Three novel bicyclic 3,8-secotaxane diterpenoids from the needles of the Chinese yew, Taxus chinensis var. mairei

Abstract

Three novel (1-3) and five known bicyclic 3,8-secotaxane diterpenoids were isolated from the needles of the Chinese yew, Taxus chinensis var. mairei. The structures of the new compounds were established, respectively, as (3E,7E)-2α,10β,13α-triacetoxy-5α,20-dihydroxy-3,8-secotaxa-3,7,11- trien-9-one (1), (3E,7E)-2a* 10β-diacetoxy-5α, 13α,20-trihydroxy-3,8- secotaxa-3,7,11-trien-9-one (2), and (3E,8E)-7β,9,10β,13α,20- pentaacetoxy-3,8-secotaxa-3,8,11-triene-2α,5α-diol (2- deacetyltaxachitriene A) (3), on the basis of spectral analysis. The other five bicyclic taxane diterpenoids were determined as canadensene, 5- deacetyltaxachitriene B, taxachitriene B, taxuspine U, and taxuspine X by comparison of their physical properties and spectral data with those previously reported.