Continentalic acid (CA, (-)-pimara-8(14), 15-diene-19-oic acid) was isolated from the roots of Aralia cordata (Araliaceae) using bioassay-guided fractionation of a crude chloroform extract. The antibacterial activity of CA against Enterococcus faecalis and Enterococcus gallinarium was estimated by determining minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). CA exhibited potent activity against standard vancomycin-resistant enterococci (VRE) and vancomycin-susceptible enterococci (VSE), with MICs and MBCs values between 4 and 8μg/mL and 4 and 16μg/mL, respectively. This compound exhibited potent activity against strains of VRE, which are highly resistant to clinically useful antibiotics. These findings suggest that continentalic acid may be useful in controlling enterococcal infection.

• Kang-Ju Kim(Department of Oral Microbiology, School of Dentistry and Biomaterial Implant Research Institute) Corresponding author
• Seung-Il Jeong(Department of Oral Microbiology, School of Dentistry and Biomaterial Implant Research Institute, Jeonju Biomaterials Institute)
• Yeon-Hee Yun(Department of Oral Microbiology, School of Dentistry and Biomaterial Implant Research Institute)
• Shin-Moo Kim(Department of Clinical Pathology, Wonkwang Health Science College)
• Kui-Hyun Yoon(Department of Laboratory Medicine, Wonkwang Univ. Sanbon Hospital)