Multiple spectroscopic and computational studies on binding interaction of 2-phenylamino-4-phenoxyquinoline derivatives with bovine serum albumin.

Binding characteristics of potent non-nucleoside HIV-1 reverse transcriptase inhibitors, 4-(2',6'-dimethyl-4'-formylphenoxy)-2-(5″-cyanopyridin-2″ylamino) quinoline (1) and 4-(2',6'-dimethyl-4'-cyanophenoxy)-2-(5″-cyanopyridin-2″ylamino) quinoline (2), to bovine serum albumin (BSA) under simulative physiological conditions were investigated by multiple spectroscopic and computational methods. The experimental results demonstrated that (1) and (2) bound to BSA at site III (subdomain IB), and quenched BSA fluorescence through a static quenching process. The binding interaction of (1) or (2) to BSA forms stable complexes with the binding constants (K) at the level of 10 L/mol and the number of binding site was determined to be 1 for both systems, indicating that new synthesized compounds occupied one site in BSA with moderate binding affinities.