Ping Hai, Shi-Zhen Wen, Yan Li, Yuan Gao, Xian-Jun Jiang, Fei Wang
Three hitherto unknown taxane diterpenoids, namely baccatin VIII(1), baccatin IX(2), and baccatin X(3), along with 10 known analogues were isolated from an ethanolic extract of the twigs and leaves of Taxus yunnanensis. The new structures were characterized based on extensive spectroscopic analysis. Compounds 1 and 2 were tested for their in vitro cytotoxicity against five human tumor cell lines, and 1 exhibited inhibitory effects on HL-60 and MCF-7, with IC50 values of 3.44 and 9.67 μM, respectively.