Beta-peptide

β-peptides consist of β amino acids, which have their amino group bonded to the β carbon rather than the α carbon as in the 20 standard biological amino acids. The only common naturally occurring β amino acid is β-alanine; although it is used as a component of larger bioactive molecules, β-peptides in general do not appear in nature. For this reason β-peptide-based antibiotics are being explored as ways of evading antibiotic resistance. Early studies in this field were published in 1996 by the group of Dieter Seebach and that of Samuel Gellman.

In α amino acids (molecule at left), both the carboxylic acid group (red) and the amino group (blue) are bonded to the same carbon center, termed the α carbon (${\displaystyle \mathrm {C} ^{\alpha }}$) because it is one atom away from the carboxylate group. In β amino acids, the amino group is bonded to the β carbon (${\displaystyle \mathrm {C} ^{\beta }}$), which is found in most of the 20 standard amino acids. Only glycine lacks a β carbon, which means that β-glycine is not possible.

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