title: Investigation of the antibacterial activity of 3-O-octanoyl-(-)-epicatechin.
abstract: OBJECTIVE
  To measure antibacterial activity of the semi-synthetic flavonoid 3-O-octanoyl-(-)-epicatechin and investigate the mechanism of action.
  
  
  RESULTS
  MICs determined by the broth microdilution method were 50 microg ml(-1) for beta-lactam sensitive and resistant Staphylococcus aureus, and 100 microg ml(-1) for vancomycin sensitive and resistant enterococci. In time-kill studies, 100 microg ml(-1) 3-O-octanoyl-(-)-epicatechin reduced colony forming unit numbers of antibiotic sensitive and methicillin-resistant Staph. aureus below detectable levels within 120 min. Bacterial aggregation was not observed when cells exposed to 3-O-octanoyl-(-)-epicatechin were examined by light microscopy. It was also shown that 50 microg ml(-1) 3-O-octanoyl-(-)-epicatechin is capable of reducing colony forming unit numbers of high cell density Staph. aureus populations by 80-fold within 60 min incubation, and inducing leakage of 50% of their internal potassium within just 10 min.
  
  
  CONCLUSIONS
  3-O-Octanoyl-(-)-epicatechin is active against Gram-positive bacteria, has bactericidal activity against both antibiotic sensitive and resistant strains, and is likely to exert its primary antibacterial effect by damaging the cytoplasmic membrane.
  
  
  CONCLUSIONS
  3-O-Octanoyl-(-)-epicatechin has significant antibacterial activity and additional structural modification and/or formulation studies may allow this to be potentiated.
authors.affiliation: School of Pharmacy, The Robert Gordon University, Schoolhill, Aberdeen, UK.
authors.forename: T P T
authors.initials: TP
authors.lastname: Cushnie
authors.forename: P W
authors.initials: PW
authors.lastname: Taylor
authors.forename: Y
authors.initials: Y
authors.lastname: Nagaoka
authors.forename: S
authors.initials: S
authors.lastname: Uesato
authors.forename: Y
authors.initials: Y
authors.lastname: Hara
authors.forename: A J
authors.initials: AJ
authors.lastname: Lamb
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002449:Cell Aggregation / Q000187:drug effects; D024881:Drug Resistance, Bacterial / Q000502:physiology; D016983:Enterococcus / Q000166:cytology / Q000187:drug effects*; D005419:Flavonoids / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000166:cytology / Q000187:drug effects*
chemical_list: C499927:3-O-octanoyl-catechin; D000900:Anti-Bacterial Agents; D005419:Flavonoids; D002392:Catechin