title: Purification and characterization of antibacterial substances produced by a marine bacterium Pseudoalteromonas haloplanktis strain.
abstract: OBJECTIVE
  To purify and characterize compounds with antimicrobial activity from Pseudoalteromonas haloplanktis inhibition (INH) strain.
  
  
  RESULTS
  The P. haloplanktis isolated from a scallop hatchery was used to analyse antibacterial activities. Crude extracts were obtained with ethyl acetate of the cultured broth, after separation of bacterial cells, and assays against six strains of marine bacteria and nine clinically important pathogenic bacteria. The active compounds were purified from ethyl acetate extracts, by a combination of SiO(2) column and thin layer chromatography. Two active fractions were isolated, and chemical structures of two products from the major one were unambiguously identified as isovaleric acid (3-methylbutanoic acid) and 2-methylbutyric acid (2-methylbutanoic acid), by comparing their mass spectra and (1)H- and (13)C-nuclear magnetic resonance spectra to those of authentic compounds.
  
  
  CONCLUSIONS
  In the antibacterial activity of P. haloplanktis INH strain, extra cell compounds are involucred, mainly isovaleric and 2-methylbutyric acids.
  
  
  CONCLUSIONS
  Production of antimicrobial compounds by marine micro-organisms has been widely reported; however, the efforts not always are conducted to purification and applications of these active compounds. This study is a significant contribution to the knowledge of compounds unique from marine bacteria as potential sources of new drugs in the pharmacological industry.
authors.affiliation: Departamento de Ciencias Químicas y Farmacéuticas, Universidad Católica del Norte, Antofagasta, Chile. ghayashi@ucn.cl
authors.forename: G
authors.initials: G
authors.lastname: Hayashida-Soiza
authors.forename: A
authors.initials: A
authors.lastname: Uchida
authors.forename: N
authors.initials: N
authors.lastname: Mori
authors.forename: Y
authors.initials: Y
authors.lastname: Kuwahara
authors.forename: Y
authors.initials: Y
authors.lastname: Ishida
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D002087:Butyrates / Q000302:isolation & purification* / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002855:Chromatography, Thin Layer / Q000379:methods; D045782:Hemiterpenes; D008826:Microbial Sensitivity Tests / Q000379:methods; D010421:Pentanoic Acids / Q000302:isolation & purification* / Q000494:pharmacology; D031161:Pseudoalteromonas / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D002087:Butyrates; D045782:Hemiterpenes; D010421:Pentanoic Acids; C008216:isovaleric acid; C019475:2-methylbutanoic acid