Cardenolides from the bark of <i>Calotropis gigantea</i>

<div><p>Three new cardenolides (<b>1</b>–<b>3</b>) were isolated from the 90% ethanolic extract of the bark of a wild-type <i>Calotropis gigantea</i>. Their structures were determined by using NMR spectra and LC-MS analysis. Their inhibitory activities were evaluated against non-small cell lung carcinoma (A549) and human cervix epithelial adenocarcinoma (HeLa) cell lines. Compounds <b>1</b> and <b>3</b> exhibited strong inhibitory effect on two cancer cell lines.</p></div