WANI Dictionary

Aromatic amino acid

Aromatic amino acids typically include tyrosine, phenylalanine, and tryptophan.

In a broader sense, histidine can also be considered an aromatic amino acid. This interpretation is related to the definition of "aromatic" in chemistry. Traditionally, "aromatic" referred to compounds with a structure typified by benzene [1], which restricted aromatic amino acids to tyrosine, phenylalanine, and tryptophan. However, the definition of "aromatic" has expanded to include cyclically conjugated molecular entities that are significantly more stable than hypothetical localized structures [1]. With this broader definition, histidine is also considered an aromatic amino acid.

Definitions in the literature