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Asymmetric and Selective Biocatalysis

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ISBN: 9783038978466 9783038978473 Year: Pages: 154 DOI: 10.3390/books978-3-03897-847-3 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-06-26 09:16:44
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This Issue contains one communication, six articles, and two reviews. The communication from Paola Vitale et al. represents a work where whole cells were used as biocatalysts for the reduction of optically active chloroalkyl arylketones followed by a chemical cyclization to give the desired heterocycles. Among the various whole cells screened (baker’s yeast, Kluyveromyces marxianus CBS 6556, Saccharomyces cerevisiae CBS 7336, Lactobacillus reuteri DSM 20016), baker’s yeast provided the best yields and the highest enantiomeric ratios (95:5) in the bioreduction of the above ketones. In this respect, valuable chiral non-racemic functionalized oxygen-containing heterocycles (e.g., (S)-styrene oxide, (S)-2-phenyloxetane, (S)-2-phenyltetrahydrofuran), amenable to be further elaborated on, can be smoothly and successfully generated from their prochiral precursors. Studies about pure biocatalysts with mechanistical studies, application in different reactions, and new immobilization methods for improving their stability were reported in five different articles. The article by Su-Yan Wang et al. describes the cloning, expression, purification, and characterization of an N-acetylglucosamine 2-epimerase from Pedobacter heparinus (PhGn2E). For this, several N-acylated glucosamine derivatives were chemically synthesized and used to test the substrate specificity of the enzyme. The mechanism of the enzyme was studied by hydrogen/deuterium NMR. The study at the anomeric hydroxyl group and C-2 position of the substrate in the reaction mixture confirmed the epimerization reaction via ring-opening/enolate formation. Site-directed mutagenesis was also used to confirm the proposed mechanism of this interesting enzyme. The article by Forest H. Andrews et al. studies two enzymes, benzoylformate decarboxylase (BFDC) and pyruvate decarboxylase (PDC), which catalyze the non-oxidative decarboxylation of 2-keto acids with different specificity. BFDC from Pseudomonas putida exhibited very limited activity with pyruvate, whereas the PDCs from S. cerevisiae or from Zymomonas mobilis showed virtually no activity with benzoylformate (phenylglyoxylate). After studies using saturation mutagenesis, the BFDC T377L/A460Y variant was obtained, with 10,000-fold increase in pyruvate/benzoylformate. The change was attributed to an improvement in the Km value for pyruvate and a decrease in the kcat value for benzoylformate. The characterization of the new catalyst was performed, providing context for the observed changes in the specificity. The article by Xin Wang et al. compares two types of biocatalysts to produce D-lysine L-lysine in a cascade process catalyzed by two enzymes: racemase from microorganisms that racemize L-lysine to give D,L-lysine and decarboxylase that can be in cells, permeabilized cells, and the isolated enzyme. The comparison between the different forms demonstrated that the isolated enzyme showed the higher decarboxylase activity. Under optimal conditions, 750.7 mmol/L D-lysine was finally obtained from 1710 mmol/L L-lysine after 1 h of racemization reaction and 0.5 h of decarboxylation reaction. D-lysine yield could reach 48.8% with enantiomeric excess (ee) of 99%. In the article by Rivero and Palomo, lipase from Candida rugosa (CRL) was highly stabilized at alkaline pH in the presence of PEG, which permitted its immobilization for the first time by multipoint covalent attachment on different aldehyde-activated matrices. Different covalent immobilized preparation of the enzyme was successfully obtained. The thermal and solvent stability was highly increased by this treatment, and the novel catalysts showed high regioselectivity in the deprotection of per-O-acetylated nucleosides. The article by Robson Carlos Alnoch et al. describes the protocol and use of a new generation of tailor-made bifunctional supports activated with alkyl groups that allow the immobilization of proteins through the most hydrophobic region of the protein surface and aldehyde groups that allows the covalent immobilization of the previously adsorbed proteins. These supports were especially used in the case of lipase immobilization. The immobilization of a new metagenomic lipase (LipC12) yielded a biocatalyst 3.5-fold more active and 5000-fold more stable than the soluble enzyme. The PEGylated immobilized lipase showed high regioselectivity, producing high yields of the C-3 monodeacetylated product at pH 5.0 and 4 °C. Hybrid catalysts composed of an enzyme and metallic complex are also treated in this Special Issue. The article by Christian Herrero et al. describes the development of the Mn(TpCPP)-Xln10A artificial metalloenzyme, obtained by non-covalent insertion of Mn(III)-meso-tetrakis(p-carboxyphenyl)porphyrin [Mn(TpCPP), 1-Mn] into xylanase 10A from Streptomyces lividans (Xln10A). The complex was found able to catalyze the selective photo-induced oxidation of organic substrates in the presence of [RuII(bpy)3]2+ as a photosensitizer and [CoIII(NH3)5Cl]2+ as a sacrificial electron acceptor, using water as oxygen atom source. The two published reviews describe different subjects with interest in the fields of biocatalysis and mix metallic-biocatalysis, respectively. The review by Anika Scholtissek et al. describes the state-of-the-art regarding ene-reductases from the old yellow enzyme family (OYEs) to catalyze the asymmetric hydrogenation of activated alkenes to produce chiral products with industrial interest. The dependence of OYEs on pyridine nucleotide coenzyme can be avoided by using nicotinamide coenzyme mimetics. In the review, three main classes of OYEs are described and characterized. The review by Yajie Wang and Huimin Zhao highlights some of the recent examples in the past three years that combine transition metal catalysis with enzymatic catalysis. With recent advances in protein engineering, catalyst synthesis, artificial metalloenzymes, and supramolecular assembly, there is great potential to develop more sophisticated tandem chemoenzymatic processes for the synthesis of structurally complex chemicals. In conclusion, these nine publications give an overview of the possibilities of different catalysts, both traditional biocatalysts and hybrids with metals or organometallic complexes to be used in different processes—particularly in synthetic reactions—under very mild reaction conditions.

