Click-chemistry-inspired synthesis of new series of 1,2,3-triazole fused chromene with glucose triazole conjugates: Antibacterial activity assessment with molecular docking evaluation.

A series of new 1,2,3-triazole fused chromene based glucose triazole conjugates were synthesized from chromene fused 1,2,3-triazolyl extended alkyne and 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl azide in good to excellent yield by a copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The major advantages include mild reaction conditions, high yield, good substrate scope, and shorter reaction time. The antibacterial efficacy of the compounds were assessed in vitro against human pathogenic Gram-negative E. coli and Gram-positive S. aureus bacteria. Compound 24j was found to be the most potent molecule with zone of inhibition (ZI) of 17 mm and minimum inhibitory concentration (MIC) of 25 μg mL in E. coli and ZI of 16 mm and MIC of 25 μg mL in S. aureus. Also, it significantly inhibited E. coli DNA-gyrase in silico with a binding affinity of -9.4 kcal/mol. Among all the synthesized compounds, 24i, 24d, 24e and 24f showed significant antibacterial activity against both strains and inhibited DNA-gyrase in silico with good binding affinities. Hence, these 1,2,3-triazole fused chromene based glucose triazole conjugates may evolve to be powerful antibacterial agents in recent future, according to structure-activity relationships based on strong antibacterial properties and molecular docking studies.