DNA cleavage by a chromium(III) complex

A new Cr(III) complex with the empirical formula [Cr(Schiff base) (H2O)(2)] ClO4, where the Schiff base is 2,3-bis{[(2-hydroxy-4-diethylamino) (phenyl) (methylene)]amino}2-butenedinitrile has been synthesized and characterized spectroscopically. Binding of this complex to DNA has been studied using U V-visible spectroscopy. The complex has been found to bind to the major gro ove of DNA with a binding constant, K = (1.3 +/- 0.2) x 10(3) M-1. The indu ced CD spectrum of the complex in the presence of DNA is also indicative of major groove binding. Gel electrophoresis of plasmid DNA in the presence o f the complex shows that the complex brings about nicking of the DNA. (C) 2 000 Academic Press.