The inhibition by naphthoquinones and anthraquinones of 2-amino-3-methylimidazo[4,5- f  ]quinoline metabolic activation to a mutagen: a structure-activity relationship study

Nine naphthoquinones, 19 anthraquinones, and nine structurally related monoketonic compounds such as anthrone, xanthone, etc., inhibited mutagenicity induced by 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in Salmonella typhimurium TA 98 in the presence of rat liver S9 with distinct structure-activity relationships. A carbonyl function was a prerequisite for antimutagenicity while, in general, anthraquinones (IC50 values: 2.3–>213 nmol/ml top agar) were more potent antimutagens than structurally related monoketonic compounds (IC50 values: 25.3–94.9 nmol/ml top agar) and naphthoquinones (IC50 values: 3.7–90.7 nmol/ml top agar). The parent compounds and methyl substituted derivatives were alr…