Enantioresolution of dl-penicillamine

Penicillamine (PenA) is a nonproteinogenic amino acid containing a thiol group. The three functional groups in penicillamine undergo characteristic chemical reactions and differ in their ability to participate in various chemical and biochemical reactions. d-penicillamine is more active pharmacologically, while the l-isomer occurs 'naturally'. This review deals with the enantioresolution of PenA both by direct and indirect methods using liquid chromatography. HPLC separation of its diastereomers prepared with different chiral derivatizing reagents (on reversed-phase columns) and separation of the derivatives prepared with achiral reagents (on chiral columns or via ligand exchange mode) has been discussed. Separation of enantiomers tagged with achiral reagent (to add a chromophore for ehanced detection) when there is no diastereomer formation has been considered separately. In addition, application of PenA and its derivatives as chiral selector for enentioresolution of certain other compounds has also been discussed.