Two New Xanthones From Swertia atroviolacea and Their Anti-5 α -Reductase Activity

Two new xanthones, atroxanthones A and B ( 1 and 2 ), together with four known xanthones ( 3–6 ), were isolated from the whole herb of Swertia atroviolacea. The structures of the metabolites were established on the basis of detailed spectroscopic analysis. Compounds 1 and 2 were evaluated for their anti-5α-reductase activity. The results revealed that 1 and 2 had weak activity with reductase inhibitions of 52.3 ± 2.5% and 42.9 ± 2.8%, respectively.