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

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  μ g ml^?1 towards MRSA and a value of 2 to 4  μ g 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.