Induction of increased benzpyrene hydroxylase activity by 2-phenylbenzothiazoles and related compounds.

SUMMARY A study of the relationships between structure of 2-phenylbenzothiazoles and related compounds and their ca pacity to induce increased benzpyrene hydroxylase activity in the liver and lung of the rat has been carried out. Thirty-three compounds have been studied. It has been found that intro duction of an appropriate halogen into the 4'-phenyl position approximately doubles inducing activity compared to unsub stituted 2-phenylbenzothiazole. Other substitutions and modi fications of the molecule result in either lesser increases in inducing activity or, in some instances, reduction or total loss of inducing activity. Most compounds show similar inducing effects on both lung and liver. Some, however, do not. Of the more potent inducers, the compound showing this selective effect to the greatest degree is 2-(4'-cyanophenyl)-benzo thiazole, which has more than double the inducing effect on lung as on liver.