Comparative metabolism of six ethoxychlor analogs and DDT in DDT-resistant and susceptible strains of the house fly Musca domestica L

The metabolic fate of six ³H-ring-substituted ethoxychlor analogs with altered aliphatic moieties and [¹⁴C]p,p′-DDT was investigated in susceptible and DDT-resistant strains of the house fly Musca domestica Linnaeus. The chloroalkane analogs, dichloroethane, chloropropane, and dichloropropane were primarily metabolized to the corresponding dehydrochlorinated products. This pathway was relatively more prominent in the resistant strain than in the susceptible strain. Biotransformation and detoxication of the isobutane, nitropropane, and neopentane derivatives was through microsomal oxidation (O-deethylation) of aryl ethoxy degradophores, and oxidation of the aliphatic moieties to produce the corresponding benzophenones, with no substantial differences between the resistant and susceptible strain. There was a strong correlation between the Taft ($\text{σ}{}^1$) values for the altered aliphatic moieties of chloroalkane analogs and their rate of dehydrochlorination in both the strains. These results suggest the importance of altered aliphatic moieties in developing resistance-proof DDT derivatives.