ENANTIOSELECTIVE INTERACTION OF QUIZALOFOP-ETHYL WITH BOVINE SERUM ALBUMIN DEMOSTRATED BY FLUORESCENCE QUENCHING

摘要

Pesticides are of environmental significance because they have been widely used and have potential ecotoxicity. Plasma proteins binding can be an effective mean of affecting the toxicological properties of xenobiotics moleculars. In this study, we investigated the interaction of RS-Quizalofop-ethyl (RS-QZL)and R-Quizalofop-ethyl (R-QZL) with bovine serum albumin (BSA) using tryptophan fluorescence quenching. In the discussion of the mechanism, it was proved that the fluorescence quenching of BSA by RS- and R-QZL is a result of the formation of a QZL-BSA complex. Quenching constants were determined using the Sterns-Volmer equation to provide a measure of the binding affinity between RS-, R-QZL and BSA. The thermodynamic parameters △G, △H, and △S at different temperatures were calculated. And suggested that the van der Waals interactions play a major role in both RS- and R-QZL-BSA association.