No abstract

The genus Cassia is a significant source of secondary metabolites that are physiologically active and come from several chemical classes. The current research deals with the isolation, spectroscopic elucidation (1D and 2D NMR spectroscopy) and enzymatic activity of fifteen known compounds as well as a new unidentified avenasterol derivative namely 21-methylene-24-ethylidene lophenol. The urease and β-glucosidase inhibitory effects of these compounds were studied for the first time, and molecular docking studies were also performed to verify the structure-activity relationships. All the compounds evaluated towards urease showed higher inhibitory activity (1.224±0.43 < IC50 > 6.678±0.11 μM) compared to standard thiourea (IC50 = 18.61±0.11 μM). Molecular docking results revealed that compound 7 strongly inhibits urease due to the formation of a stable ligand-urease complex via hydrogen bonding, van der Waal and hydrophobic interactions. Formation of a favorable complex of 7 with the target enzyme gave a more negative docking score (-6.95 kcal/mol) than that of thiourea (-3.13 kcal/mol). Regarding the β-glucosidase enzyme, all the compounds evaluated did not show activity except compound 1 which inhibited the latter with a percentage of inhibition of 82.6. These findings imply that this plant may be a contender for developing novel treatments for infectious disorders brought on by urease-producing bacteria.