1-deoxypaclitaxel and abeo-taxoids from the seeds of Taxus mairei.

A new paclitaxel derivative and two new 2(3-->20)-abeo-taxoids were isolated from a methanol extract of the seeds of Taxus mairei, and their structures were established as 1-deoxypaclitaxel (1), 7beta,10beta-diacetoxy-2alpha,5alpha,13alpha-trihydroxy-2(3-->20)-abeo-taxa-4(20),11-dien-9-one (2), and 2alpha,13alpha-diacetoxy-10beta-hydroxy-2(3-->20)-abeo-taxa-4(20),6,11-triene-5,9-dione (3) on the basis of spectroscopic data analysis. Taxane 1 is the first example of a paclitaxel analogue with a C-1beta hydrogen substituent. Taxane 3 is an 2(3-->20)-abeo-taxane with a rare C-5 ketone and C-6 double bond.