title: [Study on antibacterial active components from Viola yedoensis].
abstract: OBJECTIVE
  Study on the antibacterial activity of Viola yedoensis and the antibacterial active compounds.
  
  
  METHODS
  The chemical compositions were isolated by means of solvent extraction, column chromatography on silica gel, sephadex LH-20 and crystallization. The antibacterial activities were tested by Neo-Sensitab disk-diffusion method, nephelometric analysis and plating method.
  
  
  RESULTS
  One new compound (4) along with three known compounds were isolated from this plant for the first time and were identified as aesculetin (1), 6,7-dimethoxycoumarin (2), scopoletin (3) and 5-methoxy-7-hydroxymethylcoumarin (4), respectively. All the compounds showed antibacterial and antibactericidal activities at varying degree on Streptococcus Aureas, S. agalactiae, S. uberis, S. dysgalactiae, E. coli and Salmonella, of which 1 was most active with 0.031- 0.313 g x L(-1) of minimal inhibitory concentrations (MIC) and 0.313 - 0.625 g x L(-1) of minimal bactericidal concentrations (MBC).
  
  
  CONCLUSIONS
  Viola yedoensis has a broad spectrum of antibacterial activity on animal pathogenic bacteria, and coumarins may be the main antibacterial activity ingredients.
authors.affiliation: Northwest A&F University, College of Life Science, Yangling 712100, China. sunyf.246@163.com
authors.forename: Yifang
authors.initials: Y
authors.lastname: Sun
authors.forename: Lili
authors.initials: L
authors.lastname: Du
authors.forename: Le
authors.initials: L
authors.lastname: Zhou
authors.forename: Wugang
authors.initials: W
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Miao
authors.forename: Xinjuan
authors.initials: X
authors.lastname: Yang
authors.forename: Huiling
authors.initials: H
authors.lastname: Geng
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D032413:Viola / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts