Publications by authors named "Hiroyuki Nagaoka"

The aim of this study was to propose an alternative route for preparing chiral β- and α-ionols by asymmetric oxidation with a heme acquisition system A (HasA) derived from symbiotic fluorescent bacteria as a biocatalyst. The HasA (6 g) in distilled water (300 mL) was stirred at 1150 rpm for 1 day at 40°C. Subsequently, a secondary alcohol (0.

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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 from ) can be constructed in the range of 1750-1450 cm using Fourier transform infrared spectroscopy (FTIR) analysis, and evaluated its catalytic efficiency. In the asymmetric oxidation of -1-(6-methoxynaphthalen-2-yl)ethanol (-: a naproxen precursor), a product ketone from the ()-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.

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A PP (pea)-HASApf-redoxin complex eluted from encapsulated PP gel with aeration displays asymmetric oxidation activity over 200 times greater than that of a similar protein expressed by E. coli cells. The intermediate spin, identified in the ESR spectrum, appears at g = 4.

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A protein complex (PC) suspension exhibits asymmetric biooxidation activities in the absence of any added cofactor such as NAD(P)(+) or FAD. It can be extracted from pea protein (PP)-gel (PP encapsulated with Ca(2+) alginate gel and aerated in air for several hours) using hot water by rotary shaking and powdered by the following three steps: (1) forming precipitates from the suspension using 30% (w/v) aqueous (NH(4) )(2) SO(4) , (2) crosslinking the precipitates with 0.25% (v/v) GA, and (3) preparing the cross-linked powder by freeze-drying.

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We found that the levels of bioactive products from wheat can be increased dramatically by manipulating germination conditions and taking advantage of the activity of endogenous enzymes. The yield of phytic acid (IP(6)) from wheat germinated in the presence of high, controlled levels of dissolved oxygen (188 +/- 28 mg/100 g wheat) was almost three times greater than that from wheat germinated with no supplemental oxygen (74 +/- 10 mg/100 g wheat). The yield of gamma-aminobutyric acid (GABA) from wheat germinated in the presence of uncontrolled levels of dissolved oxygen was 18 +/- 3 times greater than that from nonsupplemented wheat (1 mg/100 g wheat).

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We studied the ability of different biomaterials to enantioselectively catalyze oxidation or reduction reactions with the help of substrate rac-1-m or p-ArCH(OH)Me and the 1-o-ArC(O)Me derivatives. Apoenzyme (NAD(P)(+)-dependent secondary alcohol dehydrogenase(NAD(P)-E)) and cofactor (NAD(P)(+)) were activated by preincubating immobilized aqueous plant leaf (e.g.

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We confirmed that an NAD(P)+-dependent secondary alcohol dehydrogenase (NAD(P)-E) can be easily and effectively isolated from pea, soybean, and wheat proteins immobilized with calcium alginate gel (IPP, ISP, and IWP, respectively). The estimated molecular mass of NAD(P)-E is 138.7 kDa, and the concentrations of NAD(P)-E in solution are 36.

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