The oxidation of dimethylthetin and related compounds to sulphate in the rat

Abstract

Dimethylthetin chloride administered to pairs of rats was oxidized to inorganic sulphate to the extent of 57.6-68.7% when given orally and 37.4-4.57.1% when injected subcutan. Of 7 other sulphonium compounds only ethylmethylthetin, dimethyl-beta-propiothetin and sulphocholine were oxidized in this way, indicating that the formation of sulphate is not a general mode of metabolism for this type of compound. In the limited series of compounds studied, oxidation to sulphate was confined to sulphonium salts which are able to act as biological methyl donors, and it is suggested that demethylation is an initial and obligatory step in their catabolism to sulphate. Possible intermediates in the oxidation are discussed.