Isotactic Polyethylenimines Induce Formation of l-Amino Acids in Transamination

Isotactic polyethylenimines with (S)-benzyl side chains were synthesized from 4-(S)-4-benzyl-2-oxazolines. When α-keto acids were subjected to transamination in the presence of this polymer, and a pyridoxamine coenzyme modified with hydrophobic chains, enantioselectivity toward the natural isomer (l > d) was observed, followed by racemization of the amino acid products. However, the racemization did not occur when the coenzyme was covalently attached to the polymer.