Triterpenoids from Schisandra propinqua var. propinqua

Four new triterpenoids, propindilactone T (1), propindilactone U (2), changnanic acid 3-methyl ester (3) and schipropinic. acid (4), together with five known ones (5-9), were isolated and identified from the stems and leaves of Schisandra propinqua var. propinqua; their structures were determined based on spectroscopic and mass spectrometric analyses. The absolute configuration of 1 was confirmed by X-ray analysis. Compounds 1, 2, and 4-9 were tested for their cytotoxic activities against five human tumor cell lines; all were inactive except for 8, which showed weak activity against some of the cell lines.