Structure-toxicity relationship of aliphatic nitriles

Acute toxicity, in vitro metabolism and structure-toxicity relationship of aliphatic mononitriles were examined in mice pretreated with carbon tetrachloride (CCl4). The LD50 in mice pretreated with CCl4 (LD50-CCl4) was increased in most nitriles compared to that in untreated animals (LD50-cont.) with different degrees among compounds. Microsomal metabolism of nitriles to CN- was completely inhibited when microsomes were prepared from livers of mice pretreated with CCl4. Log (1/LD50-CCl4) was a linear function of partition coefficient, log P, i.e., log (1/LD50-CCl4) = -0.371 log P-0.152, and the equation was statistically significant (P less than 0.01), provided aceto- and 3-hydroxypropionitrile were omitted from the analysis. These two compounds seem to be different from the others in exerting the biological effect.