alkaloid biosynthesis taxol biosynthesis GO:0042617 PMID:11524108 UPa:UPA00842 pathway KEGG:map00904 paclitaxel biosynthesis KEGG:map01100 KEGG:map01110 Biosynthesis of the diterpenoid taxol (generic name paclitaxel). Paclitaxel is a highly effective anticancer drug used widely in the treatment of various carcinomas, melanomas, and sarcomas. This structurally complex taxane diterpenoid (taxoid) was first isolated from the bark of the Pacific yew (Taxus brevifolia Nutt.).