Antibacterial activity of the Iraqi Rheum ribes root

Abstract

The antibacterial activity of the ethanol, aqueous, and organic extracts from the root of Rheum ribes Linn (Polygonaceae) was examined. Four anthraquinone aglycone components, chrysopahnol, physcion, aloe emodin, and emodin, were isolated from the biologically active extract and identified by spectroscopic analysis. Emodin is recorded for the first time in this species. The MIC values of the biologically active extracts, aloe emodin, and emodin, were 500, 125, 250, and 63 μg/mL against Staphylococcus aureus, respectively. The extracts and compounds did not inhibit Pseudomonas aeruginosa and Escherichia coli at the highest concentration tested, 4000 and 250 μg/mL, respectively. © 2007 Informa Healthcare USA, Inc.