Chemical constituents from the stems of Picrasma quassioides Bennet / 中国药科大学学报

The phytochemical studies on the stems of Picrasma quassioides Bennet led to the isolation of seven β-carboline alkaloids (1-6),five cantin-6-one alkaloids (7-11),two canthin-5,6-dione (12,13),three sesquiterpe nes (14-16),and one steroids (17).Their structures were elucidated by the combination of spectroscopic analyses (ESI-MS,1H NMR and 13C NMR) and the comparisons with the reference.Compound 16 is a new natural product,and this is the first report for compounds 5,6,14-17 from the species P.quassioides.