What is "imino acid"

n. 1 (context obsolete chemistry English) imidic acid 2 (context organic chemistry English) Any carboxylic acid having an imino substituent.

In chemistry, an imino acid is any molecule that contains both imino (>C=NH) and carboxyl (-C(=O)-OH) functional groups.

Imino acids are related to amino acids, which contain both amino (-NH) and carboxyl (-COOH) functional groups, differing in the bonding to the nitrogen.

The D-amino acid oxidase enzymes are able to convert amino acids into imino acids. Also the direct biosynthetic precursor to the amino acid proline is the imino acid (S)-Δ-pyrroline-5-carboxylate (P5C).