<p>Using various chromatographic separations, sixteen compounds, including one new triterpene saponin named aegicoroside A (<b>1</b>), were isolated from the leaves of the Vietnamese mangrove <i>Aegiceras corniculatum</i>. Their structures were determined by spectroscopic methods such as 1D and 2D NMR and HR-ESI-MS. The cytotoxic activities of the isolated compounds against MCF7 (breast), HCT116 (colon), B16F10 (melanoma), and A549 (adenocarcinoma) cancer cell lines were also evaluated. Strong cytotoxicity was observed for sakurasosaponin (<b>2</b>) against all four cancer cell lines and for sakurasosaponin methyl ester (<b>3</b>) against MCF7, A549, and HCT116 cell lines with IC<sub>50</sub> values ranging from 2.89 ± 0.02 to 9.86 ± 0.21 μM.</p
