Synthesis and Antimicrobial Activities of 2H-Chromene-3-Carboxamide Derivatives: Experimental and Computational Studies
T.O. Olomola, L.O. Olasunkanmi, J.O. Fadakinni, A.J. Akinboye, T.O. Kelani, and O.O. Olasunkanmi (pp. 64-77)
Abstract
Coupling reaction between Baylis–Hillman-derived 2H-chromene-3-carboxylic acid derivatives and some amines afforded the corresponding 2H-chromene-3-carboxamides. The synthesized carboxamides and their acid precursors were screened for their in vitro antifungal and antibacterial activities using nystatin and streptomycin, respectively, as standard drugs. Among the tested compounds, it has been found that compounds 3a, 3c, and 4c (minimum inhibitory concentration = 0.062 mg/mL) exhibited better activities than the reference drug, streptomycin (minimum inhibitory concentration = 0.125 mg/mL) against Bacillus cereus. Compound 4a showed the best inhibitory profile against gram-negative bacterial strains, while compound 4b appeared to be the most active against fungal strains Candida albicans and Aspergillus niger. Molecular quantum chemical calculations suggested that the activities of the compounds against gram-negative bacterial strains could have some correlations with the electron-donating abilities of the molecules, while their activities against gram-positive bacterial strains showed some correlations with the electron-accepting abilities of the molecules.