Xanthone with Antibacterial Activity against Methicillin-resistant Staphylococcus aureusfrom Hypericum ascyron L

Objective: Antibiotic-resistant bacteria have been emerging worldwide as one of the most important problems in dental and medical fields, especially acute oral infection. Therefore, new agents are needed to treat the methicillin-resistant Staphylococcus aureus (MRSA) from acute infection. To investigate the antibacterial agents against MRSA from acute oral infection, several natural product extracts were screened. The methanol extract of Hypericum ascyron (H. ascyron) was found to have inhibitory activity against MRSA. Method: H. ascyron was extracted with MeOH. The extract was suspended in H₂O and partitioned with CHCl₃, EtOAC, and n-BuOH in sequence. The CHCl₃ fraction showed remarkable antibacterial activity against MRSA. The antibacterial activity compound against MRSA by MIC was isolated successively through the screening system and various chromatography methods. Result: From this active chloroform subfraction, isolation and identification finally gave 1,3,6,7-tetrahydroxy-8-(3-methylbut-2-enyl)-xanthone by spectroscopic methods (MS, ¹H-NMR and ¹³C-NMR) as an active principle. The compound showed significant growth inhibitory effect against MRSA. Conclusions: These results suggest that 1,3,6,7-tetrahydroxy-8-(3-methylbut-2-enyl)-xanthone might have the antibacterial activity against MRSA from acute oral infection. Supported by a grant of No. R01-2001-00133-0 from KOREF