Bioactive compounds from Rhodiola rosea (Crassulaceae)

The methanol extract of the underground part of Rhodiola rosea was found to show inhibitory activity against Staphylococcus aureus. Bioactivity-guided fractionation of a 95% ethanol extract from the stems of R. rosea led to the isolation of five compounds: gossypetin-7-O-L-rhamnopyranoside (1), rhodioflavonoside (2), gallic acid (3), trans-p-hydroxycinnamic acid (4) and p-tyrosol (5). Their structures were elucidated by UV, IR, MS and NMR data, as well as by comparison with those of the literature. Compounds 1 and 2 were evaluated for their antibacterial and antiprostate cancer cell activities. Compounds 1 and 2 exhibited activity against Staphylococcus aureus with minimum inhibitory concentrations of 50 mu g/mL and 100 mu g/mL, respectively. Cytotoxicity studies of I and 2 also displayed activity against the prostate cancer cell line with IC50 values of 50 mu g/mL and 80 mu g/mL, respectively. Copyright (c) 2005 John Wiley & Sons, Ltd.