Triterpenic acids and flavonoids from Satureja parvifolia. Evaluation of their antiprotozoal activity

Bioassay-guided fractionation of a Satureja parvifolia MeOH extract led to the isolation of eriodictyol, luteolin and ursolic and oleanolic acids as its active components against Plasmodium falciparum K1. This is the first time these compounds are reported as constituents of S. parvifolia. Ursolic acid showed an IC50 of 4.9 mu g/ml, luteolin 6.4 mu g/ml, oleanolic acid 9.3 mu g/ml and eriodictyol 17.2 mu g/ml. Antiplasmodial activity of eriodictyol and luteolin is reported here for the first time. Besides, the four compounds showed activity against P falciparum 3137 strain and Trypanosoma brucei rhodesiense. Eriodictyol showed moderate activity on all the parasites but was the most selective compound as a result of its rather low cytotoxicity (IC50 174.2 mu g/ml) on the mammalian KB cell line.