Methods of peptide sequencing. Part II. Cyclisation of N-2-amino-6-ntirophenyl and N-3-amino-2-pyridyl derivatives of amino-acids and peptides

Abstract

Peptides and amino-acids were treated with either 1-fluoro-2,6-dinitrobenzene or 2-fluoro-3-nitropyridine to give N-nitroaryl derivatives. The latter were reduced by transfer catalysis to N-aminoaryl derivatives, which cyclised with, in the peptide case, release of the peptide minus its N-terminal amino-acid residue. The cyclised materials were readily identified by mass spectrometry. This cycle of operations was used to obtain a partial sequence of amino-acids in a peptide.