The activity-guided fractionation of the extract of the herb of Prunella vulgaris (Labiatae) led to the isolation of four triterpenes, i.e., betulinic acid, ursolic acid, 2 alpha,3 alpha-dihydroxyurs-12-en-28-oic acid, and 2 alpha-hydroxyursolic acid. One of these compounds, 2 alpha,3