title: Interaction of aminoacridines with nucleic acids. A pulse-radiolysis study.
abstract: Pulse radiolysis has been used to study the interaction of aminoacridines with nucleic acids. The data confirm that there are two modes of binding. These are: a weak interaction which has a maximum binding ratio of one site per dye; and a strong binding process effected by both electrostatic and Van der Waals interactions. The limit of this latter, strong binding mode is approximately six sites per dye. The radiation-induced transient absorption spectrum of benzoflavine is characterized by a pronounced bleaching at 440 nm, which is quenched by the addition of nucleic acids. Mechanisms have been proposed for the reactions of both eaq-and .OH with benzoflavine which account both for the observed bleaching of benzoflavine solutions and for the protective effect of nucleic acids. It is proposed that eaq-reacts with benzoflavine to form a stable benzoflavine semiquinone radical and that .OH reacts with subsequent formation of a very stable benzoflavine hydroxycyclohexadienyl radical.
mesh_terms: D000166:Acridines; D055598:Chemical Phenomena; D002621:Chemistry; D004396:Coloring Agents; D004247:DNA; D011370:Proflavine; D011675:Pulse Radiolysis; D012313:RNA
chemical_list: D000166:Acridines; D004396:Coloring Agents; D012313:RNA; D004247:DNA; D011370:Proflavine