The investigation of the interaction between orientin and bovine serum albumin by spectroscopic analysis.

In this paper, the interaction between orientin and bovine serum albumin (BSA) was examined using fluorescence and absorbance spectroscopy. The analysis of the quenching mechanism was done using Stern-Volmer plots which exhibit upward (positive) deviation. A linear response to orientin was shown in the concentration range between 3 and 50 μM. The experimental results showed the presence of a static quenching process between orientin and BSA. The thermodynamic parameters ΔH, ΔS and ΔG were also calculated and suggested that the hydrophobic and electrostatic interactions played an important role in the interaction between orientin and BSA. Furthermore, the distances between BSA and orientin were determined according to Förster non-radiation energy transfer theory. In addition, the results of the synchronous fluorescence obtained indicated that the binding of orientin with BSA could affect conformation in BSA.