Triterpenes from Astilbe chinensis.

Six new triterpenes, 3beta,6beta-dihydroxyurs-12-en-27-oic acid (1), 3beta,6beta,24-trihydroxyurs-12-en-27-oic acid (2), 3beta,6beta,7alpha-trihydroxyurs-12-en-27-oic acid (3), 3beta-acetoxy-6beta-hydroxyurs-12-en-27-oic acid (4), 3beta,6beta,24-trihydroxyolean-12-en-27-oic acid (5), and 3beta,6beta,7alpha-trihydroxyolean-12-en-27-oic acid (6), were isolated from the rhizomes of Astilbe chinensis. Their structures were elucidated on the basis of 1D- and 2D-NMR analyses and HR-MS experiments. The isolated compounds exhibited significant cytotoxic activities against the SK-N-SH and HL-60 cell lines.