Hydrolysis of 5,5'-di-substituted hydantoins with linear and cyclic side chains, to produce the corresponding alpha,alpha-dialkylated amino acids and 1-aminocycloalkane-1-carboxylic acids, using an enzyme preparation from lentil (Lens esculenta) seeds is reported for the first time. This method could be developed on a large scale and should be of interest to the chemical and pharmaceutical industries.