Taxanes from Rooted Cuttings of Taxus c anadensis

A 3,11-cyclotaxane (1), a new epoxytaxane (2), an abeo-taxane (3), and 26 known taxanes were isolated in rooted cuttings of the Canadian yew (Taxus canadensis) for the first time. Their chemical structures were characterized as 1β,2α,9α-trihydroxy-10β-acetoxy-5α-cinnamoyloxy-3,11-cyclotaxa-4(20)-en-13-one (1), 2α,9α,10β-triacetoxy-11,12-epoxy-20-hydroxytaxa-4-en-13-one (2), and 7β,9α,10β,13α-tetraacetoxy-11(15→1)abeo-taxa-4(20),11-diene-5α,15-diol (3). Metabolite 2 is a new taxane, metabolite 1 has been reported previously in the needles of Taxus baccata, , and metabolite 3 was previously discovered as a biotransformation product but is now reported as a natural product for the first time.