Immobilization of ω-transaminases by encapsulation in a sol-gel/celite matrix

Commercially available omega-transaminases omega-TA-117, -113, and Vibrio fluvialis (Vf-AT) have been immobilized in a sol-gel matrix. Improved results were obtained by employing Celite 545 as additive. The immobilized omega-transaminases omega-TA-117, -113, and V. fluvialis (Vf-AT) were tested in the kinetic resolution of alpha-chiral primary amines. In contrast to the free enzyme omega-TA-117. the sol-gel/celite immobilized enzyme showed activity even at pH 11. Recycling of the sol-gel/Celite 545 immobilized omega-transaminase omega-TA-117 was performed over five reaction cycles without any Substantial loss in enantioselectivity and conversion. Finally, the immobilized omega-TA-117 was employed in a one-pot two-step deracemization of rac-mexiletine and rac-4-phenyl-2-butylamine, two pharmacologically relevant amines. The corresponding optically pure (S)-amines were obtained in Lip to 95% isolated yield (>99% ee). (C) 2009 Elsevier B.V. All rights reserved.