title: [Sulfated modification conditions optimization of astragalus polysaccharide by orthogonal test and anti-IBDV activity determination of the modifiers].
abstract: OBJECTIVE
  To optimize the sulfated modification conditions of astragalus polysaccharide (APS) and probe into the probability of sulfated modification to enhance APS activity.
  
  
  METHODS
  Total APS extracted by one-step ethanol precipitation and three fractional APSs extracted by stepwise ethanol precipitation method and purified were modified by chlorosulfonic acid-pyridine method. The modification conditions were optimized by L9 (3(4)) orthogonal design taking the ratio of chlorosulfonic acid to pyridine, reaction temperature and time. The degree of substitution (DS) was tested by sulfate barium turbidimetric method. The anti-IBDV activity of modification production was tested by MTT method.
  
  
  RESULTS
  The optimized modification conditions were 1 : 6 of chlorosulfonic acid to pyridine, reaction temperature of 95 degrees C and reaction time of 1 hour.
  
  
  CONCLUSIONS
  Sulfated modification can enhance the antiviral activity of APS, which related to DS.
authors.affiliation: Institute of Traditional Chinese Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Huang
authors.forename: Yuan-Liang
authors.initials: YL
authors.lastname: Hu
authors.forename: Yu
authors.initials: Y
authors.lastname: Lu
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.forename: Zhen-Huan
authors.initials: ZH
authors.lastname: Guo
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry* / Q000494:pharmacology; D027883:Astragalus Plant / Q000737:chemistry*; D002645:Chickens; D005240:Feasibility Studies; D007243:Infectious bursal disease virus / Q000187:drug effects; D011134:Polysaccharides / Q000737:chemistry* / Q000494:pharmacology; D013463:Sulfuric Acid Esters / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D013997:Time Factors
chemical_list: D000998:Antiviral Agents; D011134:Polysaccharides; D013463:Sulfuric Acid Esters