A spectroscopic investigations of anticancer drugs binding to bovine serum albumin

The binding of anticancer drugs (i) Uracil (U), (ii) 5-Fluorouracil (5FU) and (iii) 5-Chlorouracil (5CIU), to bovine serum albumin (BSA) at two levels of temperature was studied by the fluorescence of quenching method. UV/Vis, time-resolved fluorescence, Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (H-1 NMR) and scanning electron microscope (SEM) analyses were also made. Binding constants (K-a) and binding sites (n) at various levels of temperature were calculated. The obtained binding sites were found to be equal to one for all the three quenchers (U, 5FU and 5CIU) at two different temperature levels. Thermodynamic parameters Delta H, Delta G and Delta S have been calculated and were presented in tables. Change in FTIR absorption intensity shows strong binding of anticancer drugs to BSA. Changes in chemical shifts of NMR and fluorescence lifetimes of the drugs indicate the presence of interaction and binding of BSA to anticancer drugs. 1H NMR spectra and SEM photographs also conform this binding. (C) 2011 Elsevier B.V. All rights reserved.