Steroidal saponins from the leaves of Agave macroacantha

A new monodesmosidic spirostanol saponin, along with three known saponins was isolated from Agave macroacantha Zucc leaves. The structure of the new saponin was established as hecogenin-3-O-alpha-L-rhamnopyranosyl (1 -> 4) [beta-D-xylopyransoyl (1 -> 3)[beta-D-glucopyranosyl (1 -> 2)] beta-D-glucopyranosyl (1 -> 4) beta-D-galactopyranoside. The (1)Hand (13)C resonances of the four compounds were assigned using a combination of 1D and 2D NMR techniques including (1)H, (13)C, COSY, TOCSY, ROESY, HSQC and HMBC NMR and confirmed by mass spectrometry. (C) 2009 Elsevier B.V. All rights reserved.