3-Hydroxyflavone-bovine serum albumin interaction in dextran medium

Abstract

A bioactive flavonol, 3-hydroxyflavone (3-HF), in systems based on dextran 70 (Dx70, an important bio-relevant polysaccharide) and bovine serum albumin (BSA, a carrier protein) was studied by fluorescence and circular dichroism. Changes produced by different concentrations of Dx70 on the fluorescent characteristics of 3-HF and on the excited-state intramolecular proton transfer (ESIPT) process were studied. The influences of 3-HF binding and of Dx70 on the secondary structure of BSA were investigated by circular dichroism spectroscopy. The influence of temperature (30-80 °C range) on the intrinsic tryptophan fluorescence in 3-HF/BSA/Dx70 systems was investigated. The results are discussed with relevance to 3-HF as a sensitive fluorescence probe for exploring flavone-protein interactions in plasma expander media and for its biological evaluation