A new lactam alkaloid from <i>Portulaca oleracea</i> L. and its cytotoxity

<p>A new lactam alkaloid named oleraciamide D (<b>1</b>), indentified as (5<i>R</i>)-4-(3-methoxy-4-hydroxyphenyl)-5-(4-hydroxyphenyl)-5,6-dihydropyridin-2(1<i>H</i>)-one, together with five known compounds, indole-3-aldehyde (<b>2</b>), portulacatone (<b>3</b>), <i>N</i>-<i>trans</i>-feruloyloctopamine (<b>4</b>), <i>N</i>-<i>trans</i>-feruloyl-3′-O-methyldopamine (<b>5</b>) and <i>N</i>-<i>trans</i>-feruloyltyramine (<b>6</b>) were isolated from <i>Potulaca oleracea</i> L. Among them, indole-3-aldehyde (<b>2</b>) was isolated from the medicine for the first time. The structure of the new alkaloid was elucidated via UHPLC-ESI-Q-TOF/MS, 1D NMR and 2D NMR. The five known compounds were established by comparing the <sup>1</sup>H-NMR and <sup>13</sup>C NMR with the reported literature. Oleraciamide D (<b>1</b>) showed cytotoxicity against SH-SY5Y cells when concentration at 50 uM by CCK-8 method.</p>