Acid-base properties of selected flavonoid glycosides

Naringin dissociation constants were determined by analytical methods. Dissociation reactions of naringin and rutin were modelled with AM1 quantum chemistry method. The analysis of physicochemical parameters achieved by AM1 method allowed for determination of acid-base properties of hydroxyl group of flavonoid glycosides studied. The sequence in which hydrogen atoms dissociate from hydroxyl groups in flavonoid glycosides is 7-OH > 4'-OH > 3'-OH > 5-OH. The analysis of selection of descriptors essential for further studies aiming at elucidation of relationship between acidity of hydroxyl groups and their biological effect was per-formed. (c) 2005 Elsevier B.V. All rights reserved.