ABSTRACT
Objective: To study the chemical constituents from the pericarpium of Metaplexis japonica. Methods: The petroleum ether, dichloromethane and ethyl acetate fractions of 95% ethanol extract from M. japonica were isolated and purified by silica gel, Sephadex LH-20, MPLC and preparative HPLC, etc. The structures of the obtained compounds were identified by physicochemical properties and spectral data. Results: Ten compounds were isolated and identified as (15β,21α)-dihydroxypregna-17,20-trimethylene oxide-4,6-dien-3-one (1), 25-hydroperoxycyc-loart-23-en-3β-ol (2), α-amyrin (3), scoparone (4), aleuritin (5), syringaresinol (6), pergularin-3-O-β-D-oleanodropyranose (7), (20β)-21-dihydroxypregna-4,6-dien-3-one (8), blumenol A (9) and 4-pregnen-20,21- diol-3-one (10). Conclusion: Compound 1 is a new C21 steroidal compound named metajapogenin F, compounds 2 and 10 are isolated from the genus Metaplexis for the first time, and compound 8 is isolated from this plant for the first time.