Novel taxa-4(20),12-diene and 2(3→20)abeotaxane from needles of Taxus canadensis

Abstract

A novel 6/8/6-membered taxane with a rare C-12(13)-double bond and rare 2(3→20)abeotaxane were isolated from the needles of Taxus canadensis. Their structures were characterized as 7β,9α,10β-triacetoxytaxa- 4(20),12-diene-2α,5α,11β-triol (1) and 2α,7β, 10β- triacetoxy-5α-hydroxy-2(3→20)abeotaxa-4(20),11-diene- 9,13-dione (2) on the basis of 1D and 2D spectroscopic data. 1 is the first example of a natural taxane without substitution at both C-13 and C-14.