R. Kenchappa

Synthesis, Antimicrobial and Antioxidant Activity of Chalcone DerivativesContaining Thiobarbitone Nucleus

In this paper we reported the synthesis of novel series of 5-[1,3-bis (4- substituted phenyl) prop-2-en-1-ylidene]- 2-thioxodihydropyrimidine-4,6(1H, 5H)-diones (5a-k). The target compounds were synthesized by the Knoevenagel condensation of different chalcones (3a-k) with thiobarbituric acid using acetic acid as a catalyst in ethanol. These compounds were screened for their antimicrobial and antioxidant activities. From antimicrobial activity results it was found that compounds 5e, 5i and 5k displayed good antibacterial and antifungal activity against all tested strains. Further, the selected compounds were studied for docking using the enzyme, Glucosamine-6-phosphate synthase and the compounds 5a, 5e and 5k have emerged as an active antimicrobial agents with least binding energy (-4.52 and -4.41 kJ mol-1). Compounds 5c and 5f showed promising free radical scavenging and Fe+2 ion chelating activity.

Synthesis of a series of novel 2,5-disubstituted-1,3,4-oxadiazole derivatives as potential antioxidant and antibacterial agents

A series of novel 2,5-disubstituted-1,3,4-oxadiazole derivatives were synthesized and screened for their antimicrobial and antioxidant activities. The assay indicated that compounds 3c, 3d, and 3i exhibited comparable antibacterial and antioxidant activity with first-line drugs. The structure activity relationship and molecular docking study of the synthesized compounds are also reported.

Synthesis, antibacterial and antitubercular activity of novel Schiff bases of 2-(1-benzofuran-2-yl)quinoline-4-carboxylic acid derivatives

Novel Schiff bases of 2-(1-benzofuran-2-yl)quinoline-4-carboxylic acid derivatives 5a–5e were synthesized by the reaction of 2-(1-benzofuran-2-yl)quinoline-4-carbohydrazide 3 with substituted aromatic aldehydes 4a–4e in presence of catalytic amount of acetic acid. Reaction of methyl 2-(1-benzofuran-2-yl)-quinoline-4-carboxylate 2 with hydrazine hydrate upon refluxing in ethanol for 4 h gave the key intermediate, hydrazide compound 3. All newly synthesized compounds were characterized by IR, NMR and Mass spectra and screened for antibacterial and antitubercular activity. Among the tested compounds carbohydrazide 3 and the compounds 5a and 5e exhibited high activity against S. aureus and E. faecalis respectively with MIC 0.064 mg/mL. Compound 5e demonstrated significant activity against S. aureus and E. faecalis with MIC 0.064 mg/mL. The antibacterial tests revealed hydrazide derivative 3 sensitivity at 25 μg/mL, showing high activity among the synthesized compounds.

Synthesis and antimicrobial activity of fused isatin and diazepine derivatives derived from 2-acetyl benzofuran

Acetyl benzofurans 1a, 1b reacted with isatins 2a–2f in the presence of pyridine to give corresponding 3-[2-(1-benzofuran-2-yl)-2-oxoethyl]-3-hydroxy-1,3-dihydro-2H-indol-2-one derivatives 3a–3l. Dehydration of the latter in acidic media led to the corresponding α,β-unsaturated ketones 4a–4l. The structures of newly synthesized compounds 3a–3l and 4a–4l were established on the basis of analytical and spectral data. The synthesized compounds were screened for their antibacterial and antifungal activities. Compounds 5d, 5f, and 5h displayed excellent antimicrobial activity. The synthesized compounds were studied for docking on the enzyme, Glucosamine-6-phosphate Synthase.

Synthesis, characterization, and antimicrobial activity of new benzofuran derivatives

A novel series of (5-substituted-1-benzofuran-2-yl)(2,4-substituted phenyl)methanones (4a–4i) have been prepared by the Knoevenagel condensation of (5-substituted-1-benzofuran-2-yl)(2,4-substituted phenyl)methanone (3a–3i) with Meldrum’s acid. The structures of the synthesized compounds were characterized by different spectroscopic techniques. All newly synthesized compounds were screened for antimicrobial activity.