Interaction of flavonoids in Lonicera syringantha Maxim.with bovine serum albumin

Aim:To study the interaction of flavonoids with bovine serum albumin(BSA).Methods:Spectrophotometry and fluorescence quenching method were employed to characterize the possible interaction between flavonoids and BSA.The binding constant and distance between flavonoids and BSA were calculated,and the main type of binding force was determined based on thermodynamic parameters.Results:Flavonoids could insert into the hydrophobic pockets of BSA,thereby quenching the inner fluorescence of BSA by forming the flavonoids-BSA complex.Both static quenching and nonradiative energy transferring were confirmed to result in the fluorescence quenching.It was also found that the hydroxide radical of the molecular structures affected the quenching efficiency.The binding process of flavonoid molecule with BSA was a spontaneous molecular interaction procedure in which entropy increased.Conclusions:There exists a relatively strong binding force between flavonoids and BSA,due to hydrophobic force as well as dipole-dipole force.