title: Continuous Reusability using Immobilized HasApf in Chemoenzymatic Deracemization: A New Heterogeneous Enzyme Catalysis.
abstract: This study found that the calibration curve of heme acquisition system A (HasA, a new reactive active species) immobilized by a porous ceramic particle (ImHApf; immobilized HasA fromPseudomonas fluorescens) can be constructed in the range of 1750-1450 cm-1using Fourier transform infrared spectroscopy (FTIR) analysis, and evaluated its catalytic efficiency. In the asymmetric oxidation ofrac-1-(6-methoxynaphthalen-2-yl)ethanol (rac-1: a naproxen precursor), a product ketone from the (R)-isomer is desymmetrized using NaBH₄ and continuously reused even if treated with an organic solvent in 50 mM glycine-NaOH buffer at 40 °C in the absence of nicotinamide adenine dinucleotide (NAD(P)), leading to >99% enantiomeric excess and >90% chemical yield; the activity was calculated at 0.74 ± 0.03 mU/(mg·min) and the turnover number was determined to be approximately 2 × 10⁶. It was confirmed that the othersec-alcohols such asrac-1-(2-naphthyl)ethanol (rac-2) andm- andp-substitutedrac-1-phenyl ethanols (rac-3ab-6ab) using ImHApf can also yield a single stereoisomer from a racemate. Therefore, HasA immobilization can be expected to become an important tool for building an environmentally friendly system that promotes industrial sustainability.
authors: Sanyo Shokuhin Co., Ltd. R & D, 555-4 Asakura, Maebashi, Gunma 371-0811, Japan. hnagaoka@sanyofoods.co.jp.
authors: Hiroyuki
authors: H
authors: Nagaoka
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D011551:Pseudomonas fluorescens / Q000201:enzymology*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004800:Enzymes, Immobilized
keywords: chemoenzymatic deracemization; continuous reusability; immobilized HasA; iron electron-transfer system; porous ceramic particle