Nmr study of poly(aspartic acid). II. α- and β-Peptide bonds in poly(aspartic acid) prepared by common methods

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Abstract

The nature of peptide bonds in poly(aspartic acid) prepared by debenzylation of poly(β-benzyl-L-aspartate) under various conditions has been studied by means of nmr spectroscopy. It was established that the majority of the polymers prepared, as well as the commercially obtained polymer, contained aspartic acid linked in both α- and β-peptide bonds. The purest polymer, having practically undetectable amounts of β-bond, was prepared by debenzylation by HBr in trifluoroacetic acid. It was established that the β-bonds are formed via succinimides.

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