibacterial efficacy

The aim of this present study was to synthesize 2-substituted and 1,2-disubstituted benzimidazole derivatives to investigate their antibacterial diversity for possible future drug design. The structure-based design of precursors 2-(1H-benzimidazol-2-yl)aniline 1, 2-(3,5-dinitro phenyl)-1H-benzimidazole 3 and 2-benzyl-1H-benzimidazole 5 were achieved by the condensation reaction of o-phenylenediamine with anthranilic acid, 3,5-dinitrophenylbenzoic acid, and phenylacetic acid, respectively. The precursors 1, 3 and 5, upon reaction with six different electrophile-releasing agents, furnished the corresponding 2-substituted benzimidazole, 2a-f and 1,2-disubstituted benzimidazole derivatives 4a-f and 6a-f, respectively. The structural identity of the targeted compounds was authenticated by elemental analytical data and spectral information from FT-IR, UV, 1H, and 13C NMR. The outcome of the findings from the in vitro screening unveiled 2-benzyl-1-(phenylsulfonyl)-1H-benzimidazole 6b as the most active derivative with lowest MIC value of 15.63 µg/mL