title: Four new epoxy taxanes from needles of Taxus cuspidata (Taxaceae).
abstract: Four new epoxy taxoids were isolated from the needles of Taxus cuspidata. Their structures were established as 2a,9a-diacetoxy-5a-cinnamoyloxy-11,12-epoxy-10ss-hydroxytax-4(20)-en-13-one (1), 2a,10ss-diacetoxy-5a-cinnamoyloxy-11,12-epoxy-9a-hydroxytax-4(20)-en-13-one (2), 2a,9a-diacetoxy-11,12-epoxy-10ss,20-dihydroxytax-4-en-13-one (3) and 2a,10ss-diacetoxy-11,12-epoxy-9a,20-dihydroxytax-4-en-13-one (4) on the basis of spectral analysis including 1H-NMR, 13C-NMR, 1H-1H-COSY, HSQC, HMBC and HRFABMS. Compounds 3 and 4 are the first example of 11,12-epoxy taxoids with C-4 double bond found in T. cuspidata.
authors.affiliation: Department of Natural Product Chemistry, School of Pharmaceutical Sciences, Hebei Medicinal University, 336 Zhongshan East Road, 050017, Shijiazhuang, Hebei Province, People's Republic of China.
authors.forename: Qing-Wen
authors.initials: QW
authors.lastname: Shi
authors.forename: Cong-Mei
authors.initials: CM
authors.lastname: Cao
authors.forename: Ji-Shun
authors.initials: JS
authors.lastname: Gu
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Kiyota
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*; D043823:Taxoids / Q000737:chemistry / Q000302:isolation & purification*; D020946:Taxus / Q000737:chemistry*
chemical_list: D043823:Taxoids