Antibacterial Activity of Extracts Prepared from Tropical and Subtropical Plants on Methicillin-Resistant Staphylococcus aureus.

The antibacterial activity of the extracts prepared from 181 species (75 families) of tropical and subtropical plants was screened against various types of pathogenic bacteria. Among the 505 extracts tested, 53 of them inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA). The active extracts obtained from barks of Shorea hemsleyana and roots of Cyphostemma bainessi were separated to their components, some of which greatly reduced the viable cell number of MRSA. These active compounds were all identified as stilbene derivatives. Hemsleyanol d, one of the stilbene tetramer isolated from S. hemsleyana, was the most effective compound and had MIC of 2 μg/ml.