Li_2026_Chem.Biodivers_23_e71552

To discover novel potential enzyme inhibitors based on natural products, a series of N-acyl pregnane alkaloid ester derivatives were designed, synthesized, and evaluated for their inhibitory activity against acetylcholinesterase (AChE) and alpha-glucosidase. The bioassay test results revealed that the target compounds generally showed more potent inhibition against alpha-glucosidase than against AChE. Notably, compounds 6e and 6i demonstrated significant alpha-glucosidase inhibitory activity, with IC(50) values of 29.85 microM and 38.11 microM (acarbose IC(50): 16.49 microM), respectively, and exhibited low cytotoxicity toward Thle-2 cells, with IC(50) values of 112.70 microM and 73.65 microM, respectively. Structure-activity relationship (SAR) analysis indicated that derivatives bearing an N-tigloyl group and nitro or pyridine substituents at the C-20 position contributed to enhanced alpha-glucosidase inhibition. Enzyme kinetics confirmed that 6e and 6i function as reversible, noncompetitive inhibitors of alpha-glucosidase. Molecular docking studies further illustrated that both compounds bind to the lateral surface of the alphaglucosidase through hydrogen bonds and hydrophobic interactions, rather than occupying the catalytic active site. These findings highlight that 6e and 6i exhibit certain inhibitory activity, providing a basis for the design of subsequent derivatives.