Chemical Constituents, Antimicrobial and Cytotoxic Activities of Hypericum riparium (Guttiferae)

Betulinic acid (1), 5-hydroxy-3-methoxyxanthone (2), 1,6-dihydroxy-7-methoxyxanthone (3), daucosterol (4), bijaponicaxanthone C (5), hypercalin C (6), 1-hydroxy-6,7-dimethoxyxanthone (7), cadensin D (8) and 5-hydroxy-1,3-dimethoxyxanthone (9) were isolated from the roots of Hypericum riparium. These compounds are reported for the first time from this plant. The extracts and two of the isolated compounds (2 and 8) exhibited both antibacterial and antifungal activities that varied between the microbial species (MIC = 0.97-250 µg/mL). In addition, the brine-shrimp (Artemia salina) lethality bioassay of compound 6 showed potent cytotoxicity with LD 50 of 3.23 µg/mL.