[Direct transition of S-acetamidomethyl-protected peptide 593-603 of HIV-2 gp41 into a cyclic disulfide using iodine. Study of side reactions].

Removal of Acm-protecting group from thiol functional groups of Cys residues with simultaneous disulfide bridge formation by iodine in acetic acid was studied in the course of the synthesis of a peptide fragment corresponding to 593-603 sequence of HIV-2 gp41 glycoprotein. The excess iodine influence on the cyclization process was investigated. By-products of the oxidative disulfide formation were isolated, and their structures were elucidated by means of amino acid and elemental analyses, mass spectrometry, NMR, and UV-spectroscopy.