A novel xanthone dimer derivative with antibacterial activity isolated from the bark of Garcinia mangostana

Abstract

A novel xanthone dimer derivative, garmoxanthone (1), together with 10 known compounds (2–11), were isolated from bark of Garcinia mangostana. Their structures were established through spectroscopic methods. Garmoxanthone exhibited strong inhibitory activities against MRSA ATCC 43300 and MRSA CGMCC 1.12409 (with MIC values of both 3.9 μg/mL) and moderate activities against tested strains of Vibrio (with MIC values ranging from 15.6 to 31.2 μg/mL). Garmoxanthone is a unique xanthone dimer with linkage of a fused 5/6 ring system and its absolute configuration was elucidated on the basis of experimental and calculated electronic circular dichroism. Garmoxanthone exhibited strong antibacterial activity which partially validated the ethnobotanical use of G. mangostana in the treatment of infections.

Keywords:

• Garcinia mangostana
• xanthone dimer
• garmoxanthone
• antibacterial

Acknowledgement

We would like to thank all the members of Peng Cai’s group in Institute of Urban Environment, Chinese Academy of Sciences for their assistance in this work.