Constituents from <i>Megacarpaea delavayi</i> Franch and their antimalarial activity

One new indole alkaloid, 1-methoxy-6-hydroxy-3-indoleformic acid (<b>1</b>), seven known analogous alkaloids (<b>2-8</b>), and fourteen known phenolic compounds (<b>9-22</b>) were isolated from the whole plant of <i>Megacarpaea delavayi</i> Franch. Their structures were determined using extensive spectroscopic methods. All compounds were firstly reported from genus <i>Megacarpaea. In vitro</i> antimalarial activity of the compounds towards <i>Plasmodium falciparum</i> 3D7 strain were evaluated. Indole alkaloids <b>1-7</b> showed weak antimalarial activity towards <i>P. falciparum</i> strain 3D7 at 50 µM, with inhibition rates ranging from 19.7 ± 0.9% to 25.8 ± 1.5%, no activity was observed at 5 µM.