Isolation and structural identification of taxanes in Taxus yunnanensis

Object To intensively investigate taxane diterpenes in Taxus yunnanensis Cheng et L K Fu growing in Yunnan Province of China Methods The needles and twigs of the plant were extracted with ethanol, the ethanol extract was subjected to extraction with methylene dichlorid, the methylene dichlorid extract was submitted to chromatography on silica gel column to isolate some compounds The obtained compounds were purified by PTLC and preparative HPLC, and their structures were elucidated on the basis of spectral analysis (UV, IR, ESI MS, 1HNMR, 13 CNMR) Results Five taxane diterpenes were isolated and identified as l acetoxy baccatin Ⅰ(Ⅰ), 7 epi taxol (Ⅱ), taxchinin A (Ⅲ), cephalemannine (Ⅳ) and taxol (Ⅴ) Conclusion Compound Ⅰ is new, Ⅱ and Ⅲ are isolated from T Yunnnanensis for the first time