carboxylic acid amino acid carboxamide N-acyl-amino acid acyl-amino-acids N-acyl amino acid CHEBI:51569 N-acylamino acids acyl-amino-acid A carboxamide resulting from the formal condensation of a carboxylic acid with the amino group of an amino acid. CHEBI:21653 N-acyl-amino-acid N-acyl amino acids N-acylamino acid CHEBI:22226 acylamino acids chebi_ontology N-acyl-amino-acids amino acid derivative