Investigation on Effect of Fluorescence Enhancement of Danshensu-BSA System by Synchronous Fluorescence Spectrometry

KeyWord:synchronous fluorescence spectrum  Danshensu  BSA  fluorescence enhancement

Abstract:

      Danshensu is one of the water soluble salvianolic acids which is extracted from Salvia. In this article, the interaction between Danshensu and bovine serum albumin (BSA£© in aqueous solution was investigated by ultraviolet spectra and synchronous fluorescence spectra. Ultraviolet spectra showed that Danshensu could interact with BSA to form a stable complex. Fluorescence spectra showed that,with the increased concentration of Danshensu, fluorescence intensity (¦¤¦Ë=15 nm) increased significantly and the maximum emission wavelength was stable at 285 nm,it is right for calculation the binding parameters of Danshensu-BSA. As ¦¤¦Ë=60 nm, the emission spectrum of Danshensu-BSA system showed a blue shift but the fluorescence intensity increased unobviously.The binding parameters of Danshensu-BSA were calculated based on the data of synchronous fluorescence spectra for the first time. The binding constants at 298, 308 and 318 K were 1.43¡Á106, 1.25¡Á106,5.00¡Á105 L/mol, respectively. The thermodynamic parameters (¦¤H=-10.28 kJ/mol, ¦¤S>0£© implied that electrostatic force should be the predominant intermolecular force stabilizing the Danshensu-BSA complex£®