Structural determination of two new acacic acid-type saponins from the stem barks of <i>Albizia zygia</i> (DC.) J. F. Macbr

<p>As a continuation of our interest in the study of triterpenoid saponins from <i>Albizia zygia</i>, phytochemical investigation of its stem barks led to the isolation of two new oleanane-type saponins, named zygiaosides <b>C</b>–<b>D</b> (<b>1</b>–<b>2</b>). Their structures were established on the basis of extensive analysis of 1D and 2D NMR (1H-, 13C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as, 3-<i>O</i>-[ <i>β</i>-d-glucopyranosyl-(1→2)-[<i>α</i>-l-arabinopyranosyl-(1→6)]-<i>β</i>-d-glucopyranosyl]-21-<i>O</i>-[(2<i>E</i>,6<i>S</i>)-2,6-dimethyl-6-<i>O</i>-(<i>β</i>-d-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-<i>O</i>-<i>α</i>-l-arabinofuranosyl-(1→4)-[<i>β</i>-d-glucopyranosyl-(1→3)]-<i>α</i>-l-rhamnopyranosyl-(1→2)-<i>β</i>-d-glucopyranosyl ester <b>(1</b>) and 3- <i>O</i>-[<i>β</i>-d-glucopyranosyl-(1→2) -[ <i>β</i>-d-fucopyranosyl-(1→6)]-<i>β</i>-d-glucopyranosyl]-21-<i>O</i>-[(2<i>E</i>,6<i>S</i>)-2,6-dimethyl-6-<i>O</i>-(<i>β</i>-D-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-<i>O</i>-<i>α</i>-l-arabinofuranosyl-(1→4)-[<i>β</i>-d-glucopyranosyl-(1→3)]-<i>α</i>-l-rhamnopyranosyl-(1→2)-<i>β</i>-d-glucopyranosyl ester <b>(2</b>).</p>