Two new 14, 15-secopregnane-type steroidal glycosides from the roots of <i>Cynanchum limprichtii</i>

<p>Two new steroidal glycosides <b>1</b> and <b>2</b>, along with three known ones (<b>3</b>–<b>5</b>), were isolated from the 95% ethanol extract of the roots of <i>Cynanchum limprichtii</i> Schltr. The structure of the new compounds was elucidated as 3-O-<i>α</i>-L-diginopyranosyl-(1→4)-<i>β</i>-D-digitoxopyranosyl-(1→4)-<i>β</i>-D-cymaropyranosyl-(1→4)-<i>β</i>-D-thevetopyranosyl-14, 16:15, 20:18, 20-triepoxy-14, 15-secopregn-4, 6, 8 (14)-triene (<b>1</b>) and 3-O-<i>α</i>-L-cymaropyranosyl-(1→4)-<i>β</i>-D-digitoxopyranosyl- (1→4)-<i>β</i>-D-3-demethyl-2-deoxythevetopyranosyl-14, 16: 15, 20: 8, 20-triepoxy-14, 15-secopregn-5, 8 (14)-diene (<b>2</b>) on the basis of spectroscopic analysis together with acidic hydrolysis. All compounds showed cytotoxic activity against the human cancer cell line HL60, with IC<sub>50</sub> values of 55.36, 65.41, 17.88, 17.68 and 33.5 μM, respectively. While, only compound <b>3</b> showed cytotoxicity against the Caco-2 cell line, with an IC<sub>50</sub> value of 67.47 μM.</p>