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), 7β,10β- diacetoxy-2α,5α,13α-trihydroxy-2(3→20)-abeo-taxa-4(20), 11-dien-9-one (2), and 2α,13α-diacetoxy-10α-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-1β hydrogen substituent. Taxane 3 is an 2(3-→20)-abeo-taxane with a rare C-5 ketone and C-6 double bond.