Abstract
As a part of the biological investigations on deoxyribonucleic acid (DNA)-interacting aminoquinones, the interaction of 2-hydroxyamino-1, 4-naphthoquinone (HANQ) with nucleic acids and its biological actions were studied. 1. Spectroscopic determinations indicated that HANQ interacted with DNA without effect by Mg2+. The interaction sites in DNA was estimated to be the purine bases from the difference spectra with nucleic acid derivatives. 2. HANQ inhibited thymidine incorporation into DNA in Ehrlich ascites carcinoma, rather than in E. coli cells, to a higher extent than mitomycin C. The precursor incorporation into RNA and proteins in the carcinoma was less inhibited ; the inhibition resulted possibly from a secondary action of HANQ. 3. An antitumor effect of HANQ was observed on Ehrlich ascites carcinoma, ascites sarcoma-180, and L-1210 leukemia at doses less than half of the LD50 (mouse, i.p., 318 mg/kg). 4. The biological actions of HANQ was discussed in analogy to 4-hydroxyamino-quinoline-1-oxide (4HAQO), a proximate carcinogen of 4-nitroquinoline-1-oxide (4NQO).
