New taxanes from the seeds of Taxus mairei

Abstract

Two new taxoid metabolites were isolated from the methanol extract of the Taxus mairei seeds. Their structures were established as 2alpha-hydroxy-9alpha,10beta,13alpha-triacetoxy-5alpha-cinnamoyloxytaxa-11-en-4beta,20-epoxide (1) and 2'-acetyl taxol (2) on the basis of spectral analysis.

Isolation and cytotoxicity evaluation of taxanes from the barks of Taxus wallichiana var. mairei

“…Compared to 4-6 and 16, the introduction of an O-b-xylose in R 2 (7)(8)(9)(10)(11) or loss of the C-13 ester side chain (14-15) greatly decrease their activities, which is consistent with the reported SAR of taxol analogues. 27 Interestingly, despite of the general low activity, the O-b-xylose bearing compounds 7-11 reserved their anti-proliferative activity and showed selective cytotoxicity towards certain cancer cell lines.…”

“…8 Previous phytochemical studies on this plant have led to the isolation a number of taxanes, some of which showed significant cytotoxicity. [9][10][11][12][13][14] In our screening program aimed at the discovery of structurally unique and biologically significant taxanes from Taxus plants, a new taxane glucoside, 7b,9a,10b-triacetoxy-13a-hydroxy-5a-O-(b-D-glucopyranosyl) taxa-4(20),11-diene (1), and 14 known analogues ( Fig. 1), 2-deacetoxytaxinine J 15 (2), 2-deacetoxyaustrospicatine 16 (3), cephalomannine 17 (4), 10-deacetyl-7-epi-taxol 18 (5), taxol 19 (6), 7-xylosyl-10-deacetyl taxol 20 (7), 7-b-xylosyl-cephalomannine 20 (8), 7-b-xylosyl-taxol 20 (9), 7-b-xylosyl-10-deacetyl-cephalomannine 20 (10), 7-xylosyl-10-deacetyl taxol C 20 (11), taxinine M 21 (12), taxacin 22 (13), 10-deacetylbaccatin III 23 (14), and baccatin III 17,20 (15) were isolated from the barks of T. wallichiana var.…”