Abstract
A new cyclic imino acid, [image] azetidine-2-carboxylic acid, was isolated from leaves of Convallaria majalis (lilly-of-the-valley) and its structure confirmed by comparison with the synthetic compound. The new amino acid constituted 75% of the total amino-imino acid in the leaves and seed of C. majalis. It was the major constituent in some other Liliaceae and Agavaceae. It is suggested that the acid may be formed from aspartic acid, homo-serine and diaminobutyric acid.