- Solvent Configuration influences Enzyme Activity in Organic Media
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The activities of three hydrolases and one oxidoreductase have been found to be different when using (R)-carvone or (S)-carvone as the reaction medium indicating that solvent geometry can influence enzyme catalysis.
- Ottolina, Gianluca,Gianinetti, Francesca,Riva, Sergio,Carrea, Giacomo
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- Immobilization of a lipase on mesocellular foam of silica for biocatalysis in low-water-containing organic solvents
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Unfunctionalized mesocellular foam of silica was used for immobilization of the lipase from Thermomyces lanuginosus. In the first approach, lipase was adsorbed onto polyethyleneiminecoated Fe3O4 nanoparticles, and these particles in
- Kannan, Kayambu,Mukherjee, Joyeeta,Gupta, Munishwar N.
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- A chemically modified lipase preparation for catalyzing the transesterification reaction in even highly polar organic solvents
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Acylation of Pseudomonas cepacia lipase with Pyromellitic dianhydride to modify 72% of total amino groups was carried out. Different organic solvents were screened for precipitation of modified lipase. It was found that 1,2-dimethoxyethane was the best pr
- Solanki, Kusum,Gupta, Munishwar Nath
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- Lipase-Catalysed Acylation of Alcohols by Fatty Acid Anhydrides. Evaluation of the Selectivity Based on Kinetic Measurements.
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A method based on the analysis of kinetic measurements is described for evaluating the enantioselectivity of the lipase-catalysed acylation of alcohols by fatty acid anhydrides in cases where enantiomer separation is not feasible.
- Fourneron, Jean-Dominique,Combemorel, Alain,Buc, Jean,Pieroni, Gerard
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- Enzyme Access Tunnel Engineering in Baeyer-Villiger Monooxygenases to Improve Oxidative Stability and Biocatalyst Performance
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Hydrogen peroxide is involved in a variety of enzyme catalysis as an oxidant or toxic by-product. Thereby, attenuation of the H2O2-driven oxidative stress is one of the key issues for preparative biocatalysis. Here, a rational approach to improve the robustness of enzymes, in particular, Baeyer-Villiger monooxygenases (BVMOs) against H2O2 was investigated. The enzyme access tunnels, which may serve as exit paths for H2O2 from the active site to the bulk, were predicted by using the CAVER and/or protein energy landscape exploration (PELE) software for the phenylacetone monooxygenase variant (PAMO_C65D) from Thermobifida fusca and the BVMO from Pseudomonas putida KT2440. The amino acid residues, which are susceptible to oxidation by H2O2 (e. g., methionine and tyrosine) and located in vicinity of the predicted H2O2 migration paths, were substituted with less reactive or inert amino acids (e. g., leucine and isoleucine). This led to design of the H2O2-resistant enzyme variants, which became robust biocatalysts for synthetic applications. For instance, the H2O2-resistant P. putida BVMO reached turnover numbers of 4,100 for the BV oxygenation of 4-decanone, which is 2.8-fold greater than the parent enzyme. Moreover, the H2O2-resistant P. putida BVMO allowed 2-fold enhancement in titer of 9-(nonanoyloxy)nonanoic acid (8) formation in a cascade fatty acid biotransformation. Therefore, it was assumed that the CAVER/PELE-based H2O2 migration path engineering represents an efficient rational design approach to improve not only oxidative stability but also biotransformation performance of the H2O2-forming or utilizing enzymes (e. g., BVMOs, oxidases, and peroxidases). (Figure presented.).
- Bornscheuer, Uwe,Kim, Myeong-Ju,Oh, Deok-Kun,Park, Jin-Byung,Park, Seongsoon,Park, So-Yeon,Seo, Eun-Ji
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supporting information
(2021/11/10)
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- Modulation of starch nanoparticle surface characteristics for the facile construction of recyclable Pickering interfacial enzymatic catalysis
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In this work, maize starch (MS) was successively modified via an esterification reaction with acetic anhydride (AA) and phthalic anhydride (PTA). Combined with the gelatinization-precipitation process, the formed starch nanoparticles at an AA/PTA ratio of 2 (MS-AP (2)) and 3 (MS-AP (3)) had similar regular spheres but distinct surface characteristics. In order to enhance the activity of lipase B from Candida antarctica (CALB) in an organic solvent, we designed an oil-in-water (o/w) and a water-in-oil (w/o) Pickering interfacial catalytic system simultaneously by utilizing MS-AP (2) and MS-AP (3) as robust Pickering emulsion stabilizers. Impressively, during the esterification of 1-butanol and vinyl acetate, the specific activity of CALB in the o/w (0.0843 U μL-1) or w/o (0.0724 U μL-1) Pickering interfacial catalytic system was much higher than that of free enzymes in the monophasic (0.0198 U μL-1) and biphasic (0.0282 U μL-1) system. Moreover, after preliminarily elaborating mass transfer discrepancies between the o/w and w/o Pickering interfacial catalytic systems and calculating their mass transfer resistance, we clarified the effects of the location of these two phases on the catalytic capacity of the Pickering emulsion. Impressively, both Pickering interfacial catalytic systems exhibited high effectiveness in product separation. It was found that the w/o Pickering emulsion enabled the organic product to be facilely isolated through a simple decantation, while the o/w Pickering emulsion achieved similar results after adjusting the system temperature. The bio-based nanomaterials and simple protocol, in conjunction with the stability to simultaneously achieve high catalysis efficiency and excellent recyclability, makes us believe that this starch nanoparticle-based Pickering interfacial catalytic system is a promising system for meeting the requirements of green and sustainable chemistry.
