Dantaxusins A and B, two new taxoids from Taxus yunnanensis.

Two new taxane diterpenes, dantaxusin A [5α-cinnamoyloxy-2α,7β,13α-triacetoxy-2(3→20)abeo-taxa-4(20),11-diene-9,10-dione (1)] and dantaxusin B [5α-cinnamoyloxy-9α-hydroxy-10β,13α-diacetoxytaxa-4(20),11-diene (2)], were isolated from an ethanol extract of the aerial parts of Taxus yunnanensis along with taxuspine B, 2-deacetoxytaxinine J, taxuyunnanine C, taxinine B, taxuspine C, and taxinine NN-4. The structures of 1 and 2 were established on the basis of 1D and 2D NMR and HRMS spectroscopic methods.