Design of resolving reagents: p-substituted mandelic acids as resolving reagents for 1-arylalkylamines

Kinbara, Kazushi; Sakai, Kenichi; Hashimoto, Yukihiko; Nohira, Hiroyuki; Saigo, Kazuhiko

doi:10.1016/0957-4166(96)00175-9

Cited by 60 publications

(40 citation statements)

References 8 publications

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“…[2][3][4][5] (R)-(À)-Mandelic acid is a key intermediate for the production of semi-synthetic cephalosporins [6] and penicillins. [7] It is also used as a chiral resolving agent [8][9][10] and chiral synthon for the production of antitumor agents [11][12][13][14][15] and antiobesity agents. [16] It has been repeatedly reported that nitrilases are rather sensitive enzymes.…”

Section: Introductionmentioning

confidence: 99%

Cross‐Linked Amorphous Nitrilase Aggregates for Enantioselective Nitrile Hydrolysis

2007

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A recombinant Escherichia coli strain was constructed which efficiently expressed the enantioselective nitrilase from Alcaligenes faecalis DSMZ 30030 as a hisitidine-tagged enzyme variant under the control of a rhamnose inducible promoter. The enzyme was purified from cell extracts and used for the preparation of cross-linked enzyme aggregates (CLEAs). The conditions for the preparation of the CLEAs were optimized using various organic solvents and cross-linking agents and a procedure was developed which combined a precipitation with 85 % (v/v) isopropyl alcohol and a cross-linking with 30 mM glutaraldehyde. Thus, about 80 % of the initial nitrilase activity could be incorporated into the CLEAs. The hydrolysis of racemic mandelonitrile to (R)-mandelic acid was compared between the soluble nitrilase preparations and their CLEAs (nitCLEAs). The nitrilase activity in the CLEAs was at 30 8C and 608C about 5 times more stable than in the soluble preparations. The CLEAs could be reused 5 times with only about 10 % reduction in activity. The enantioselectivity of the nitrilase for the formation of (R)-mandelic acid from racemic mandelonitrile decreased for both preparations with increasing temperatures (10 8C to 508C), but this effect was significantly less pronounced for the CLEAs. A detailed analysis of solvent effects on nitrilase enantioselectivity allowed thermodynamic insights into contributions from free energy component (activation enthalpy and entropy) to chiral preference of nitrilase in such non conventional media.

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Section: Introductionmentioning

confidence: 99%

Cross‐Linked Amorphous Nitrilase Aggregates for Enantioselective Nitrile Hydrolysis

2007

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“…One study by Kinbara et al (1996) suggests that resolving agents comparable in molecular size and shape to the solute would result in a greater recovery of the desired enantiomer or its salt.…”

Section: February 2001mentioning

confidence: 98%

“…Consider multiple applications of a mixture of enantiomers as resolving agents if one of the enantiomers is not readily available but the mixture is (Ingersoll, 1925). Consider using a resolving agent in similar molecular shape and size to the solute (Kinbara et al, 1996).…”

Section: Table 3 Heuristics For Decision-making At Various Steps Of mentioning

confidence: 99%

Synthesis of chiral crystallization processes

Schroer

Wibowo

2001

AIChE Journal

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“…15 (R)-Mandelic acid, the most important representative of alpha-hydroxy acids, is not only an essential building block for drugs such as semi-synthetic penicillins, 16 cephalosporins, 17 antitumor 18 and anti-obesity agents, 19 but also a versatile resolving agent in chiral resolution processes. 20 Recently, various biological routes to optically active alpha-hydroxy acids have been reviewed. 21 Among these routes, biocatalytic reduction of prochiral ketones is a simple and promising one to manufacture chiral alcohols.…”

Section: Introductionmentioning

confidence: 99%

A highly stable whole‐cell biocatalyst for the enantioselective synthesis of optically active alpha‐hydroxy acids

Guo

Zheng

et al. 2009

J of Chemical Tech & Biotech

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BACKGROUND: Biocatalysts have gained increasing attention because of their inherent advantages over chemical catalysts. However, the poor operational stability has always prevented their broad application. In this study, (R)-mandelic acid was chosen as a model compound of alpha-hydroxy acids. The objective was to obtain a new biocatalyst with desired operational stability for the preparation of (R)-mandelic acid as well as other optically pure alpha-hydroxy acids of pharmaceutical importance.

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Design of resolving reagents: p-substituted mandelic acids as resolving reagents for 1-arylalkylamines

Cited by 60 publications

References 8 publications

Cross‐Linked Amorphous Nitrilase Aggregates for Enantioselective Nitrile Hydrolysis

Cross‐Linked Amorphous Nitrilase Aggregates for Enantioselective Nitrile Hydrolysis

Synthesis of chiral crystallization processes

A highly stable whole‐cell biocatalyst for the enantioselective synthesis of optically active alpha‐hydroxy acids

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