The chemical design of
metal complexes of the type [Cu(phen)(antib)](+) (where antib is a
quinolone or a
fluoroquinolone) has been carried out in an approach to better understand how the coordination of their components affect the activity of
quinolones. The ability of [Cu(phen)(nal)](+) to interact with
DNA in vivo and its capacity to promote the degradation of plasmid and chromosomal
DNA, under reductive conditions has been previously reported. However whether this compound utilizes other intracellular targets to promote bacterial killing was a question that deserved to be answered. In this paper, the studies of the chemical nuclease properties encoded by the
metal complex [Cu(phen)(nal)](+) were extended by using different types of single chain
nucleic acids, i.e, ribosomal and
tumor mosaic virus RNAs as well as
poly-dA-dT. Our results showed that degradation of the
nucleic acids occurred only under reductive conditions. Although MPA and [3-
mercaptoethanol were the chemical reducers that best assisted the nuclease reaction, other
biological compounds such as citric and
succinic acid also were shown to act like reducers in that reaction. All.hough the nuclease activity of [Cu(phen)(nal)](+) was comparable to that exhibited by bis
copper phenanthroline [Cu(phen)z](2+)our results showed that none of the individual components of [Cu(phen)(nal)](+) was able to promote the degradation of either the RNAs or
poly(dA-dT). These results strongly support the hypothesis that the
metal complex [Cu(phen)(nal)] uses not only
DNA but also
RNA as targets to promote bacterial killing.