imino acids

https://doi.org/10.1351/goldbook.I02959
  1. An obsolete term, which should not be used, for imidic acids.
  2. Any carboxylic acids having an imino substituent, $\ce{HN=}$, replacing two hydrogens. A shortened form of imino carboxylic acid.
  3. Obsolescent term for azaalkanoic acids and azacycloalkane-2-carboxylic acids, e.g. proline:
    molecule
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1343 [Terms] [Paper]