title: abeo-taxane diterpenoids from the Taiwanese Yew Taxus sumatrana.
abstract: Chemical investigation of the acetonic extract of the leaves and twigs of Taxus sumatrana (Taxaceae) led to the isolation of four new taxane diterpene esters, taiwantaxins A-D (1-4, resp.). Their structures were determined primarily on the basis of 1D- and 2D-NMR techniques as well as MS. Compound 1 is a rearranged taxane diterpenoid possessing an opened oxetane ring moiety containing C(4), C(5), and C(20). The metabolites 2 and 3 belong to a 5/6/6 taxene system having a rare five-membered gamma-lactone ring comprising C(8), C(9), C(10), and C(19). Compound 4 is an example of a taxane diterpene containing a 6/8/6 ring system with a tetrahydrofuran ring comprising C(2), C(3), C(4), and C(20). The 11(15-->1)abeo-taxane diterpenoids, taiwantaxins A-C (1-3, resp.) are lacking an O-bearing functionality at either C(13) or C(14). Compound 2 showed significant cytotoxic activity against human PC-3 tumor cells.
authors.affiliation: Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 804, R.O.C.
authors.forename: Shih-Sheng
authors.initials: SS
authors.lastname: Wang
authors.forename: Mohamed H
authors.initials: MH
authors.lastname: Abd El-Razek
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Chen
authors.forename: Ching-Te
authors.initials: CT
authors.lastname: Chien
authors.forename: Jih-Hwa
authors.initials: JH
authors.lastname: Guh
authors.forename: Yao-Haur
authors.initials: YH
authors.lastname: Kuo
authors.forename: Ya-Ching
authors.initials: YC
authors.lastname: Shen
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D001952:Bridged-Ring Compounds / Q000737:chemistry*; D045744:Cell Line, Tumor; D004224:Diterpenes / Q000737:chemistry*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D018515:Plant Leaves / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D013624:Taiwan; D043823:Taxoids / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity*; D020946:Taxus / Q000737:chemistry*
chemical_list: C547375:5a-acetoxy-20-(benzoyloxy)-2a,4a,7b,9a,15-pentahydroxy-10- oxo-10,19-epoxy-11(15-1)abeo-tax-11(12)-ene; D000972:Antineoplastic Agents, Phytogenic; D001952:Bridged-Ring Compounds; D004224:Diterpenes; D043823:Taxoids; C080625:taxane