A new benzophenone glycoside from the leaves of Mitracarpus villosus

Abstract

A new benzophenone glycoside, mitraphenone A (1), together with three known compounds (2–4) were isolated from the leaves of the traditionally used medicinal plant Mitracarpus villosus (Rubiaceae) collected in Nigeria. A combination of one- and two-dimensional NMR spectroscopic and mass spectrometric measurements were carried out to identify the structure of 1. All isolated compounds (1–4) were screened for their antibacterial activity against several Gram-positive and Gram-negative bacteria. Compound 1 exhibited moderate activity against Enterococcus faecium (strains ATCC 35667 and ATCC 700221) and Staphylococcus aureus ATCC 25923 with MIC values ranging from 25 to 50 μM.

Keywords:

• Mitracarpus villosus
• benzophenone glycoside
• natural products
• antibacterial activity

Acknowledgements

The authors gratefully acknowledge TWAS-DFG for cooperative fellowship award that enabled this research. We are indebted to Prof. R. Kalscheuer (Heinrich Heine University, Duesseldorf, Germany) for antibacterial assays and to Prof. W. E. G. Müller (Johannes Gutenberg University, Mainz, Germany) for cytotoxicity assays.