title: [Polyketone Reaction in Biosynthetic Pathways of 2, 3, 5, 4'-Tetrahydroxy Stilhene-2-O-β-D-glucoside in Polygonum multiflorum by Biocatalysis].
abstract: OBJECTIVE
  2, 3, 5, 4'-Tetrahydroxy stilbene-2-O-β-D-glucoside (THSG), the active ingredient of Polygonum multiflorum, its polyketone reaction in the biosynthesis pathways was studied by biocatalysis method.
  
  
  METHODS
  The substrates 4-coumaroyl-CoA and malonyl-CoA were catalyzed in vitro by the crude enzyme extracted from Polygonum multiflorum callus, then the products were verified by HPLC and LC-MS methods. And the crude enzyme was analyzed by ammonium sulfate precipitation method and SDS-PAGE.
  
  
  RESULTS
  HPLC chromatogram showed the same retention time of both the product and resveratrol standards; LC-MS spectra showed that the m/z of product was 227, which was consistent with resveratrol standards under the mode of negative ion; Ammonium sulfate (AS) precipitation method showed AS of 40% - 70% had catalytic activity,and 50% - 60% was the optimum; SDS-PAGE showed protein bands were obviously different among different AS concentration between 20% - 80%, the protein band of 42 kDa was found in AS of 50% - 60%, which had the same molecular weight with stilbene synthase.
  
  
  CONCLUSIONS
  The product of polyketone reaction in the biosynthesis of THSG is resveratrol rather than THSG, so it is speculated that THSG is the conversion product of resveratrol instead of the direct product of the polyketone reaction.
authors.forename: Lei
authors.initials: L
authors.lastname: Lei
authors.forename: Wan-xia
authors.initials: WX
authors.lastname: Xia
authors.forename: Li
authors.initials: L
authors.lastname: Shao
authors.forename: Shu-jin
authors.initials: SJ
authors.lastname: Zhao
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D055162:Biocatalysis; D053898:Biosynthetic Pathways; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D000068676:Fallopia multiflora / Q000737:chemistry*; D005960:Glucosides / Q000096:biosynthesis*; D013058:Mass Spectrometry; D000077185:Resveratrol; D013267:Stilbenes / Q000032:analysis
chemical_list: C489707:2',3',4',5'-tetrahydroxystilbene-2-O-beta-D-glucoside; D005960:Glucosides; D013267:Stilbenes; D000217:Acyltransferases; C055200:resveratrol synthase; C022674:stilbene synthase; D000077185:Resveratrol