Taxumairols X—Z, New Taxoids from Taiwanese Taxus mairei

Abstract

In addition to 19-dydroxybaccatin III, 1β-hydroxy-5α-deacetylbaccatin I, taxayuntin G and 13-O-deacetyltaxumairol Z (4), three new taxane diterpenoids, taxumairols X (1), Y (2), Z (3) have been isolated from extracts of the Formosan Taxus mairei (LEMEE & LEVL.) S. Y. HU. Compounds 1—2 belong to the 11(15→1)-abeo-taxane system, having a tetrahydrofuran ring at C-2, C-3, C-4 and C-20. The new compound 3 and 4, which was misidentified previously are derivatives of 11(15→1)-abeo-taxane with an intact oxirane system. The structures of compounds 1—4 were elucidated on the basis of extensive two dimensional (2D)-NMR analysis.