Photomutagenicity of N-nitrosoproline dissolved in non-aqueous solvent, oleic acid.

In the present study, we investigated the genotoxicity of the active products formed from N-nitrosoproline (NPRO) dissolved in oleic acid following ultraviolet A (UVA) irradiation, bypassing the need for metabolic activation. We previously demonstrated the photomutagenicity of NPRO dissolved in a phosphate-buffered solution. It has been suggested that the association of the nitrosamine group with acid ions facilitates rapid photodissociation and photoactivation.

Effects of bromide upon reaction of nucleosides with hydrogen peroxide induced by ultraviolet light.

When ultraviolet light was irradiated on a neutral solution of deoxynucleosides and hydrogen peroxide, concentrations of all the deoxynucleosides decreased greatly. Addition of bromide in the system suppressed the reactions of 2'-deoxycytidine, 2'-deoxythymidine, and 2'-deoxyadenosine, but not that of 2'-deoxyguanosine. Addition of hydroxyl radical scavengers suppressed the reaction.