46—AN INVESTIGATION OF THE SULPHUR COMPOUNDS IN ACID HYDROLYSATES OF WOOL

Abstract

Seven ₃₅S-labelled compounds, in addition to ₃₅S-methionine and ₃₅S-cystine, have been found in hydrolysates of ₃₅S-labelled wool by starch chromatography, and four of these, tentatively named SI, S2, S3 and S4, gave the characteristic blue colour by the Shinohara disulphide reaction. The S-compound S2 has been shown to be identical with cysteine, and to be produced mainly by reaction between tryptophan and cystine during hydrolysis. The seventeen other amino acids present in wool hydrolysates do not decompose cystine in boiling HCI. The S-compounds SI, S3 and S4 have not so far been identified, but accounted for about 4·5% of the colour developed when the Shinohara disulphide reaction was carried out on 24-hour acid hydrolysates of wool. The ₃₅S-cystine contained 80% of the total ₃₅S activity.

Starch chromatography of hydrolysates of ₃₅S-labelled wool oxidized wool revealed the presence of four ₃₅S-compounds in addition to ₃₅S-methionine sulphone. ₃₅S-cysteic acid and ₃₅S-cystine. 73% of the ₃₅S activity of the hydrolysate was found in the ₃₅S-cysteic acid.