The quinobenzoxazines: relationship between DNA binding and biological activity

The quinobenzoxazine compounds, derived from antibacterial quinolones, is a ctive in vitro and in vivo against murine and human tumors. In this contrib ution, we show that the relative DNA binding affinity of the quinobenzoxazi ne compounds correlates with their cytotoxicity, their ability to inhibit g yrase-DNA complex formation, and the decatenation of kinetoplast DNA by hum an topoisomerase II, DNA binding studies with the descarboxy-A-62176 analog ue indicate that the P-keto acid moiety of the quinobenzoxazine compounds p lays an important role in their interaction with DNA.