Cycloartanes from leaves of Combretum quadrangulare growing in Vietnam

Two new cycloartanes, combretic acid C (1) and combretanone I (3), were isolated from the leaves of Combretum quadrangulare Kurz, together with the previously-reported combretic acids A-B (2 and 5) and combretanone A (4). An extensive set of spectroscopic methods were used to elucidate the structures of these compounds. Cytotoxicity against the K562 cancer cell line was evaluated. Compound 1 showed strong activity, with an IC50 value of 9.7 mu M. The other compounds showed moderate activity. Alpha-glucosidase inhibition was also evaluated. The isolated compounds showed moderate inhibition, with IC50 values in the range 102.2-194.7 mu M.

Automated summary

Two new compounds with anticancer and alpha-glucosidase inhibitory activities were isolated from the leaves of Combretum quadrangulare Kurz.