New bicyclic taxane diterpenoids from Taxus sumatrana

Investigation of an acetone extract of the leaves and twigs of, Taxus sumatrana has resulted in the isolation of two new bicyclic taxoids, tasumatrols M (1), and N (2) and a new baccatin III derivative, tasumatrol O (3) together with the previous known 7-deacetylcanadensene (4) and 2 alpha,7 beta,13 alpha-triacetoxy-5 alpha,9 alpha-dihydroxy-2(3 -> 20) abeotaxa-4(20),11-dien-10-one. The structures of these taxanes were established on the basis of spectroscopic analyses, especially 1- and 2D NMR, and chemical derivatization.