title: [Norisoprenoids from red alga Gymnogongrus flabelliformis].
abstract: OBJECTIVE
  To investigate the chemical constituents of the red alga Gymnogongrus flabelliformis Harv.
  
  
  METHODS
  Compounds were isolated by normal phase silica gel and Sephadex LH - 20 gel column chromatography and reverse phase HPLC. Their structures were elucidated by spectroscopic methods including MS, 1H-NMR, 13C-NMR. Cytotoxicity of the compounds was screened by using standard MIT method.
  
  
  RESULTS
  Five compounds were isolated from G. flabelliforrmis, their structures were identified as(3S, 6R, 7E)-( + )-3-hydroxyl-4, 7-mega-stigmadien-9-one (1), (3S, 5R, 6S, 7E)-(-)-3-hydroxy-5, 6-epoxy-7-megastigmene-9-one (2), (3S, 5S, 6R, 7E)-(+)3-hydroxy-5, 6-epoxy-7-megastigmene-9-one (3), dehydrovomifoliol (4), (3R)-(-)4-[(2R, 4S)-4-acetoxy-2-hydroxy-2, 6, 6-trimethylcyclohexylidene] -3-buten-2-one (5).
  
  
  CONCLUSIONS
  All of the compounds were obtained from this species for the first time and compound 1 was a new natural product. These compounds were inactive (IC50 > 10 microg x mL(-1)) in the MTT assay against several human cancer cell lines.
authors.affiliation: Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Yuan
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Han
authors.forename: Xiao
authors.initials: X
authors.lastname: Fan
authors.forename: Shuai
authors.initials: S
authors.lastname: Li
authors.forename: Ming
authors.initials: M
authors.lastname: Ma
authors.forename: Yong-Chun
authors.initials: YC
authors.lastname: Yang
authors.forename: Jian-Gong
authors.initials: JG
authors.lastname: Shi
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000440:Butanols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D003512:Cyclohexanones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D045792:Norisoprenoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000461:Rhodophyta / Q000737:chemistry*
chemical_list: C528305:3-hydroxy-5,6-epoxy-7-megastigmene-9-one; C528304:3-hydroxyl-4,7-megastigmadien-9-one; D000970:Antineoplastic Agents; D000440:Butanols; D003512:Cyclohexanones; D045792:Norisoprenoids