title: [Active neuraminidase constituents of Polygonum cuspidatum against influenza A(H1N1) influenza virus].
abstract: OBJECTIVE
  To isolate and identify active neuraminidase constituents of Polygonum cuspidatum against influenza A (H1N1) influenza virus.
  
  
  METHODS
  On the basis of the bioassay-guided fractionation,such chromatographic methods as silica gel, sephadex LH-20 and HPLC were adopted to isolate active constituents of extracts from Polygonum cuspidatum, and their molecular structures were identifiied on the basis of their spectral data such as NMR and MS and physico-chemical properties.
  
  
  RESULTS
  Seven compounds were isolated from the ethyl acetate extract of P. cuspidatum and identified as 2-methoxystypandrone (1), emodin (2), resveratrol (3), polydatin (4), emodin-8-O-beta-D-glucopyranoside (5), (E)-3, 5, 12-trihydroxystilbene-3-O-beta-D-glucopyranoside-2'-(3", 4", 5"-trihydroxybenzoate) (6) and catechin-3-O-gallate (7), respectively. Among them, the NA test showed that compounds 3, 6 and 7 had inhibitory effect against NAs activity, with IC50 values of 129.8, 44.8 and 21.3 micromol x L(-1), respectively. Moreover, the further CPE test showed compounds 6 and 7 had significant inhibitory effect against H1N influenza virus (EC50 = 5.9, 0.9 micromol x L(-1), respectively), with very low cytotoxicity to the host cells, their therapeutic selective index(SI) in MDCK cells ranged from 56 to 269.
  
  
  CONCLUSIONS
  The neuraminidase inhibitors against H1N1 anti-influenza virus isolated from extracts of P. cuspidatum on the basis of the bioassay-guided fractionation are significant in specifying their therapeutic material basis and drug R&D against influenza.
authors: Key Laboratory of Chinese Medicinal Resource from Lingnan, Ministry of Education, Research Center of Medicinal Plant Resource Science and Engineering, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
authors: Kao-Tan
authors: KT
authors: Chen
authors: Wei-Ling
authors: WL
authors: Zhou
authors: Jia-Wei
authors: JW
authors: Liu
authors: Mian
authors: M
authors: Zu
authors: Zi-Ning
authors: ZN
authors: He
authors: Guan-Hua
authors: GH
authors: Du
authors: Wei-Wen
authors: WW
authors: Chen
authors: Ai-Lin
authors: AL
authors: Liu
mesh_terms: D002460:Cell Line; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D045468:Fallopia japonica / Q000737:chemistry*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects* / Q000201:enzymology; D007251:Influenza, Human / Q000821:virology; D015394:Molecular Structure; D009439:Neuraminidase / Q000037:antagonists & inhibitors*
chemical_list: D004365:Drugs, Chinese Herbal; D004791:Enzyme Inhibitors; D009439:Neuraminidase