A new taxoid metabolite with an unusual double bond between C-13 and C-14 was isolated from the methanol extract of the hard wood of Taxus cuspidata. The structure was established as 2α,5α,7β ,9α,10β ,13β -hexaacetoxy-11β -hydroxyl-19β -benzoxytaxa-4(20),13-dien- 12,16-epoxide (1), named 5,13-diacetyltaxinine M-13-enol, on the basis of spectral analysis including 1H NMR, 13C NMR, HMQC, HMBC, NOESY and confirmed by HR-FAB-MS.
Two new phytoecdysteroids with a 20,22-acetal group were identified for the first time from the needles of the Canadian yew, Taxus canadensis. Their structures were characterized as ponasterone A 20,22-p-hydroxybenzylidene acetal (1) and ponasterone A 20,22-acetonide (2) on the basis of 1D, 2D NMR evidence and high-resolution FABMS analysis
Two new mexicanolide-type limonoids, named xylomexicanin A (1) and xylomexicanin B (2), were isolated from seeds of the Chinese mangrove Xylocarpus granatum. Their structures were elucidated on the basis of spectroscopic methods. Compound 1 exhibited antiproliferative activity against human breast carcinoma cells (KT), while 2 did not show inhibitory effects on eleven human tumour cell lines tested.
Two 11(15→1)abeotaxanes having a tetrahydrofuran ring along the carbon atoms C-2, C-3, C-4, C-20 were identified for the first time from the needles of the Canadian yew, Taxus canadensis. The compounds could be identified as 4α,10β,13α-triacetoxy-15-benzoyloxy-2α,20β- epoxy-11(15→1)abeotax-11-ene-5α,7β,9α-triol () and 4α,7β,9α,10β,15-pentaacetoxy-2α,20β- epoxy-11(15→1)abeotax-11-ene-5α,13α-diol (2) on the basis of 1D-, 2D-NMR evidence and high-resolution FABMS analysis. Compound 1 showed weak growth inhibitory activities against T-98 and MM1-CB cells in vitro.
A new taxane peroxide, 4α,10β,13α-acetoxy-2α-benzoyloxy-7β,9α-epidioxy-5β,20-epoxytax-11-en-1β-ol (1), was isolated and characterized for the first time in rooted cuttings of the Canadian yew, Taxus canadensis.
Ten 1,10-secoguaianolides were isolated from the flowers of Achillea millefolium. Their structures were determined on the basis of spectroscopic methods. Three of them (millifolides A-C) including two dimeric sesquiterpenoids exhibit new skeletons. Seco-tanapartholide A exhibited moderate cell growth inhibitory activity against the human cancer cell line MCF7WT (IC50 = 5.51 μm) in vitro.
Eight sesquiterpene lactones were isolated from the roots of Inula helenium and fl owers of I. japonica. Among them, isoalantolactone () and santamarine (6) exhibited significant growth inhibitory activities against gynecologic cancer cell lines, while others weakly inhibited the growth of the cell lines (IC50 ≤ 100 μM). In addition, 3 significantly inhibited the tumour growth of S180 tumour-bearing mice. Compounds 3 and 6 were not toxic to human embryonic lung fibroblast cells in vitro. These results demonstrated that the antitumour activities are closely related to the structures of the compounds, that is, an α-exomethylene- γ-lactone ring is necessary for these activities.