- Qi, Liang,Luo, Zhigang,Lu, Xuanxuan
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p. 2412 - 2427
(2019/05/17)
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- Efficient Enzymatic Preparation of Flavor Esters in Water
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A straightforward biocatalytic method for the enzymatic preparation of different flavor esters starting from primary alcohols (e.g., isoamyl, n-hexyl, geranyl, cinnamyl, 2-phenethyl, and benzyl alcohols) and naturally available ethyl esters (e.g., formate, acetate, propionate, and butyrate) was developed. The biotransformations are catalyzed by an acyltransferase from Mycobacterium smegmatis (MsAcT) and proceeded with excellent yields (80-97%) and short reaction times (30-120 min), even when high substrate concentrations (up to 0.5 M) were used. This enzymatic strategy represents an efficient alternative to the application of lipases in organic solvents and a significant improvement compared with already known methods in terms of reduced use of organic solvents, paving the way to sustainable and efficient preparation of natural flavoring agents.
- Perdomo, Igor Chiarelli,Gianolio, Stefania,Pinto, Andrea,Romano, Diego,Contente, Martina Letizia,Paradisi, Francesca,Molinari, Francesco
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p. 6517 - 6522
(2019/06/20)
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- Synthesis of butyrate using a heterogeneous catalyst based on polyvinylpolypyrrolidone
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A heterogeneous polyvinylpolypyrrolidone supported Br?nsted acidic catalyst ([PVPP-BS]HSO4) was used to synthesize butyrate in this paper. The prepared catalysts were characterized by FT-IR, TG, and FESEM and their catalytic activity in butyric acid esterification with benzyl alcohol was investigated. The influencing factors such as the amount of catalyst, reaction temperature, and reaction time were carefully studied. Under the optimized condition with the butyric acid to benzyl alcohol mole ratio of 1 : 1.2 and the reaction temperature of 130°C, the yield of benzyl butyrate reached 96.8 % within 4 h in the presence of 8 mass % of catalyst. Moreover, the catalyst could be reused six times without noticeable drop in activity. This catalyst was also used to synthesize other kinds of butyrates achieving the butyrate yield above 90 %.
- Wang, Song,Chang, Qian-Qian,Shawgi, Nazar,Li, San-Xi,Zhang, Lin-Nan
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p. 538 - 544
(2016/03/05)
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- Graphite oxide as an efficient solid reagent for esterification reactions
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Esterification of organic acids with alcohols under mild conditions in high yields using graphite oxide, a readily available and inexpensive material, as an effective reagent is described.
- Mirza-Aghayan, Maryam,Rahimifard, Mahshid,Boukherroub, Rabah
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p. 859 - 864
(2014/12/10)
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- Rapeseed lipase catalyzed synthesis of butyl butyrate for flavour and nutraceutical applications in organic media
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Butyl butyrate, a short chain ester with fine fruity pineapple odour, is a significant flavour compound. Recent investigations show that butyrate esters also have anticancer activity. Factors influencing the synthesis of butyl butyrate by organic phase biocatalysis were investigated. Maximum ester yield of 89% was obtained when 0.25 M butanol and butyric acid were reacted at 25 °C for 48 h in the presence of 250 mg rape seed lipase acetone powder in hexane. Addition of water did not affect synthesis, while a water activity of 0.45 was found optimum. Of 15 different alcohols evaluated, isoamyl and (Z)-3- hexen-1-ol were esterified most effectively with molar conversion yields of 92.2 and 80.2%. Short chain primary alcohols such as methanol and medium-long chain alcohols, such as heptanol and octanol were esterified more slowly. The results show that rape seed lipase is versatile catalyst for ester synthesis with temperature stability range 5-50 °C.
