Bioactivity guided isolation of antimicrobial compounds from Lythrum salicaria

Lythrum salicaria extracts showed activity against the phytopathogenic fungus Cladosporium cucumerinum and activity against the bacteria Staphylococcus aureus, Proteus mirabilis and Microccocus luteus. Bioautography on thin-layer chromatograms was used to isolate the two antifungal triterpenoids oleanolic and ursolic acid. The hexahydroxydiphenoyl ester vescalagin was isolated as active principle of the antibacterial activity. Furthermore, the flavon-C-glucosides vitexin, isovitexin, orientin and isoorientin were isolated.