IDENTIFICATION OF SULFUR-CONTAINING METABOLITES OF PARA-DICHLOROBENZENE AND THEIR DISPOSITION IN RATS

The structure of two sulfur-containing metabolites of p-dichlorobenzene (p-DCB), the distribution of p-DCB and the metabolites in the blood and some tissues, and the excretion of the metabolites in the urine and feces of rats were studied. After the oral administration of p-DCB, two metabolites emerged in the blood. And these metabolites were found for many hours even after p-DCB had almost disappeared from the blood. It was concluded by comparison of spectral data, thin layer chromatogram 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 that of M-2 for 12 hr after dosing p-DCB, but the blood level of M-2 prevailed thereafter, and maintained an appreciable level even after 120 hr. 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 metabolites 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. © 1979, The Pharmaceutical Society of Japan. All rights reserved.