Cycloartane-type triterpene glycosides from Beesia calthaefolia and their anticomplement activity.

Two new 9,19-cycloartane triterpenes (1, 2), together with three known compounds (3-5), were isolated from the whole plant of Beesia calthaefolia. Their structures were determined by the application of spectroscopic analyses and chemical methods. Compound 1 showed moderate anticomplement activity similar to that of the positive control (rosmarinic acid), while compounds 3 and 4 showed weak activity. The results suggest that 6'-O-(4″-hydroxy-3″-methoxy-benzoyl)-β-D-glucosyl of 9,19-cycloartane-type triterpenoids could be a structure that is essential for anticomplement activity.