The amino acids and other ampholytes of urine. 2. The isolation of a new sulphur-containing amino acid from cat urine

Abstract

A new S-containing amino acid (felinine) is excreted by the cat in amts. as high as 100-120 mg./day, which is greater in amt. than that of any other single amino acid. Degradative studies with Raney nickel led to the identification of alanine, isoamyl alcohol and H2S indicating that felinine is a S-hydroxyalkyl-cysteine, the alkyl group having the carbon skeleton of iso-pentane. On treatment with mineral acid felinine gives rise to a second S-containing amino acid (C/2), which is believed to be a dicysteine derivative. This substance does not occur as such in cat urine.