Structure elucidation and NMR spectral assignments of one new dammarane-type triterpenoid saponin from black ginseng

New dammarane-type triterpenoid saponin, named 22(<i>R</i>)-notoginsenoside Ab1 (<b>1</b>), together with thirteen known dammarane-type triterpenoid saponins (<b>2</b>-<b>14</b>) was isolated from the EtOH extract of black ginseng and their structures were elucidated on the basis of one- and two-dimensional NMR (including ¹H-NMR, ¹³C-NMR, HSQC, HMBC, ROESY) and calculated ECD. Among them, compounds <b>1-2</b> and <b>6</b>-<b>8</b> were isolated for the first time from ginseng and black ginseng. Besides, the absolute structure of 22(<i>R</i>)- and 22(<i>S</i>)- notoginsenoside Ab1 were distinguished by ECD for the first time.