New cathepsin V inhibitor from stems of Bowdichia virgilioides

Abstract Bioassay-guided fractionation of Bowdichia virgilioides Kunth, Fabaceae, extracts has led to the isolation of cathepsin V inhibitors. The investigation of the hexane and ethyl acetate extracts allowed the characterization of eleven compounds: lupeol, lupenone, β-sitosterol and stigmasterol in mixture, trans p-coumaric acid ester derivative, syringaresinol, bowdenol, 8-methoxycoumestrol, 3,4-hydroxy-7-methoxyisoflavone, 7,3′-dihydroxy-4′-methoxyisoflavone, and 5,4′-dihydroxy-7′-methoxyisoflavone. Structures of compounds were stablished by 1D and 2D NMR, and MS experiments. Among the isolated compounds, trans p-coumaric acid ester derivative and 8-methoxycoumestrol showed significant inhibition on cathepsin V, which is up to now unexplored.