lSOLATlON AND STRUCTURAL ELUClDATION OF FOUR NEW TAXANE DITERPENOlDS FROM TAXUS YUNNANENSIS

Seven taxane diterpen oids and alk aloids have been isolated from the ethanolicextract of the bark of Taxus yunnanensis Cheng et L.K.Fu. Three were identified as the known taxanes:5-decinnamovyl taxinineJ ( III),7-xylosyl taxol(V)and 7-xylosyl cephalomannine(VI ).Thestructures of four new compounds were elucidated as 5- decinnamoyl-11-acetyl-19- hydroxy taxagifine(I),2- deacety-5- decinnamoyltaxinine J(II ,1-hydroxy-2,7,9-trideacetylbaccatin I(IV )and7- xylosyl-10- deacetoxybaccatin III(VII)by spectroscopic methods(MS,¹H NMR,¹H-¹H COSY,¹³CNMR, ¹³C-¹HCOSY).