1-Deoxypaclitaxel and abeo-Taxoids from the Seeds of Taxus mairei

Abstract

A new paclitaxel derivative and two new 2(3-->20)-abeo-taxoids were isolated from a methanol extract of the seeds of Taxus mairei, and their structures were established as 1-deoxypaclitaxel (1), 7beta,10beta-diacetoxy-2alpha,5alpha,13alpha-trihydroxy-2(3-->20)-abeo-taxa-4(20),11-dien-9-one (2), and 2alpha,13alpha-diacetoxy-10beta-hydroxy-2(3-->20)-abeo-taxa-4(20),6,11-triene-5,9-dione (3) on the basis of spectroscopic data analysis. Taxane 1 is the first example of a paclitaxel analogue with a C-1beta hydrogen substituent. Taxane 3 is an 2(3-->20)-abeo-taxane with a rare C-5 ketone and C-6 double bond.

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.…”

Anti-proliferative and apoptosis-inducible activity of labdane and abietane diterpenoids from the pulp of Torreya nucifera in HeLa cells

“…We are now isolating other diterpenoids from various plants, particularly from Taxus mairei (33), and searching for novel diterpenoids that have greater anti-proliferative activity in human cancer cells than kayadiol.…”

Synthesis, cytotoxic activity, and SAR analysis of the derivatives of taxchinin A and brevifoliol

“…1,2 Most of modification and study of SAR of taxoids were focused on paclitaxel and its analogs with 6/8/6 skeleton and an oxetane ring. 1)-abeo-taxoids with 5/7/6 skeleton.…”