Constituents of Aegle marmelos from Myanmar.

Five compounds ( 1 - 5 ), including three coumarins ( 1 - 3 ) and two alkaloids ( 4 , 5 ) were isolated during the first investigation of the stem bark of Aegle marmelos (L.) Corrêa. collected in Myanmar. Their structures were determined by NMR spectra analysis. Among them, 7´- O -ethylmarmin ( 1 ) and 2- O -ethyltembamide ( 5 ) were identified as new compounds. Skimmianine ( 4 ) showed moderate cytotoxicity against a HeLa cell line, and 7´- O -ethylmarmin ( 1 ), marmin ( 2 ), and (+)-epoxyaurapten ( 3 ) displayed weak radical scavenging activity according to a DPPH scavenging assay.