Application of MS and NMR to the structure elucidation of complex sugar moieties of natural products: exemplified by the steroidal saponin from Yuccafilamentosa L.

An approach, using well characterized procedures, is presented that should be of general applicability for the structural elucidation of complex sugar moieties of natural products. The methods used are exemplified by the stru cture elucidation of a new gitogenin-based steroidal saponin that has a str ong leishmanicidal activity similar to preparations used in clinical practi ce and has been isolated by bioactivity-guided fractionation of the ethanol ic extract of Yucca filamentosa L. leaves. The saponin has been characteriz ed as 3-O-((beta -D-glucopyranosyl-(1 --> 3)- beta -D-glucopyranosy-( 1 --> 2))(alpha -L-rhamnopyranosyl-( 1 --> 4)-beta -D-glucupyranosyl-( 1 --> 3)) -beta -glucopyranosyl-(l D-glucopyranosyl-(1 --> 4)-beta -D-galactopyranosy l)-25R.5 alpha -spirostan-2 alpha .3 beta -diol. (C) 2001 Published by Else vier Science Ltd. All rights reserved.