Bergenin (1), major bioactive compound isolated from methanolic extract of Mallotus philippinensis, displayed moderate AGE inhibition activity (IC50 = 186.73 mu M). A series of derivatives of bergenin (3a-k) containing variety of aromatic acids were synthesized under mild conditions by modification of sugar part. Selective esterification of hydroxyl groups on the sugar part enhanced antiglycation potential of bergenin. Compounds 3j and 3k exhibited potent antiglycation activity with the IC50 values of 60.75 and 12.28 mu M, respectively. (C) 2011 Elsevier Ltd. All rights reserved.
Structure-activity relationships of bergenin derivatives effect on α-glucosidase inhibition
The alpha-glucosidase inhibitory activities of bergenin derivatives were evaluated. Bergenin derivatives were synthesized from bergenin which is a characteristic compound of B. ligulata. A new bergenin derivative, 11-O-(3',4'-dimethoxybenzoyl)-bergenin showed the highest potent inhibitory activity among those of bergenin derivatives. The presence of substituents at 3',4'-position in bergenin derivatives altered the alpha-glucosidase inhibitory activity. 11-O-(3', 4'-dimethoxybenzoyl)-bergenin was noncompetitive inhibitor for alpha-glucosidase. The present study reveals that bergenin derivatives could be classified as a new group of alpha-glucosidase inhibitors.