Identification of sulfur-containing metabolites of p-dichlorobenzene and their disposition in rats.

Abstract

The structure of 2 sulfur-containing metabolites of the moth repellant p-dichlorobenzene (p-DCB), the distribution of p-DCB and the metabolites in the blood and some tissues, as well as the excretion of the metabolites in the urine and feces of rats were studied. p-DCB was detected in human adipose tissue and blood as a pollutant together with polychlorinated biphenyls. After the oral administration of p-DCB, 2 metabolites emerged in the blood. These metabolites were found for hours after p-DCB had almost disappeared from the blood. It was concluded by comparison of spectral data, TLC and gas chromatogram with those of authentic samples that the metabolites M-1 and M-2 are 2,5-dichlorophenyl methyl sulfoxide and 2,5-dichlorophenyl methyl sulfone, respectively. The concentration of M-1 in the blood was higher than M-2 for 12 h after dosing p-DCB, but the blood level of M-2 prevailed thereafter, and maintained an appreciable level even after 120 h. The storage of p-DCB in the adipose tissue and the slow excretion rates of M-1 and M-2 may be responsible for the existence of the metabolism in the blood for long hours. The highest concentration of M-1 was found in the kidney and that of M-2 was in the blood for the period observed. The excretion of M-1 and M-2 in the urine was much less than that of 2,5-dichlorophenol, the major metabolite.