The antimicrobial activity of heyneanol A extracted from the root of Taiwanese wild grape.

ABSTRACT

AIMS: To search for antimicrobial compounds against pathogenic bacteria from grape vines (Vitis spp.). To investigate the antimicrobial efficacy of active compounds towards methicillin-resistant Staphylococcus aureus (MRSA). METHODS AND RESULTS: The root extracts of taiwanese wild grape (Vitis thunbergii var. taiwaniana) showed marked activities against Gram-positive bacteria using the disc diffusion method. After purification, the active compound 1 was confirmed as heyneanol A by mass spectroscopy and nuclear magnetic resonance. Heyneanol A showed an minimum inhibitory concentration (MIC) value of 2 microg ml(-1) towards MRSA and a value of 2 to 4 microg ml(-1) for Enterococcus faecium, S. aureus, Streptococcus agalactiae and Streptococcus pyogenes. In addition, the contents of heyneanol A were determined as 36 mg g(-1) in roots of taiwanese wild grape. CONCLUSIONS: The root extracts of grapevines have good antimicrobial activities towards some strains of Gram-positive pathogens. Heyneanol A, the major antimicrobial compound, is especially active towards MRSA. In addition, the abundances of heyneanol A and other stilbenes in the roots of grapevines make it possible to produce natural antimicrobial compounds from this plant species. SIGNIFICANCE AND IMPACT OF THE STUDY This study reports for the first time the antimicrobial compounds in the root extracts of grapevines. The results will have clinical significance owing to their activities against MRSA.