Mimics of Transaminase Enzymes

Pyridoxamine has been attached to the primary side and to the secondary side of β-cyclodextrin; the resulting compounds convert α-keto acids to amino acids with substrate selectivity and some stereoselectivity. Pyridoxamine has also been attached to a synthetic macrocycle; the attached binding group showed substrate selectivity. Chains carrying catalytic basic groups have been attached to pyridoxamine; appropriate systems catalyze the prototropic rearrangement characteristic of transamination. A catalyzed HCl elimination involving chloropyruvic acid was also observed. A tetrahydroquinoline system related to pyridoxamine was synthesized to permit the stereochemically defined placement of a basic catalytic group. This converted keto acids to amino acids with good stereoselectivity for the formation of optically active products.