Biocatalysis in organic solvents

Natarajan, K. R.

doi:10.1021/ed068p13

Cited by 23 publications

(4 citation statements)

References 22 publications

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“…The hydrophilicity is directly proportional to the dielectric constant ɛ and the donor/acceptor characteristics of the solvent. In some cases, the water-protein interactions are so tight that hydrophilic solvents have difficulties in striping water away [ 31 ]. MeOH and EtOH ( ɛ = 33 and 30) are able to accept and to donate hydrogen bonds to water.…”

Section: Resultsmentioning

confidence: 99%

First Insights on Organic Cosolvent Effects on FhuA Wildtype and FhuA Δ1-159

Tenne

Schwaneberg

2012

IJMS

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Circular dichroism (CD) and deconvolution were used to study the structural integrity of a “plugged” and an “open” FhuA transmembrane channel protein in the presence of varied concentrations of tetrahydrofuran (THF), ethanol (EtOH) and chloroform/methanol (C/M). FhuA is an Escherichia coli outer membrane protein (78.9 kDa) consisting of 22 β-sheets and an internal globular cork domain which acts as an iron transporter. FhuA and the deletion variant FhuA Δ1-159 showed comparable and remarkable resistance in the presence of THF (≤40 vol%) and EtOH (≤10 vol%). In C/M, significant differences in structural resistance were observed (FhuA stable ≤10 vol%; FhuA Δ1-159 ≤1 vol%). Deconvolution of CD-spectra for FhuA and FhuA Δ1-159 yielded β-sheet contents of 61 % (FhuA) and 58% (FhuA Δ1-159). Interestingly, FhuA and FhuA Δ1-159 had comparable β-sheet contents in the presence and absence of all three organic cosolvents. Additionally, precipitated FhuA and FhuA Δ1-159 (in 40 vol% C/M or 65 vol% THF) redissolved by supplementing the detergent n-octyl-oligo-oxyethylene (oPOE).

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Section: Resultsmentioning

confidence: 99%

First Insights on Organic Cosolvent Effects on FhuA Wildtype and FhuA Δ1-159

Tenne

Schwaneberg

2012

IJMS

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“…However, with the rise of biocatalysis in the 1980s, and the necessity to explore the versatility of the application of enzymes in different industrial processes, the initiative to use enzymes in non‐conventional (non‐aqueous) media arose, and proved to be successful [1,2] . Advantages of the use of water‐free media in biocatalysis are the greater stability of enzymes, and the straightforward recovery of the catalyst [3] . In particular, the advantages of using water as a reaction medium are easily outweighed in the case of industrial processes, where enzymes typically catalyze non‐natural organic substrates which have a higher solubility in non‐aqueous media [4] .…”

Section: Introductionmentioning

confidence: 99%

“…[1,2] Advantages of the use of water-free media in biocatalysis are the greater stability of enzymes, and the straightforward recovery of the catalyst. [3] In particular, the advantages of using water as a reaction medium are easily outweighed in the case of industrial processes, where enzymes typically catalyze nonnatural organic substrates which have a higher solubility in non-aqueous media. [4] Although a minimum amount of water is necessary for the hydration of the enzyme molecule, this is relatively low and no bulk quantities of water are needed.…”

Section: Introductionmentioning

confidence: 99%

Enzymatic Cascade for the Synthesis of 2,5‐Furandicarboxylic Acid in Biphasic and Microaqueous Conditions: ‘Media‐Agnostic’ Biocatalysts for Biorefineries

Milić

Byström²,

Marı́a³

et al. 2022

ChemSusChem

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5‐hydroxymethylfurfural (HMF) is produced upon dehydration of C6 sugars in biorefineries. As the product, it remains either in aqueous solutions, or is in situ extracted to an organic medium (biphasic system). For the subsequent oxidation of HMF to 2,5‐furandicarboxylic acid (FDCA), ‘media‐agnostic’ catalysts that can be efficiently used in different conditions, from aqueous to biphasic, and to organic (microaqueous) media, are of interest. Here, the concept of a one‐pot biocatalytic cascade for production of FDCA from HMF was reported, using galactose oxidase (GalOx) for the formation of 2,5‐diformylfuran (DFF), followed by the lipase‐mediated peracid oxidation of DFF to FDCA. GalOx maintained its catalytic activity upon exposure to a range of organic solvents with only 1 % (v/v) of water. The oxidation of HMF to 2,5‐diformylfuran (DFF) was successfully established in ethyl acetate‐based biphasic or microaqueous systems. To validate the concept, the reaction was conducted at 5 % (v/v) water, and integrated in a cascade where DFF was subsequently oxidized to FDCA in a reaction catalyzed by Candida antarctica lipase B.

