Growth-inhibitory Components in the Juice of Aronia melanocarpa with Activity against Staphylococcus aureus

Summary : Staphylococcus aureus is a resident bacterium in healthy humans. However, methicillin-resistant S. aureus (MRSA) is a major causative bacterium of nosocomial infectious diseases. In addition, the enterotoxin produced by S. aureus causes food poisoning. In this study, we searched for components within the juice of aronia ( Aronia melanocarpa ) that would exert antibacterial activity against the growth of S. aureus . To search these active components, we carried out different extraction methods. We found that the water-soluble components of freeze-dried aronia juice had a strong antimicrobial effect against S. aureus strains. To search for the active in-gredients, we carried out fractionation of aronia juice by reverse-phase chromatography and examined the antibacterial effects of fractions eluted with 20-30 % acetonitrile. Mass spectrometry identified some low-molecular-weight compounds ― chlorogenic acid, protocatechuic acid, and gentisic acid ― as components of aronia.