Studies on l-tyrosine O-sulphate. 2. Identification of p-hydroxyphenylpyruvic acid [35S]sulphate as a metabolite of l-tyrosine O[35S]-sulphate in the rat

Abstract

It has been shown that the unknown sulphate ester excreted when L-tyrosine O[S35]-sulphate is injected into rats (Dodgson et al. 1961) is the [S35]sulphate ester of p-hydroxyphenylpyruvic acid. This compound is unstable and readily undergoes spontaneous conversion into p-hydroxy-benzaldehyde [S35] sulphate at room temperature and alkaline pH and into p-hydroxy-phenylacetic acid [S35]sulphate in the presence of urine at neutral pH. The implications of these various findings are discussed.