Three Novel Bicyclic 3,8-Secotaxane Diterpenoids from the Needles of the Chinese Yew, Taxus chinensis var. mairei

Abstract

Three novel (1-3) and five known bicyclic 3,8-secotaxane diterpenoids were isolated from the needles of the Chinese yew, Taxus chinensis var. mairei. The structures of the new compounds were established, respectively, as (3E,7E)-2alpha,10beta, 13alpha-triacetoxy-5alpha,20-dihydroxy-3,8-secotaxa-3,7, 11-trien-9-one (1), (3E,7E)-2alpha,10beta-diacetoxy-5alpha,13alpha, 20-trihydroxy-3,8-secotaxa-3,7,11-trien-9-one (2), and (3E,8E)-7beta, 9,10beta,13alpha,20-pentaacetoxy-3,8-secotaxa-3,8,11-triene-2alpha, 5alpha-diol (2-deacetyltaxachitriene A) (3), on the basis of spectral analysis. The other five bicyclic taxane diterpenoids were determined as canadensene, 5-deacetyltaxachitriene B, taxachitriene B, taxuspine U, and taxuspine X by comparison of their physical properties and spectral data with those previously reported.

Canadensenes: Natural and semi-synthetic analogues

“…Taxanes 4 and 5 were characterized as 2-deacetyltaxachitriene A and 13,20-dideacetyltaxachitriene A, respectively. They had been previously identified in Taxus mairei needles (10,11). Taxane 6 was identical to 5-deacetyltaxachitriene B previously isolated with taxachitriene B in T. chinensis needles (8,9).…”

“…1) in 1995 and 1998, respectively, to emphasize their origin (6, 7). Simultaneously, taxachitrienes 3-6 were reported in the needles of the Chinese and in the stems of the Japanese yews (8)(9)(10)(11).…”

Chemical Studies on Taxus cuspidata

“…3,8-Secotaxanes were first reported simultaneously in 1995 from Chinese yew, T. chinensis [98], and Canadian yew, T. canadensis [99], independently. Later, this class of taxanes is also isolated from T. mairei [100] and T. cuspidata [28]. So far, five bicyclic taxanes (154 -158) are isolated from T. cuspidata.…”

Oxygenated verticillene derivatives from Bursera suntui

“…These metabolites have been isolated from diverse sources such as the conifer Sciadopitys verticillata (Karlsson et al, 1978), the yew trees Taxus canadensis (Zamir et al, 1995(Zamir et al, , 1998, T. cuspidata (Renzulli et al, 2004), T. chinensis (Fang et al, 1995), T. chinensis var. mairei (Shi et al, 1998), and T. mairei (Shi et al, 2005), as well as the soft corals Cespitularia hypotentaculata (Duh et al, 2002) and C. taeniata (Shen et al, 2005), antipodal structures have also been found in the liverworts Jackiella javanica and Jungermannia infusca (Nagashima et al, 1997(Nagashima et al, , 2005. Some verticillene derivatives display relevant biological activity against diverse tumour cell lines; for example, verticillenes isolated from Taxus sp.…”