Untersuchungen zur Frage der Lanthionin-Bildung aus Wolle und Cystin

Abstract

The formation of lanthionine (1) from cystine and certain of its derivatives is studied as a model system for the formation of (1) from wool. Treatment of cystine with alkali yields (1). The addition of dl-cysteine to N-acetyl-alpha-aminoacrylic acid yields a mixture of meso- and dl-lanthionine. (1) Is oxidized by bromine to a sulfoxide. It also forms a sparingly soluble copper complex. Evidence is presented for the view that dehydroalanine is an intermediate in the formation of (1) from cystine; this is then stabilized either to alanine or to (1). The synthesis, properties and reactions of S-carboxymethyl-and S-beta-and S-alpha-carboxyethylcysteine have been investigated, as has the decomposition by acid of N-acetyl-alpha-amino-acrylic acid, which has been used in the thioether synthesis. It is held that there is no fundamental difference between the lability of the -SS- linkages in cystine and wool. Cleavage always results in the formation of mercap-to-groups, H2S and elementary sulfur.