Abstract:To understand the chemical constituents of Swietenia macrophylla barks, nine compounds were isolated and purified from bark extracts by using silica gel, gel and MPLC. Based on the physicochemical properties and spectral data, their structures were identified as vanillic acid (1), scopoletin (2), physcion (3), 3,4,5-trimeth-oxyphenyl-β-d-glucopyranoside (4), (+)-catechin (5), (+)-5'-methoxy-isolariciresinol-9'-O-β-dxylopyranoside (6), lyoniresinol-9'-O-β-d-xylopyranoside (7), stigmasterol (8), stigmasterol-3-O-β-d-glucopyranoside (9). Except for compound 5, the remaining compounds were isolated from this plant for the first time. The cytotoxicity assay showed that none of the compounds had significant cytotoxic activities.