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“…A imobilização de enzimas é uma das técnicas mais importantes na aplicação de catálise enzimática para reações sintéticas em solventes orgânicos [5][6][7][8][9][10] . Por razões prática e econômica, é muitas vezes vantajoso usar enzimas imobilizadas visto que, com poucas exceções, elas são insolú-veis em solventes orgânicos 11 .…”

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Organo-gel: um novo sistema para a imobilização de lipases e sua aplicação em síntese orgânica

et al. 1997

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o C. This methodology is described as a new alternative for the use of enzymes in organic solvents. High enzymic stability has been observed. We have also used this methodology for the successful resolution of chiral secondary alcohols. This is a convenient way of using this catalyst in organic solvents which employs small amounts of the enzyme (250µg/mL).Keywords: lipases; immobilization; organogels. DIVULGAÇÃO INTRODUÇÃOA habilidade das enzimas para atuarem como catalisadores já tem sido considerada por muitos anos, particularmente pela indústria farmacêutica [1][2][3][4] . A imobilização de enzimas é uma das técnicas mais importantes na aplicação de catálise enzimática para reações sintéticas em solventes orgânicos [5][6][7][8][9][10] . Por razões prática e econômica, é muitas vezes vantajoso usar enzimas imobilizadas visto que, com poucas exceções, elas são insolú-veis em solventes orgânicos 11 . Uma das grandes vantagens da imobilização é poder utilizar o catalisador repetidamente sem considerável perda da atividade catalítica 12 . Considerando a compatibilidade com a enzima, géis hidrofílicos têm sido frequentemente empregados como suportes enzimáticos. Às vezes, a enantiosseletividade é aumentada 12 . Alguns sistemas que já foram usados para imobilizar enzimas são Eupergit C 13 , celite 11,14,15 , quitosana e quitina 11 , agarose, Chromosorb e Sepharose 13,16,17 . A modificação de enzimas com polietilenoglicol que resulta em um pó solúvel em benzeno ou em hidrocarbonetos clorados, também tem sido empregada [18][19][20][21][22] . Outras técnicas que superam os problemas da baixa solubilidade dos substratos, são o uso de surfactantes e micelas reversas [23][24][25][26][27][28][29][30][31][32][33][34][35][36] . Na última década, muitos estudos têm se voltado para a utilização de microemulsões para imobilização de enzimas [37][38][39][40][41][42][43][44] . Uma microemulsão é uma dispersão isotrópica e opticamente transparente de óleo em água (O/W) ou de água em óleo (W/O), onde o óleo é um solvente orgânico (hexano, heptano). O nome "microemulsão" deriva do fato de que gotas de óleo no sistema (O/W), ou gotas de água no sistema (W/O), possuem um diâmetro que varia de 50 a 500 Å 45,46 . Como as microemulsões são sistemas organizados, elas são fáceis de serem preparadas. A estabilidade da microemulsão depende da razão da concentração de água pelo surfactante adicionado ao meio, representado por W 0 , onde:A gota de microemulsão pode ser efetivamente considerada como um microreator. Robinson e col., estudando as propriedades das microemulsões, concluiram que a sua estabilidade depende da concentração de óleo, água e surfactante presentes no meio 43 . Haering, Luise 42 , Quellet e col. [47][48][49][50][51] descreveram o efeito da solubilização de gelatina em uma microemulsão água / óleo (W/O) na formação do gel. Este é obtido pelo resfriamento de uma solução previamente aquecida a 55°C de Aerosol-OT (sulfosuccinato sódico de bis-2-etilhexila) em solvente orgâni-co (hexano, heptano) e uma solução aquosa de gelatin...

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Biocatalysis in organic solvents

Abstract: This article highlights why it is sometimes desirable to select organic solvents when carrying out enzymatic reactions, criteria for solvent selection, effects of organic solvents on enzymes, applications, and future prospects.

Cited by 23 publications

References 22 publications

First Insights on Organic Cosolvent Effects on FhuA Wildtype and FhuA Δ1-159

First Insights on Organic Cosolvent Effects on FhuA Wildtype and FhuA Δ1-159

Enzymatic Cascade for the Synthesis of 2,5‐Furandicarboxylic Acid in Biphasic and Microaqueous Conditions: ‘Media‐Agnostic’ Biocatalysts for Biorefineries

Organo-gel: um novo sistema para a imobilização de lipases e sua aplicação em síntese orgânica

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