Azetidine-2-carboxylic acid in garden beets (Beta vulgaris).

We report the presence of substantial concentrations of l-azetidine-2-carboxylic acid (l-Aze) in garden or table beet (Beta vulgaris) and note the potential role of beets in the pathogenesis of congenital and acquired disorders of man and other animals. l-Aze, a homologue of proline, has been found to misincorporate in proteins in mammals and cause fetal malformations.