VOLTAMMETRIC STUDIES OF THE INTERACTION OF DAUNOMYCIN ANTICANCER DRUGWITH 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 cons iderably after intercalating to the large, slowly diffusing DNA, and t he apparent diffusion coefficients of daunomycin and daunomycin-DNA ad duct, 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 curr ents 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 con centration 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 an d reproducibility for the determination of DNA. Moreover, the binding constant and binding-site size of the daunomycin-DNA interaction, obta ined 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 r ights reserved.