Carcinogenicity of derivatives of 7,12-dimethylbenz(a)anthracene.

Eleven derivatives of 7,12-dimethylbenz(a)anthracene were tested for carcinogenicity in Sprague-Dawley female rats by the s.c. injection of 1.0 or 0.1 mg of compound dissolved in 0.1 ml of sesame oil on alternate days for 20 doses. Eight derivatives [7-hydroxymethyl-12-methyl-, 7-formyl-l 2-methyl-, 7-methoxymethyl-l 2-methyl-, 7-acetoxymethyl-l 2-methyl-, 7-benzoyloxymethyl-l 2-methyl-. 7-iodomethy 1-12-methyl-, 7-bromomethyl-l 2-methyl,and 7-chloromethyl-l 2-methylbenz(a)anthracene] were carcinogenic at the 1-mg dose level, and 5 [benzoyloxymethyl-12-methyl-, 7-formyl-l 2-methyl-, 7-bromomethyl-l 2methyl-, 7-hydroxymethyl-l 2-methyl-, and 7-iodomethyl-12methylbenz(a)anthracene] were carcinogenic at the 0.1-mg dose level (200 days of observation). These observations suggest that the formation of 7-hydroxymethyl-l 2-methylbenz(a)anthracene may be the first step in the chain of events which result in cancer caused by these polycyclic hydro carbons.