Interaction of novel tris-intercalators with DNA. Spectrofluorometric studies.

Novel DNA binding ligands (1 and its stereoisomer 2) which contain three potentially intercalating units in a linear molecular skeleton were prepared. From a study of the displacement of ethidium bromide from several natural and synthetic polynucleotides, both compounds 1 and 2 were found to show an AT base-pair preference in the interaction with DNAs with 2 a slightly higher affinity for DNA. This result is in sharp contrast to that for acridine and anthraquinone, because these two compounds exhibit a GC-preference.