Synthesis of novel 3-fluorooxindoles and their affinity probing with serum albumin: Using multi-spectral, electrochemical, and molecular docking

Abstract Here we synthesized four 3-fluorooxindole derivatives and investigated their affinity interactions with serum albumin by using multi-spectral, electrochemical, and molecular docking. Fluorescence spectroscopy results revealed the affinity of 3-fluorooxindole derivatives and serum albumin. UV spectroscopy showed the type of quenching for both were static quenching, which was proved by temperature dependence experiments and time-resolved fluorescence. Electrochemical experiment results suggested the binding constant of 3-fluorooxindole derivatives and serum albumin was 103–104 by the order of magnitude. Synchronous fluorescence spectroscopy and infrared spectroscopy demonstrated the effect on the secondary structure of serum albumin in the presence of 3-fluorooxindole units. Furthermore, molecular docking and site competition experiments result determined that 3-fluorooxindole derivatives bind to site I of serum albumin. Finally, the interactions between 3-fluorooxindole derivatives and serum albumin were investigated by various methods and summarized the effects of substituents in 3-fluorooxindole derivatives on serum albumin interactions. These results provide a reference for the design of subsequent synthesis of 3-fluorooxindole derivatives and theoretical support for the development of related fluorine-containing drugs.