Hydroxynitrobiphenyls produced by photochemical reaction of biphenyl in aqueous nitrate solution and their mutagenicities.

Abstract

From the photoreaction products of biphenyl in aqueous nitrate solution, the following 8 hydroxynitrobiphenyls were isolated by silica gel column chromatography and TLC on silica gel and polyamide plates: 4-hydroxy-3,5-dinitrobiphenyl (F1(2)or); 4,2''-dihydroxy-3,3''-dinitrobiphenyl (F4(1)-3); 4-hydroxy-3,3''-dinitrobiphenyl (F4(1)-4b); a hydroxydinitrobiphenyl (F4(1)-5a; 4,4''-dihydroxy-3,3''-dinitrobiphenyl (F4(1)-5b); a dihydroxydinitrobiphenyl (F4(1)6); 2-hydroxy-3-nitrobiphenyl (F5(1)); and 4-hydroxy-3-nitrobiphenyl (F5(2)). Among these compounds, four dinitro compounds, F1(2)or, F4(1)-4, F4(1)-5a and F4(1)-6, exhibited mutagenicity toward Salmonella typhimurium TA98 without S-9 mix. The major products in this reaction were nitrophenylphenols, F5(1) and F5(2), and these were non-mutagenic. The major mutagens, F4(1)-5a and F4(1)-6, were produced in such small amounts that the exact structures could not be determined. The mechanism of production of these hydroxynitrobiphenyls is discussed on the basis of the results of analysis of the reaction mixture by high-performance liquid chromatography.