Peptide Metal–Organic Frameworks for Enantioselective Separation of Chiral Drugs

We report the use of a chiral Cu­(II) 3D metal–organic framework (MOF) based on the tripeptide Gly-l-His-Gly (GHG) for the enantio­selective separation of met­amphet­amine and ephedrine. Monte Carlo simulations suggest that chiral recognition is linked to preferential binding of one of the enantiomers as a result of either stronger or additional H-bonds with the framework that lead to energetically more stable dia­stereo­meric adducts. Solid-phase extraction of a racemic mixture by using Cu­(GHG) as the extractive phase permits isolating >50% of the (+)-ephedrine enantiomer as target compound in only 4 min. To our knowledge, this represents the first example of a MOF capable of separating chiral polar drugs.