Studies of fatty acid oxidation. 2. The effect of alkylthio fatty acids on acetylation reactions

I954 2. Sodium methylthiopropionate (0-02M) and methylthioacetate (0-02M) both inhibited the oxidation of sodium pyruvate (002M) in rat- kidney slices, but had no effect on the oxidation of the sodium salts of carboxylic acids that were tested.Pyruvate oxidation in rat-brain homogenate was not effected.3. All the alkylthio fatty acids examined in- hibited the D-amino acid oxidase of rat-kidney homogenate but had no effect on several other enzyme systems that were examined.4. The oxidation ofethylthio-acetate, -propionate and -butyrate was studied using [carboxy-14C]labelled substrates.Evidence is presented which indicates that these compounds are oxidized in a manner analogous to the oxidation of the unsub- stituted fatty acids.5.A scheme has been outlined to explain the metabolism of the alkylthio fatty acids and the production of mercaptans.We wish to thank Professor J. H. Quastel, F.R.