Improving the enantioselective bioreduction of aromatic ketones mediated by Aspergillus terreus and Rhizopus oryzae: the role of glycerol as a co-solvent

Andrade, Leandro H.; Piovan, Leandro; Pasquini, Mônica D`Arcadia

doi:10.1016/j.tetasy.2009.05.033

Cited by 30 publications

(19 citation statements)

References 33 publications

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“…Thus, in the enantioselective bioreduction of 2 0 -chloroacetophenone by cells of Aspergillus terreus in phosphate buffer solution (pH 7), they observed remarkable yield and enantioselectivity improvements by adding variable amounts of glycerol (entries 2 and 3 vs. 1 in Table 4). 95 As shown in Table 4, such improvements were in general not observed using other water-organic solvent mixtures (entries 4-13). Three factors have been evoked to explain the beneficial effect of glycerol in this reaction: (i) it improves the solubility of the substrate, (ii) unlike the other organic solvents, it generates a homogeneous medium in combination with water that avoids mass transfer limitations facilitating the enzyme-substrate interactions, and (iii) it stabilizes the protein native structure and prevents its denaturation, thus preserving the enzymatic activity.…”

Section: Biocatalysismentioning

confidence: 93%

Glycerol and derived solvents: new sustainable reaction media for organic synthesis

et al. 2011

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The rapid growth of the biodiesel industry has led to a large surplus of its major byproduct, i.e. glycerol, for which new applications need to be found. Research efforts in this area have focused mainly on the development of processes for converting glycerol into value-added chemicals and its reforming for hydrogen production, but recently, in line with the increasing interest in the use of alternative greener solvents, an innovative way to revalorize glycerol and some of its derivatives has seen the light, i.e. their use as environmentally friendly reaction media for synthetic organic chemistry. The aim of the present Feature Article is to provide a comprehensive overview on the developments reached in this field.

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Section: Biocatalysismentioning

confidence: 93%

Glycerol and derived solvents: new sustainable reaction media for organic synthesis

et al. 2011

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“…Hara et al 41 When the solvent mixture of n-hexane/glycerol (9:1 v:v) was used, the degree of conversion to the (R)-3 ester was 42 also observed an improvement in the enzymatic performance of Aspergillus terreus and Rhizopus oryzae in the enantioselective bioreduction of haloacetophenones using glycerol as a co-solvent. In most cases, glycerol has demonstrated its potential to improve the conversion (up to > 99%) and enantioselectivity (up to > 99%) when compared to reactions in aqueous or other aqueous-organic media (THF, diethyl ether, toluene, DMSO and acetonitrile).…”

Section: Effect Of Organic Solventmentioning

confidence: 98%

“…Moreover, the choice of this co-solvent is reinforced by its increasing availability on the market, since it is a by-product of biodiesel production. 42 …”

Section: Effect Of Organic Solventmentioning

confidence: 99%

Enantioselective resolution of (R,S)-1-phenylethanol catalyzed by lipases immobilized in starch films

Hoffmann¹,

Silva²,

Nascimento³

2011

J. Braz. Chem. Soc.

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Lipases de diferentes fontes e dois micélios, na forma livre ou imobilizados em filme de amido de gengibre, foram utilizados como catalisadores na reação do (R,S)-1-feniletanol (1) com acetato de vinila e outros agentes acilantes. Os efeitos de vários parâmetros na resolução de (1) catalisada pela lipase de Burkholderia cepacia (LBC) imobilizada em filme de amido de gengibre (tipo do doador acila, razão molar álcool:doador acila, temperatura e solvente orgânico) foram avaliados. A eficiência catalítica da LBC imobilizada em blendas de amido de gengibre e poli (oxido de etileno) (PEO), em diferentes composições, também foi estudada. Os acetato de vinila e o de iso-propenila forneceram as maiores conversões (9%) e excessos enantioméricos em (R)-éster (> 99%). A razão molar álcool:doador acila e temperatura ótima foram de 1:1 e 28 °C, respectivamente. A mistura de n-hexano/glicerol (9:1 v:v) foi a mais adequada para esta reação (conversão 23%, E > 200). A blenda de amido de gengibre/PEO (7:3 m/m) foi reutilizada por seis vezes consecutivas.Lipases from different sources and two mycelium-bound lipases, in a free or immobilized form, in ginger starch film were screened as biocatalysts in the reaction of (R,S)-1-phenylethanol (1) with vinyl acetate and other acylating agents. The effect of various reaction parameters in the resolution of (1) catalyzed by lipase from Burkholderia cepacia (BCL) immobilized in ginger starch film was evaluated (acyl donor type, alcohol:acyl donor molar ratio, temperature and organic solvent). The catalytic efficiency of BCL immobilized in polymeric blends of ginger starch and polyethylene oxide (PEO), in different compositions, was also studied. Vinyl acetate and iso-propenyl acetate furnished the highest conversion (9%) and enantiomeric excess (> 99%) of the (R)-ester. The alcohol:acyl donor molar ratio and temperature optimum were 1:1 and 28 °C, respectively. The mixture of n-hexane/glycerol (9:1 v:v) was the most adequate for this reaction (conversion 23%, E > 200). The ginger starch/PEO (7:3 m/m) blend was successfully reused six times consecutively. Keywords: starch film, immobilization, lipases, enzymatic resolution IntroductionIn recent years, the application of enzymes and microorganisms as biocatalysts in organic synthesis has become a well-known technique.1,2 Enzymatic procedures to obtain a wide range of products under mild and environmentaly-friendly conditions have become attractive and promising due to the excellent stereoselectivity of enzymes.3 Lipases (triacylglycerol hydrolases EC 3.1.1.3) are the most widely applied enzymes for regio-, chemoand enantioselective biotransformations, because they also possess wide substrate specificity, have an excellent ability to recognize chirality, and do not require cofactors.1,4 They have found wide usage in a growing range of industrial applications, such as in detergents, food processing, biotransformations, waste treatment and bioremediation. They have been used by the pharmaceutical, cosmetics, textile, leather and paper industri...

