title: [2-Pyridinethiolate derivatives from branches and leaves of Polyalthia nemoralis and their cytotoxic activities].
abstract: OBJECTIVE
  To investigate the active constituents of the branches and leaves of Polyalthia nemoralis.
  
  
  METHODS
  The compounds were isolated and purified by silica gel, macroporous adsorption resin and Sephadex LH-20 column chromatographic methods. Their chemical structures were elucidated on the basis of physicochemical properties and spectral data.
  
  
  RESULTS
  Eight compounds were isolated and identified as: zincpolyanemin (1), nickel bis-(pyridine-N-oxide-2-thiolate) (2), cupric bis (pyridine-N-oxide-2-thiolate (3), 2-methanesulfonyl-pyridine (4), 2-pyridinethiolate N-oxide (5), 2,2'-dithiodipyridine (6), 2-thiohydroxypyridin-N-oxide-2-S-beta-D-gluco pyranoside (7) and pyridine-N-oxide (8), respectively.
  
  
  CONCLUSIONS
  Compounds 2, 4-6, 8 were new natural products. The bioassays in vitro against five human tumor cell lines with MTT method showed stronger cytotoxic activities (IC50 0.05-0.09 mg x L(-1)) for compounds 1-3 and 6, and weaker cytotoxic activities (IC50 5.49-7.71 mg x L(-1)) for compound 5.
authors.affiliation: Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine (Ministry of Education), Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Ziming
authors.initials: Z
authors.lastname: Lu
authors.forename: Shengjun
authors.initials: S
authors.lastname: Dai
authors.forename: Ruoyun
authors.initials: R
authors.lastname: Chen
authors.forename: Dequan
authors.initials: D
authors.lastname: Yu
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D018515:Plant Leaves / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry*; D031044:Polyalthia / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*
chemical_list: D004365:Drugs, Chinese Herbal; D011725:Pyridines; C023666:pyridine