posted on 2023-11-20, 16:55authored byDaniel
A. Grajales-Hernández, Eleftheria Diamanti, Riccardo Moro, Susana Velasco-Lozano, Elisabet Pires, Fernando López-Gallego
Production
of enantiomerically pure molecules is of utmost importance
in the pharma industry. In this context, biocatalysis emerges as an
alternative to conventional chemical methods due to the exquisite
selectivity and specificity underlying the enzymes. In this work,
we design a multienzymatic system to perform the deracemization of
alkyl glyceryl ethers as potential building blocks for the synthesis
of drugs. The key to success in this route is controlling the spatial
organization of the enzymes involved in the cascade through their
immobilization on porous carriers. By fine tuning the intraparticle
organization of an enzymatic cascade comprising an (S)-selective glycerol dehydrogenase from Bacillus stearothermophilus and an (R)-selective ketoreductase from Lactobacillus kefir, we performed the oxidoreductive
deracemization of rac-alkyl/aryl glyceryl ethers
with a yield up to 100% and enantiomeric excess e.e. > 99%, otherwise
impossible using a soluble system. Remarkably, we find that optimal
spatial assembly of the biocatalyst ameliorates the inhibition phenomena
experimented by the system and increases the deracemization rate by
4-fold. Finally, integrating an enzymatic nicotinamide adenine dinucleotide
oxidized disodium salt (NAD+) regeneration system to the
heterogeneous biocatalyst, we intensified the process by reusing it
in discontinuous and consecutive batch cycles and scaling the reaction
up to 250 mM substrate, achieving 100% yield and e.e. > 99%.