Antihyperglycemic activity of phenylpropanoyl esters of catechol glycoside and its dimers from Dodecadenia grandiflora

Bioactivity-guided separation of an anti hyperglycemic extract from the leaves of Dodecadenia grandiflora afforded two phenylpropanoyl esters of catechol glycosides (1 and 4) and two lignane bis(catecol glycoside)esters (2 and 3). Their structures were established on the basis of extensive spectroscopic analysis (1D and 2D-NMR, MS). Compounds 2 and 3 are believed to be derived from dimerization via the two phenylpropanoid units of 1. Compounds 1-4 showed significant antihyperglycemic activity in streptozotocin-induced (STZ) diabetic rats, which is comparable to the standard drug metformin. Our results provide support to explain the use of D. grandiflora as antihyperglycemic agent by the traditional medical practitioners. (C) 2009 Elsevier Ltd. All rights reserved.