D‐Penicillamine—Production and Properties

Abstract The non‐naturally occurring amino acid D ‐penicillamine, originally only of interest as a key substance in the structural elucidation and total synthesis of penicillins is gaining increasing importance as a therapeutic, particularly in the long‐term treatment of rheumatoid arthritis. D ‐Penicillamine which previously was obtained semi‐synthetically by degradation of penicillins can now be totally synthesized using a new process which starts from isobutyraldehyde, sulfur, ammonia, and hydrogen cyanide and yields the racemate which is then selectively resolved. The biochemical behavior of D ‐penicillamine—chelate formation with heavy metal ions, cleavage of disulfide bridges, and condensation with aldehyde groups—affords information related to its therapeutic activity.