Through bioassay-guided separation of the chemical constituents of the needles of Taxus sumatrana, taxol (1), cephalomannine (2), and a new taxoid 19-hydroxy-13-oxobaccatin III (8) have been isolated together with 7-epi-10-deacetyltaxol (3), 7-epi-10-deacetylcephalomannine (4), baccatin III (5),