The NMR studies on two new furostanol saponins from Agave sisalana leaves

The detailed NMR studies and full assignments of the 1 H and 13 C spectral data for two new furostanol saponins isolated from Agave sisalana leaves are described. Their structures were established using a combination of 1D and 2D NMR techniques including 1 H, 13 C, 1 H 1 H COSY, TOCSY, HSQC, HMBC and HSQC‐TOCSY, and also FAB‐MS spectrometry and chemical methods. The structures were established as (25 S )‐26‐(β‐ D ‐glucopyranosyl)‐22 ξ‐hydroxyfurost‐12‐one‐3β‐yl‐ O ‐α‐ L ‐rhamnopyranosyl‐(1→4)‐β‐ D ‐glucopyranosyl‐(1→3)‐ O ‐[ O ‐β‐ D ‐glucopyranosyl‐(1→2)]‐ O ‐β‐ D ‐glucopyranosyl‐(1→4)‐β‐ D ‐galacto‐ pyranoside (1) and (25 S )‐26‐(β‐ D ‐glucopyranosyl)‐22ξ‐hydroxyfurost‐5‐en‐12‐one‐3β‐yl‐ O ‐α‐ L ‐rhamno‐ pyranosyl‐(1→4)‐β‐ D ‐glucopyranosyl‐(1→3)‐ O ‐[ O ‐β‐ D ‐glucopyranosyl‐(1→2)]‐ O ‐β‐ D ‐glucopyranosyl‐ (1→4)‐β‐ D ‐galactopyranoside (2). Copyright © 2006 John Wiley & Sons, Ltd.