- Liaquat, Muhammad
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experimental part
p. 6 - 13
(2012/06/18)
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- Synthesis of short chain alkyl esters using cutinase from Burkholderia cepacia NRRL B2320
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Short chain alkyl esters are well appreciated for fruity flavors they provide. These are mainly applied to the fruit-flavored products like jam, jelly, beverages, wine and dairy. Cutinase from Burkholderia cepacia NRRL B 2320 was found to be active in catalyzing the synthesis of alkyl esters in organic solvent. The optimal temperature range for the enzyme catalyzed synthesis was found to be from 35 °C to 40 °C. The maximum conversion (%) during synthesis of ester was obtained for butyric acid (C4) and valeric acid (C5) with butanol reflecting the specificity of the enzyme for short-chain length fatty acids. In case of alcohol specificity, butanol was found to be most preferred substrate by the enzyme and conversion (%) decreased with increasing carbon chain length of alcohol used in the esterification reaction. The kinetic analysis for the synthesis of butyl butyrate by varying concentration of one substrate at a time (butanol or butyric acid), showed that Ping-Pong Bi Bi model with acid inhibition and influence of initial water is most suitable model for the prediction of the reaction kinetics.
- Dutta, Kasturi,Dasu, Veeranki Venkata
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experimental part
p. 150 - 156
(2012/07/01)
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- Structure-function correlation in lipase catalysed esterification reactions of short and medium carbon chain length alcohols and acids
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An attempt has been made to correlate the carbon chain lengths of acids and alcohols to the extent of esterification in the Rhizomucor miehei lipase catalyzed esterification reactions involving acids of carbon chain length C2-C5 and alcohols of carbon chain length C1-C8.
- Divakar, Soundar
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p. 1919 - 1922
(2007/10/03)
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- Synthesis of the sex pheromone of Lygus lineolaris (Heteroptera miridae)
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We propose a new synthesis of the sex pheromone of Lygus lineolaris (Heteroptera miridae) that uses a phase-transfer version of the Wittig - Horner reaction to produce a monoene synthon of the principal component of the pheromone, E-2-hexenylbutyrate.
- Shakirzyanova,Abdukakharov,Abduvakhabov
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p. 623 - 624
(2007/10/03)
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- THERMAL ESTERIFICATION OF CARBOXYLIC ACIDS WITH ALCOHOLS
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Catalyst-free esterification of carboxylic acids with alcohols has been studied, and the optimal process conditions have been determined.
- Magerramov, M. N.
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p. 291 - 293
(2007/10/03)
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- Rate enhancement of the Candida cylindracea lipase catalysed transesterification in organic solvents: Enzymatic reactions below zero
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The rate of transesterification reactions of primary and secondary alcohols, catalysed by the lipase from Candida cylindracea in organic solvents, can be accelerated when methoxyacyl is the transacylating group in the transacylating agent.This phenomenon allows efficient transesterifications to be catalysed at temperatures below zero degree.
- Hogan, V F,O'Hagan, D,Sanvoisin, J
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p. 883 - 885
(2007/10/02)
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- Studies on the Chemo- and Enantio-selectivity of the Enzymatic Monoacylations of Amino Alcohols
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The formation of ω-aminoalkyl esters through the lipase PS (Pseudomonas cepacia)-catalysed transesterification between carboxylic acid esters 1-6 and ω-amino-1-alkanols in tert-amyl alcohol has been studied.For n = 5 or 6 the reaction practically leads to the formation of the ester product.The ester/amide ratios decrease with decreasing n so that for n = 3 only the amide product is obtained.A moderate kinetic resolution (ca. 50percent e.e. at 50percent conversion) was found in the acylations with two of the racemic starting esters (3 and 4).
- Kanerva, Liisa T.,Kosonen, Markus,Vaenttinen, Eero,Huuhtanen, Tuomas T.,Dahlqvist, Martti
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p. 1101 - 1105
(2007/10/02)
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- Organometallic substrates of enzymes: lipase catalysed transesterifications in organic solvents via O-stannyl ethers
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Lipases from pig pancreas and from Chromobacterium viscosum (but not from Candida cylindracea) catalyze transesterification reactions between ethyl esters of carboxylic acids and tributylstannyl ethers of primary and secondary alcohols.At concentrations 1M or higher in anhydrous hydrocarbons, use of these nucleophilic derivatives of alcohols gives reaction rates ca. three times higher than those for the corresponding alcohols.
- Therisod, Michel
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