Imino acid
![1-Pyrroline-5-carboxylic acid, an N-substituted imino acid](/Images/godic/202502/08/Delta-1-pyrroline-5-carboxylic_acid.svg2303.png")
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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 (-NH2) and carboxyl (-COOH) functional groups, differing in the bonding to the nitrogen.