Role of Natural Compounds in Inflammation and Inflammatory-Related Diseases

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ISBN: 9783039215522 9783039215539 Year: Pages: 174 DOI: 10.3390/books978-3-03921-553-9 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-12-09 11:49:15
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The papers reported here will contribute to proposing new insights into the mechanisms of several conditions, as well as suggesting new diagnostic alternatives and therapeutic targets in widespread pathologies such inflammation and inflammatory-based diseases. The discovery of the new is, as always, anchored in recourse to the old.

Biocatalysis and Pharmaceuticals: A Smart Tool for Sustainable Development

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ISBN: 9783039217083 9783039217090 Year: Pages: 176 DOI: 10.3390/books978-3-03921-709-0 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- Biotechnology
Added to DOAB on : 2019-12-09 11:49:16
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Biocatalysis, that is, the use of biological catalysts (enzymes, cells, etc.) for the preparation of highly valuable compounds is undergoing a great development, being considered an extremely sustainable approach to undertaking environmental demands. In this scenario, this book illustrates the versatility of applied biocatalysis for the preparation of drugs and other bioactive compounds through the presentation of different research articles and reviews, in which several authors describe the most recent developments in this appealing scientific area. By reading the excellent contributions gathered in this book, it is possible to have an updated idea about new advances and possibilities for a new exciting future.

Advances in Food and By-Products Processing Towards a Sustainable Bioeconomy

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ISBN: 9783039217526 9783039217533 Year: Pages: 146 DOI: 10.3390/books978-3-03921-753-3 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- Biotechnology
Added to DOAB on : 2020-01-07 09:08:26
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The bioeconomy initially focused on resource substitution, including the production of biomass from various resources; its conversion, fractionation, and processing by means of biotechnology; and chemistry and process engineering towards the production and marketing of food, feed, fuel, and fibre. Nevertheless, although resource substitution is still considered important, the emphasis has been recently shifted to the biotechnological innovation perspective of the bioeconomy, in terms that ensure environmental sustainability. It is estimated that around one-third of the food produced for human consumption is wasted throughout the world, posing not only a sustainability problem related to food security but also a significant environmental problem. Food waste streams, mainly derived from fruits and vegetables, cereals, oilseeds, meat, dairy, and fish processing, have unavoidably attracted the interest of the scientific community as an abundant reservoir of complex carbohydrates, proteins, lipids, and functional compounds, which can be utilized as raw materials for added-value product formulations. This Special Issue focuses on innovative and emerging food and by-products processing methods for the sustainable transition to a bioeconomy era.

