PROANTHOCYANIDINS FROM LOTUS-PEDUNCULATUS

A range of flavanols and proanthocyanidin dimers were isolated and ide ntified from Lotus pedunculatus. The more abundant polymeric proanthoc yanidins were also isolated and their chemical constitution studied by C-13 NMR and by acid-catalysed degradation in the presence of excess phloroglucinol. These results showed the polymers to be highly heterog eneous, with catechin, epicatechin, gallocatechin and epigallocatechin all being constituent components of both the extenders as well as the terminating units; Epigallocatechin was the most abundant extension u nit and catechin the more common terminating flavanoid. The average mo lecular size of the polymers was estimated by C-13 NMR to be ca eight flavanoid units and there was spectroscopic and chemical evidence to i ndicate that a small portion of these units were glycosylated. (C) 199 7 Elsevier Science Ltd. All rights reserved.