https://doi.org/10.1351/goldbook.P04479
@A00266@ derived from two or more amino carboxylic acid molecules (the same or different) by formation of a @C01384@ from the carbonyl carbon of one to the nitrogen atom of another with formal loss of water. The term is usually applied to structures formed from α-amino acids, but it includes those derived from any amino carboxylic acid.
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(R may be any organyl group, commonly but not necessarily one found in natural amino acids).