Photochemical binding of anthracene and other aromatic hydrocarbons to deoxyribonucleic acid with attendant loss of tritium

Abstract

Anthracene can be bound covalently to calf thymus deoxyribonucleic acid (DNA) by means of long-wavelength u.v. irradiation to a greater extent than any other of seven polycyclic aromatic hydrocarbons investigated. ³H is incorporated into the photochemical product resulting from the irradiation of doubly labelled hydrocarbons and DNA to a lesser extent than is ¹⁴C. In the case of anthracene, the ratio of incorporation of the two isotopes is ca. 3 : 4 and is independent of the extent of irradiation or of hydrocarbon binding. The relevance of these results to the mechanism of binding of hydrocarbons to DNA and to the photodynamic carcinogenicity of anthracene is discussed briefly.