title: [3-O-β-chacotriosyl benzyl ursolate inhibits entry of H5N1 influenza virus into target cells].
abstract: OBJECTIVE
  To study the inhibitory activities of 3-O-β-chacotriosyl benzyl ursolate and its derivatives as potential new anti-influenza virus agents against the entry of H5N1 influenza viruses into the target cells.
  
  
  METHODS
  Four target compounds were designed and synthesized, which were structurally related to the lead compound 3-O-β-chacotriosyl methyl ursolate (1). The inhibitory activities of these compounds were tested at a cellular level psuedovirus system targeting H5N1 influenza viruse entry.
  
  
  CONCLUSIONS
  The compounds 1b, 1c and 1d showed potent inhibitory activities against the entry of A/Thailand/Kan353/2004 pseudovirus into the target cells, and among them compound 1d showed the strongest inhibitory activity with an IC50 value of 0.96 ± 0.10 µmol/L. The structure-activity relationship analysis of these compounds indicated that when 17-COOH of ursolic acid was esterified, introduction of Me groups rather than aryl groups more strongly enhanced the inhibitory activity. Changing 17-COOH of ursolic acid into amide could increase the antiviral activity and decrease the cytotoxicity of the compounds in MDCK cells.
authors.affiliation: College of Resources and Environment, South China Agricultural University, Guangzhou 510642, China. E-mail: vinsin1021@126.com.
authors.forename: Gaopeng
authors.initials: G
authors.lastname: Song
authors.forename: Xintian
authors.initials: X
authors.lastname: Shen
authors.forename: Yibin
authors.initials: Y
authors.lastname: Li
authors.forename: Yushan
authors.initials: Y
authors.lastname: Zheng
authors.forename: Ping
authors.initials: P
authors.lastname: Xiong
authors.forename: Shuwen
authors.initials: S
authors.lastname: Liu
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry*; D004285:Dogs; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects* / Q000502:physiology; D061985:Madin Darby Canine Kidney Cells; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000737:chemistry*; D053586:Virus Internalization / Q000187:drug effects*; D000097245:Ursolic Acid
chemical_list: D000998:Antiviral Agents; D014315:Triterpenes; D000097245:Ursolic Acid