Masakatsu Furui

n-acylation of β-amino alcohol by acyl migration following enzyme-catalyzed esterification

Abstract Lipase-catalyzed n -acylations of β-amino alcohols such as ethanolamine and l -serine were investigated. To prepare n -acyl derivatives by taking advantage of the acyl migration, we first carried out a screening of suitable enzymes for the desired reaction. As a result, we found a higher activity for n -acylation with Lipase Q L. This lipase had higher hydrolytic activity for the o-acyl compound but not the n -acyl compound. The observation shows that n -acylation results from the esterification and successive acyl migration into the amino group. Using Lipase Q L, we then investigated the n -acylation of ethanolamine or l -serine with fatty acids as acyl donors. The reaction parameters for the n -acylation were clarified.

D-Methionine preparation from racemic methionines by Proteus vulgaris IAM 12003 with asymmetric degrading activity

Abstract The microbial degradation of l-methionine was investigated in order to develop a practical process for d-methionine production from racemic methionines. Among the 1000 culture strains tested, microorganisms belonging to the Achromobacter, Bacillus, Micrococcus, Morganella, Proteus, Providencia, Pseudomonas and Sarcina genera exhibited a high l-methionine-degrading activity. Proteus vulgaris IAM 12003 was determined to be the best strain and was used as a biocatalyst for eliminating the l-isomer. The degradation of l-isomer in this P. vulgaris IAM 12003 cell was assured by the action of l-amino acid oxidase. The maximum rate of l-isomer degradation was obtained at 30u2009°C and pH 8.0. Under these optimal conditions, the l-isomer in a 100 g/l mixture of racemic methionines was almost degraded within 20 h, with 46.5 g d-methionine/l remaining in the reaction mixture. Crystalline d-methionine, with a chemical purity greater than 99% and optical purity of 99.9% enantiomeric excess, was obtained at a yield of 30% from the reaction mixture by simple purification.

A membrane bioreactor combined with crystallizer for production of optically active (2R, 3S)-3-(4-methoxyphenyl)-glycidic acid methyl ester

Abstract The combination of a membrane bioreactor using lipase from Serratia marcescens and a crystallizer has been proposed for the production of optically active ( 2R, 3S )-3-(4-methoxyphenyl) glycidic acid methyl ester ((−)MPGM) from racemic compounds ((±)MPGM). The reaction kinetics were investigated with a view toward industrial application of this newly devised bioreactor system. The following results were obtained. (i) The hydrolysis of (±)MPGM in the bioreactor system proceeded as a first-order reaction with respect to the substrate amount. (ii) The reaction rate depended on the amount of enzyme loaded onto a membrane module and the initial amount of substrate in the crystallizer. (iii) The reaction rate was not influenced by the rate of substrate circulation between the crystallizer and membrane bioreactor. (iv) Although the level of performance of the bioreactor system with respect to hydrolysis decreased with increasing operation time, it recovered to upon loading of fresh enzyme onto the membrane. This bioreactor system in which an enzymatic reaction and product crystallization occurred simultaneously had a high level of productivity compared with that of the conventional membrane bioreactor using a solubilized (±)MPGM substrate.

Scale-up of D-lysine production from L-lysine by successive chemical racemization and microbial asymmetric degradation

In order to develop an industrial production process of D-lysine from L-lysine, successive chemical racemization and a microbial asymmetric degradation were investigated in a pilot scale. The racemization of L-lysine proceeded quantitatively. The cultivation conditions of Comamonas testosteroni for L-lysine degradation were optimized in a 30L jar fermenter and scaled-up to 5m tank. The L-lysine-degrading reaction was performed by using racemized lysine crystals as substrate and C. testosteroni IAM 1048 intact cells as biocatalysts. Crystalline D-lysine, with a chemical purity greater than 99% and optical purity of 99.9% enantiomeric excess, was obtained at a yield of 36% from the reaction mixture by simple purification. On the basis of these results, we have designed a process for a large scale production of D-lysine.

Resolution of N-acetyl-DL-methionine methyl ester by protease-catalyzed hydrolysis with mild base as the pH control reagent

The following results were obtained: (1) A commercial protease preparation gave the best enantioselective hydrolysis of N-acetyl-dl-methionine methyl ester (N-Ac-dl-MetOMe) to produce N-Ac-l-Met with >99% e.e. (2)xa0Solid NaHCO3 prevented chemical hydrolysis of N-Ac-dl-MetOMe. (3)xa0N-Ac-l-Met was produced more efficiently when the pH was maintained at 7 with a mild base. (4)xa0Crystalline N-Ac-l-Met and d-Met were simultaneously obtained with >99% e.e. in 45 and 36% yield, respectively, from the reaction mixture.

Production of (2R,3S)-3-(4-methoxyphenyl)glycidic acid methyl ester using an emulsion bioreactor containing lipase fromSerratia marcescens

An emulsion bioreactor for production of (2R,3S)-3-(4-methoxyphenyl) glycidic acid methyl ester ([-]MPGM) from a racemic mixture ([±]MPGM) using the lipase fromSerratia marcescens has been proposed. Kinetics of hydrolyzing reaction and purification of (-)MPGM from the reaction mixture were investigated to provide a basis for industrial application of this bioreactor. The hydrolyzing reaction in the bioreactor proceeded at a rate that was first order in substrate concentration. The reaction rate was affected by a stirring speed and the ratio of the aqueous phase containing lipase to the toluene phase containing substrate. Phase separation after the enzymatic reaction was accomplished by addition of surfactant to the reaction mixture, and crystalline (-)MPGM with a chemical purity of 100% and optical purity of 100% enantiomeric excess was obtained in a high yield of 40–43% by concentration of the toluene solution.