Asymmetric Synthesis of an (<i>R</i>)-Cyanohydrin Using Enzymes Entrapped in Lens-Shaped Gels

Gröger, Harald; Capan, Emine; Barthuber, and Anita; Vorlop, Klaus‐Dieter

doi:10.1021/ol015920g

Cited by 57 publications

(42 citation statements)

References 17 publications

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“…[51] As noted above, in order to retain the enzyme in a PVA hydro- gel, in the presence of water, the molecular weight must be increased. Grçger and co-workers [52] achieved this by cross-linking an (R)-oxynitrilase using a mixture of glutaraldehyde and chitosan ( Figure 4). The cross-linked enzyme was subsequently entrapped in a Lentikat PVA hydrogel.…”

Section: Hydrogelsmentioning

confidence: 99%

Enzyme Immobilization: The Quest for Optimum Performance

2007

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Immobilization is often the key to optimizing the operational performance of an enzyme in industrial processes, particularly for use in non-aqueous media. Different methods for the immobilization of enzymes are critically reviewed. The methods are divided into three main categories, viz. (i) binding to a prefabricated support (carrier), (ii) entrapment in organic or inorganic polymer matrices, and (iii) cross-linking of enzyme molecules. Emphasis is placed on relatively recent developments, such as the use of novel supports, e.g., mesoporous silicas, hydrogels, and smart polymers, novel entrapment methods and cross-linked enzyme aggregates (CLEAs).

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Section: Hydrogelsmentioning

confidence: 99%

Enzyme Immobilization: The Quest for Optimum Performance

2007

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“…[188][189][190] Free (R)-oxynitrilases suffer from rapid deactivation, low substrate loading and poor recyclability. 188,190 As is evident from Table 7 by modifying the enzyme through cross-linking and entrapping ( Figure 8) 191 an improved result was obtained, regarding efficiency as well as yield and enantioselectivity. The desired (R)-mandelonitrile 11 was obtained with 94% e.e.…”

Section: Practical Applications Of Cross-linked Enzyme Aggregatesmentioning

confidence: 95%

“…This might be due to an increased stabilisation of the enzyme within the hydrogel matrix. [190][191] A further example of the synthetic utility of CLEAs is demonstrated by Cao et al 192 Penicillin G acylase is widely used in the industrial synthesis of Ampicillin 12. All viable syntheses involve an activated side-chain donor such as D-phenylglycine amide 13 which acylates 6-APA 14 in the presence of penicillin acylase in a kinetically controlled reaction; water is the reaction medium of choice.…”

Section: Practical Applications Of Cross-linked Enzyme Aggregatesmentioning

confidence: 99%

Recent trends in whole cell and isolated enzymes in enantioselective synthesis

Milner¹,

Maguire²

2012

Arkivoc

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Modern synthetic organic chemistry has experienced an enormous growth in biocatalytic methodologies; enzymatic transformations and whole cell bioconversions have become generally accepted synthetic tools for asymmetric synthesis. This review details an overview of the latest achievements in biocatalytic methodologies for the synthesis of enantiopure compounds with a particular focus on chemoenzymatic synthesis in non-aqueous media, immobilisation technology and dynamic kinetic resolution. Furthermore, recent advances in ketoreductase technology and their applications are also presented.Keywords: Biocatalysis, kinetic and dynamic kinetic resolution, Baker's yeast, ketoreductases General IntroductionAsymmetric synthesis is the preferential formation of one stereoisomer of a chiral target compound to another; when scientists at GlaxoSmithKline, AstraZeneca and Pfizer 1 examined 128 syntheses from their companies, they found as many as half of the drug compounds made by their process research and development groups are not only chiral but also contain an average of two chiral centres each. 2In 2006 just 25 % were derived from the chiral pool and over 50 % employed chiral technologies. 1In order to meet regulatory requirements enantiomeric purities of 99.5 % were deemed necessary by the FDA. 3 This is one of the biggest challenges which face chemists today, primarily due to the recognition of the fact that different enantiomers of the same compound can interact differently in biological systems. As a consequence, the production of single enantiomers instead of racemic mixtures has become an important process in the pharmaceutical and agrochemical industry. Several routes can lead to the desired enantiomer including transition metal-, [4][5][6] organo-5,7-10 and bio-catalysis [11][12][13][14][15] and these have been thoroughly reviewed in the literature. 16,17 2. Biocatalysis IntroductionBiocatalysis involves the use of enzymes or whole cells (containing the desired enzyme or enzyme system) as catalysts for chemical reactions. A timeline of historic events in biocatalysis and biotechnology is outlined in Table 1. [18][19][20] Reviews and Accounts Novel methodologies for discovering industrial enzymes based on genomic sequencing and phage display (discussed further in Section 1.3), 21,22 as well as highly effective optimisation tools based on chemical, physical and molecular biology approaches, 23 have improved the access to biocatalysts, increased their stability, and radically broadened their specificity. 24This greater availability of catalysts with superior qualities including the use of new bioengineering tools contributed significantly to the development of new industrial processes. Biocatalytic methodologies for organic synthesis were outlined by Woodley et al. in three categories: established, emerging and expanding chemistries as depicted in Figure 1. 25 Enzyme classesBy the late 1950s it had become evident that the nomenclature of enzymes without any guiding authority, in a period when the...

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“…Almonds provide a rich source of this enzy me [2,[19][20][21][22][23]. Thus, for examp le, co mpound (R)-2b was obtained with enantio meric excess value (ee %) of 91 % ( 1 H NM R) and a specific rotation value [α] D/25 of + 38.4 (c 0.01666, acetone).…”

Section: Chemistry Synthesis Of the Optically Active Cyanohydrins 2a-dmentioning

confidence: 99%

“…Besides, it can be enzymatically cataly zed by means of hydro xynitrile lyases (o xynitrilases) extracted fro m plant sources [2,4,19]. This approach is rather decisive, clean and cheap [5,[20][21][22][23]. The increasing interest in synthesizing optically pure compounds is due to the well established correlation between the biological act ivity and stereochemical aspects [24][25][26][27].…”

mentioning

confidence: 99%

Preparation and Reactions of Certain Racemic and Optically Active Cyanohydrins Derived from 2-Chlorobenzaldehyde, 4-Fluorobenzaldehyde, Benzo[d][1,3]-dioxole-5-carbaldehyde and 2,3-Dihydrobenzo[b][1,4]dioxine-6-carbaldehyde. Antimicrobial and in vitro Antitumor Evaluation of the Products

2017

Egypt. J. Chem.

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Asymmetric Synthesis of an (R)-Cyanohydrin Using Enzymes Entrapped in Lens-Shaped Gels

Cited by 57 publications

References 17 publications

Enzyme Immobilization: The Quest for Optimum Performance

Enzyme Immobilization: The Quest for Optimum Performance

Recent trends in whole cell and isolated enzymes in enantioselective synthesis

Preparation and Reactions of Certain Racemic and Optically Active Cyanohydrins Derived from 2-Chlorobenzaldehyde, 4-Fluorobenzaldehyde, Benzo[d][1,3]-dioxole-5-carbaldehyde and 2,3-Dihydrobenzo[b][1,4]dioxine-6-carbaldehyde. Antimicrobial and in vitro Antitumor Evaluation of the Products

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