Abstrato

Investigation of the competition interactions between artificial food dyes and ciprofloxacin hydrochloride with bovine serum albumin by spectrofluorimetric method

Baohong Chong, Baosheng Liu, Zhiyun Li, Ying Guo, Lihui Zhang

The competition interactions between ciprofloxacin hydrichloride(CPFX) and artificial food dyes, such as tartrazine (TTZ), sunset yellow (SY), and erythrosine (ETS), with bovine serumalbumin (BSA) were investigated by spectrofluorimetric method in the aqueous solution of pH = 7.40. Results showed that CPFX caused the fluorescence quenching of BSA through a static quenching procedure and the primary binding site was located at subdomain IIAof BSA(site I).According to the calculated thermodynamic parameters, it confirmed that CPFXbound toBSAby electrostatic interaction. In addition, the colorants affected the formation of BSA-CPFX complex. This resulted in an increase of the free, biological active fraction of CPFX. The binding distance of BSA-CPFX systems was evaluated according to F¨orsterÂ’s theory. Results suggested that the binding distance were increased in the presence of synthetic food colorants.