10-Deacetyl Baccatin III (syn: 10-DAB) is a natural organic compound produced by the Pacific Yew tree. It is used as a key backbone intermediate for the semi-synthesis of Paclitaxel (Taxol), an anti-cancer drug and Docetaxel and their analogs. It is used to study the biosynthetic pathway of Taxol. The trunk and leaves contain the highest concentration of 10-Deacetyl Baccatin III, but it may be found in parts of the Yew tree.