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“…However, except for very few examples (Baratta et al, 2008;Evans et al, 2003;Zeror et al, 2008), use of these catalysts was prohibited by insufficient enantioselectiviy. Several microbial and plant cells inheriting o-chloroacetophenone reductase activity have been identified by extensive screening recently (Andrade et al, 2005(Andrade et al, , 2009Kagohara et al, 2008;Kurbanoglu et al, 2007aKurbanoglu et al, ,b, 2010Nakamura and Matsuda, 1998;Ou et al, 2008;Salvi and Chattopadhyay, 2008;Xie et al, 2006). However, the number of isolated and characterized enzymes (Gröger et al, 2006;Itoh et al, 1999;Yang et al, 2007;Zhu et al, 2006) exhibiting o-chloroacetophenone reductase activity is still limited.…”

Section: Introductionmentioning

confidence: 99%

Enzyme identification and development of a whole‐cell biotransformation for asymmetric reduction ofo‐chloroacetophenone

Kratzer

Pukl

Egger

et al. 2010

Biotech & Bioengineering

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Chiral 1-(o-chlorophenyl)-ethanols are key intermediates in the synthesis of chemotherapeutic substances. Enantioselective reduction of o-chloroacetophenone is a preferred method of production but well investigated chemo- and biocatalysts for this transformation are currently lacking. Based on the discovery that Candida tenuis xylose reductase converts o-chloroacetophenone with useful specificity (kcat/Km=340 M(-1) s(-1)) and perfect S-stereoselectivity, we developed whole-cell catalysts from Escherichia coli and Saccharomyces cerevisiae co-expressing recombinant reductase and a suitable system for recycling of NADH. E. coli surpassed S. cerevisiae sixfold concerning catalytic productivity (3 mmol/g dry cells/h) and total turnover number (1.5 mmol substrate/g dry cells). o-Chloroacetophenone was unexpectedly "toxic," and catalyst half-life times of only 20 min (E. coli) and 30 min (S. cerevisiae) in the presence of 100 mM substrate restricted the time of batch processing to maximally ∼5 h. Systematic reaction optimization was used to enhance the product yield (≤60%) of E. coli catalyzed conversion of 100 mM o-chloroacetophenone which was clearly limited by catalyst instability. Supplementation of external NAD+ (0.5 mM) to cells permeabilized with polymyxin B sulfate (0.14 mM) resulted in complete conversion providing 98 mM S-1-(o-chlorophenyl)-ethanol. The strategies considered for optimization of reduction rate should be generally useful, however, especially under process conditions that promote fast loss of catalyst activity.

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Improving the enantioselective bioreduction of aromatic ketones mediated by Aspergillus terreus and Rhizopus oryzae: the role of glycerol as a co-solvent

Cited by 30 publications

References 33 publications

Glycerol and derived solvents: new sustainable reaction media for organic synthesis

Glycerol and derived solvents: new sustainable reaction media for organic synthesis

Enantioselective resolution of (R,S)-1-phenylethanol catalyzed by lipases immobilized in starch films

Enzyme identification and development of a whole‐cell biotransformation for asymmetric reduction ofo‐chloroacetophenone

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