Thin-layer chromatography for detection of peptide cleavage or integrity during reactions of the Z-alanylglycines with aniline or phenylhydrazine under papain catalysis.

Z-l-Ala-gly and Z-dl-ala-gly can yield anilides and phenylhydrazides through peptide cleavage or peptide integrity during papain-catalyzed reactions with aniline (NH2Ph) or phenylhydrazine (NH2NHPh). Since Z-d-ala-gly yielded only uncleaved Z-d-ala-gly-NHPh or Z-d-ala-gly-NHNHPh, these were used as standards in thinlayer chromatography (TLC) for detecting integrity. Known Z-l-ala-NHPh and Z-l-ala-NHNHPh were the standards for cleavage. Depending on the time of incubation, cleaved or unsplit products, or both, were readily detected. The solvent systems that were used for TLC were also effectively employed for separations of reasonable amounts of mixtures of cleaved and uncleaved products through thick-layer chromatography on Chrom AR. This was followed by isolation of the separated components.