<p>A new triterpene saponin, catomentosaponin (<b>1</b>) and 11 known analogues (<b>2</b>–<b>12</b>) were isolated from the roots of <i>Catunaregam tomentosa</i>. The structures of <b>1</b>–<b>12</b> were determined on the basis of extensive NMR and MS data analysis. The sugar residues were identified by co-TLC and HPLC analysis after hydrolysis. All isolated compounds were evaluated for their cytotoxicity against KB and HeLa cell lines. Compound <b>2</b> showed moderate cytotoxicity against KB cell with IC<sub>50</sub> value of 24.84 μM.</p
