Tri‐ and Bicyclic Taxoids from the Taiwanese Yew Taxus sumatrana

Abstract

Five new taxoids, including a new 2(3 ! 20)-abeo-taxane with a 6/10/6-membered ring system and four 3,8-seco-taxanes having a 6/12-membered ring system, were isolated from an acetone extract of the leaves and twigs of the Taiwanese yew (Taxus sumatrana, Taxaceae). The structures were established as 2a,7b,10a-triacetoxy-5a-hydroxy-2(3 ! 20)-abeo-taxa-4(20),11-dien-9,13-dione (1), (3E,8E)-2a,9,10b, 13a,20-pentaacetoxy-7b-hydroxy-3,8-secotaxa-3,8,11-trien-5-one (2), (3E,8E)-2a,9,10b,13a,20-pentaacetoxy-5a,7b-dihydroxy-3,8-secotaxa-3,8,11-triene (3), (3E,8E)-9,10b,13a-triacetoxy-2a,7b,20-trihydroxy-5a-[(2E)-cinnamoyloxy]-3,8-secotaxa-3,8,11-triene (4), and (3E,8E)-2a, 5a,7b,9,10b,13a-hexaacetoxy-20-hydroxy-3,8-secotaxa-3,8,11-triene (5), respectively, on the basis 1D-and 2D-NMR spectral analyses. The in vitro cytotoxic activity of compounds 1 -5 against four human tumor cell lines, including HeLa (cervical epitheloid), WiDr (colon), Daoy (medulloblastoma), and Hep2 (liver carcinoma) tumor cells was evaluated. Whereas compounds 1 -3 were inactive, the novel taxanes 4 and 5 showed significant cytotoxicity.

Novel Taxa-4(20),12-diene and 2(3→20)Abeotaxane from Needles ofTaxus canadensis

“…14,15) Compound 2 was therefore unambiguously characterized as 2,7,10-triacetoxy-5-hydroxy-2(3!20)abeotaxa-4(20),11-diene-9,13-dione. It should be noted that the 10-epimer of 2 has recently been isolated from the bark of T. sumatrana, 17) in which the 1 H-NMR chemical shift of H-C(10) was significantly different ( 5.69 ppm, 6.43 ppm for 1).…”

“…The locations of the acetyl groups were deduced from the HMBC correlations of carbonyl carbons with corresponding protons. The signal at C 78.2, which showed long-range correlations with H-C(9), H-C(10), Me (16) and Me (17) in the HMBC experiment, was assigned to C (11), and a hydroxy group attached to C(11) was suggested by its chemical shift value and molecular formula. The olefinic carbon at C 132.5, which showed HMBC correlations with H-C (10) and Me(18), was assigned to C(12).…”

Recent Progress in the Chemistry and Biology of Paclitaxel (TaxolTM) and Related Taxanes

“…In 2009, four novel taxane diterpenoids (2.1.29-2.1.32) (Figure 8.6) possessing an unusual 6/12-membered ring system were discovered from an acetone extract of the leaves and twigs of Taxus sumatrana [30]. The preliminary in vitro biological evaluations revealed that taxoids 2.1.…”

Cytotoxic Activity of Taxus Sumatrana (Miq.) De Laub. Bark, Leaves, and Shoots on Hela, T47d, and McF-7/Her2 Cell Lines

“…The tasumatrols A-Z were reported isolated from leaves and twigs [10][11][12][13][14][15]. The leaves and twigs also isolated Taiwantaxins A-D isolated [16] and other chemical compounds [17,18]. Some of the isolated compounds reported have cytotoxic activities.…”

“…Some of the isolated compounds reported have cytotoxic activities. Among them are wallifoliol (KB and Hepa 59 T/VGH), taxuspine F, and 3, 6, 7, 10-deacetylbaccatin III (Hepa cells), tasumatrol F (A-498, NCI-H226, A549, and PC-3 tumor cells), Tasumatrols I and K (Hepa59T/VGH, NCI, HELA, DLD-1, and Med cell lines), tasumatrol P (HELA and Daoy tumor cells), tasumatrol Z (Hep2 cell line), and Taiwantaxin B (PC-3 tumor cells) [9][10][11][12][13][14][15][16][17]. The results of clinical studies also indicated that paclitaxelcontaining regimens on breast cancer patients provided additional benefits [19].…”