Interaction between felodipine and bovine serum albumin: fluorescence quenching study

Abstract

The fluorescence quenching spectrum of bovine serum albumin (BSA) was investigated in the presence of felodipine (FLD) by spectroscopic methods including fluorescence spectroscopy and UV-Vis absorption spectroscopy. Stern-Volmer quenching was successfully applied and the corresponding thermodynamic parameters, namely enthalpy change (DeltaH), free energy change (DeltaG) and entropy change (DeltaS) at different temperatures (304, 314 and 324 K) were calculated according to the Van't Hoff relation. This revealed that the hydrophobic interaction plays a major role in stabilizing the complex. The fluorescence spectrum of BSA was studied in presence of various concentrations of SDS surfactant. The distance (r) between donor (BSA) and acceptor (FLD) was obtained according to fluorescence resonance energy transfer (FRET). The synchronous fluorescence spectroscopy was used to investigate the effect of FLD on BSA molecule. The result shows that the conformation of BSA was changed in the presence of felodipine.

The influence of flavonoids on the binding of pantoprazole to bovine serum albumin by spectroscopic methods: With the viewpoint of food/drug interference

“…In the experiments, flavonoid was first added into the BSA solution for some time, and then pantoprazole was added, therefore, flavonoid first combined with BSA to form flavonoid-BSA complex, and then pantoprazole reacted with flavonoid-BSA complex. Overall, the decreased binding constants of pantoprazole in the presence of flavonoids were consistent with two distinct interpretations (Mote et al, 2010;Zhang, Shi, Huang, Chen, & Peng, 2011): (1) a competitive binding in the flavonoid high-affinity site; (2) a noncompetitive binding in a different albumin site. It was a puzzle about whether the presence of flavonoids affected the binding mode of pantoprazole with BSA.…”

“…The binding constant (K) and binding sites (n) are calculated by the double-logarithm equation for static quenching (Mote, Bhattar, Patil, & Kolekar, 2010):…”

Impact of Solubilizing Additives on Supersaturation and Membrane Transport of Drugs

“…(45). As a result of this binding (46), the equilibrium solubility of felodipine is increased by a factor of around 35 when 0.1% BSA is added to the solution; this factor increases to about 42 when the BSA concentration is increased to 1%. If Eq.…”

Spectroscopic Investigation of Interaction Between Carbon Quantum Dots and D-Penicillamine Capped Gold Nanoparticles

“…Therefore, it is essential to know the type of fluorescence quenching and mechanism of energy transfer. The type of fluorescence quenching was ascribed by the well known Stern-Volmer equation [50,51].…”