Voltammetric studies of the interaction of daunomycin anticancer drug with DNA and analytical applications

The variations in the cyclic voltammetric behavior of daunomycin in an aqueous medium on addition of DNA have been studied and utilized for the quantitation of DNA. The peak current of daunomycin decreased considerably after intercalating to the large, slowly diffusing DNA, and the apparent diffusion coefficients of daunomycin and daunomycin-DNA adduct, determined by rotating disk electrode experiment, were 8.77 x 10(-6) and 6.20 x 10(-7) cm(2) s(-1), respectively. The anodic peak currents of daunomycin decreased linearly correlated to the concentration of DNA in the 0-28, 0-302 and 453-1042 mu g ml(-1) ranges when the concentration of daunomycin was fixed at 1.01 x 10(-5), 1.01 x 10(-4) and 5.05 x 10(-4) M, with the detection limits of 2.4, 37.5 and 372.5 mu g ml(-1), respectively. The proposed method exhibited good recovery and reproducibility for the determination of DNA. Moreover, the binding constant and binding-site size of the daunomycin-DNA interaction, obtained by a titration curve and nonlinear regression analysis, were 2.35 x 10(5) M-1 and 6, respectively. (C) 1998 Elsevier Science B.V. All rights reserved.