Researches on taxane-type compounds of Taxus baccata growing in Turkey

7. ABSTRACT Taxol, a diterpenoid with a taxane-type structure was first isolated from the bark of the Pacific Yew Tree (Taxus brevifolia L.) and was found to be a new class of microtubule-stabilizing anticancer agent used in chemotherapy. The woods of thick branches of the European Yew Tree {Taxus baccata L.) growing in Turkey were found to be rich in taxoid content than the other parts of plant220. Investigation of the taxane-type constituents of Taxus baccata L. (Taxaceae) recorded in the Flora of Turkey, collected from Rize-Çamlıhemşin is presented. As a result of the isolation and purification procedures, 14 compounds were obtained and their structures were elucidated by extensive spectroscopic analysis primarily by two-dimensional NMR techniques. They are; 10-Deacetylbaccatin m* (T-2), Baccatin HI (TB-6), Baccatin VI (TB-5) and Taxol (TB-8) from the oxetane-bearing; 2a,5a.l0p-Triacetoxy-14p-(2-methyl)-butnio.\y-4(20),ll-taxadiene (TB-2) and Taxusin (TB-3) from the exocylic-containing; and lp-Hydroxy baccatin I (TB-7) from the epoxide-bearing taxoids were determined from the woods of thick branches of T. baccata L. growing in Turkey. Among these, taxusin and baccatin III were found to be major compounds. In addition, six phenolic compounds namely, 3-Methoxy-4- hydroxycinnamaldehyde (TB-4), Lariciresinol (TB-9), Isolariciresinol (TB-10), 3'-Demethylisolariciresinol-9'-hydroxyisopropylether (TB-1 1), 3'-DemethyllariciresinoI (TB-1 2) and 3-DemethylisoIariciresinol (TB-1 3) were also isolated along with taxoids. During phytochemical studies, ^-sitosterol (TB-1) was obtained as well. "It was obtained from the fleshy barks of the thick branches of T. baccata L.224 This is the first report of the taxoid content of the wood of the European Yew Tree (T. baccata L). Besides, the presence of the above mentioned phenolic compounds except isolariciresinol in the genus, Taxus are being provided for the first time in this research as well as their extensive spectroscopic data. Key Words: Taxus baccata, Taxaceae, Taxoid, Spectral data