STUDIES ON THE CHEM ICAL CONSTITUENTS OF LEAVES AND TW IGS OF TAXUS CUSPJDlATA

The methylene chloride extract Of the leaves and twigs of Taxus cuspidata Sieb etZucc which grows in the northeast of China ,showed inhibitory effect on human tumor cells.Fromthis extract we have isolated twelve compounds belong to the taxane diterpenoid series.Among themten compounds were identified as taxinine(I),taxinine A(II),taxinine B(III) ,taxacin(V),taxa-gifine(Vl),taxol(Vll),cephalomannine(VIII),taxinine M(IX),10-deacetyl baccatin III(X)andtaxayuntin(XI).The latter five compounds were isolated from this plant for the first time. The othertwo compounds are new taxane diterpenes——named 1O-deacetyl taxinine B(IV)and taxacustin(XII).Their structures were elucidated by spectrometric analyses and X-ray diffraction analysis.