A New pseudo-Alkaloid Taxane and a New Rearranged Taxane from the Needles of Taxus canadensis

A new taxane with an amino side chain on C-5 and a new 11(15→1)abeotaxane having a tetrahydrofuran ring along carbon atoms C-2, C-3, C-4, C-20 identified for the first time from the needles of the Canadian yew, Taxus canadensis. Their structures were characterized as 2α,7β ,9α,10β ,13-pentaacetoxy-11β -hydroxy-5α-(2 -hydroxy,3 -N,N-dimethylamino-3 -phenyl)-propionyloxytaxa-4(20),12-diene (1) and 13α,20β -diacetoxy-5α,7β ,9α,10β -tetrahydroxy-2α,20-epoxy-11(15→1)abeotaxa-11,15-diene (2) on the basis of 1D, 2D NMR spectroscopy and high-resolution FABMS analysis. Taxane 1 contains a rare C-12, C-13 double bond and a basic side chain, while taxane 2 bears a rare isopropenyl group at C-1