Abstract
This paper reports the purification of synthetic protected peptides on a preparative scale by means of adsorption chromatography on silica gel 60 columns. The protected peptides described were precursors of a free asymmetrical cystine peptide corresponding to the insulin sequence A18–21-B19–26 and were obtained in analytically pure form. Selection of solvent systems for isocratic or stepwise elution depended largely on RF data obtained from thin-layer chromatograms which were used for monitoring and optimizing synthetic reactions.