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.