title: Norsesquiterpene derivatives from the roots of Ligularia fischeri.
abstract: Four new norsesquiterpene derivatives with various rare skeletons: 1 beta-hydroxy-6 alpha-isobutyryloxy-9-noreremophil-7(11),8(10)-dien-8(12)-olide ( 1), 1 beta-acetoxy-6 alpha-isobutyryloxy-9-noreremophil-7(11),8(10)-dien-8(12)-olide ( 2), ligularate ( 3) and 9-oxoplatyphyllide ( 4), as well as four known sesquiterpenes, platyphyllide ( 5), 1-hydroxyplatyphyllide ( 6), 1 alpha-chloro-6 beta-isobutyryloxy-9-oxo-10 beta-hydroxyfuranoeremophilane ( 7), and 1 alpha-chloro-6 beta-angeloyloxy-9-oxo-10 beta-hydroxyfuranoeremophilane ( 8), have been isolated from an extract of the dried roots of Ligularia fischeri (Compositae). The structures of the new compounds were established by spectroscopic methods including extensive 2D NMR techniques ( (1)H- (1)H COSY, HMQC, HMBC and (1)H- (1)H NOESY) and HR-ESI-MS. In addition, a plausible biosyntheticpathway for compounds 1, 2 and 3 is described.
authors: Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, PR China.
authors: Wen-Juan
authors: WJ
authors: Zhang
authors: Huan-Yang
authors: HY
authors: Qi
authors: Yan-Ping
authors: YP
authors: Shi
mesh_terms: D019659:Asteraceae / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D010936:Plant Extracts / Q000096:biosynthesis / Q000737:chemistry*; D018517:Plant Roots; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D010936:Plant Extracts; D012717:Sesquiterpenes