Organophosphorus Chemistry 2018

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ISBN: 9783039282364 9783039282371 Year: Pages: 601 DOI: 10.3390/books978-3-03928-237-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General) --- Organic Chemistry
Added to DOAB on : 2020-04-07 23:07:08
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Organophosphorus chemistry is an important discipline within organic chemistry. Phosphorus compounds, such as phosphines, trialkyl phosphites, phosphine oxides (chalcogenides), phosphonates, phosphinates and >P(O)H species, etc., may be important starting materials or intermediates in syntheses. Let us mention the Wittig reaction and the related transformations, the Arbuzov- and the Pudovik reactions, the Kabachnik–Fields condensation, the Hirao reaction, the Mitsunobu reaction, etc. Other reactions, e.g., homogeneous catalytic transformations or C-C coupling reactions involve P-ligands in transition metal (Pt, Pd, etc.) complex catalysts. The synthesis of chiral organophosphorus compounds means a continuous challenge. Methods have been elaborated for the resolution of tertiary phosphine oxides and for stereoselective organophosphorus transformations. P-heterocyclic compounds, including aromatic and bridged derivatives, P-functionalized macrocycles, dendrimers and low coordinated P-fragments, are also of interest. An important segment of organophosphorus chemistry is the pool of biologically-active compounds that are searched and used as drugs, or as plant-protecting agents. The natural analogue of P-compounds may also be mentioned. Many new phosphine oxides, phosphinates, phosphonates and phosphoric esters have been described, which may find application on a broad scale. Phase transfer catalysis, ionic liquids and detergents also have connections to phosphorus chemistry. Green chemical aspects of organophosphorus chemistry (e.g., microwave-assisted syntheses, solvent-free accomplishments, optimizations, and atom-efficient syntheses) represent a dynamically developing field. Last, but not least, theoretical approaches and computational chemistry are also a strong sub-discipline within organophosphorus chemistry.

Amide Bond Activation

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ISBN: 9783039212033 9783039212040 Year: Pages: 466 DOI: 10.3390/books978-3-03921-204-0 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-08-28 11:21:27
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The amide bond represents a privileged motif in chemistry. The recent years have witnessed an explosion of interest in the development of new chemical transformations of amides. These developments cover an impressive range of catalytic N–C bond activation in electrophilic, Lewis acid, radical, and nucleophilic reaction pathways, among other transformations. Equally relevant are structural and theoretical studies that provide the basis for chemoselective manipulation of amidic resonance. This monograph on amide bonds offers a broad survey of recent advances in activation of amides and addresses various approaches in the field.

Keywords

fumardiamide --- primaquine --- succindiamide --- Michael acceptor --- biofilm eradication --- antibacterial screening --- antiviral activity --- cytostatic activity --- N,N-dimethylformamide --- DMF --- N,N-dimethylacetamide --- DMAc --- amination --- amidation --- thioamidation --- formylation --- carbonylation --- cyanation --- insertion --- cyclization --- amide --- arynes --- insertion --- activation --- heterocycles --- organic synthesis --- multi-component coupling reaction --- aryl thioamides --- thiourea --- C-H/C-N activation --- C-S formation --- transition-metal-free --- rotational barrier energy --- amide bond --- nuclear magnetic resonance --- kinetic --- density functional theory --- non planar amide --- base-catalyed hydrolysis --- water solvation --- entropy --- transamidation --- amide --- amine --- catalyst --- catalysis --- acylative cross-coupling --- trialkylborane --- amide activation --- palladium --- N-heterocyclic carbene --- ruthenium (Ru) --- N-heterocyclic carbenes (NHCs) --- homogeneous catalysis --- in situ --- amide bonds --- synthesis --- density functional theory --- cis/trans isomerization --- secondary amides --- dipeptides --- steric effects --- tert-butyl --- additivity principle --- amino acid transporters --- amide bond --- gemcitabine prodrug --- metabolic stability --- pancreatic cancer cells --- pharmacokinetics --- peptide bond cleavage --- amide bond resonance --- twisted amides --- enzymes --- metal complexes --- catalysts --- amide C–N bond activation --- nickel catalysis --- amidation --- DFT study --- reaction thermodynamics --- amide resonance --- anomeric effect --- HERON reaction --- pyramidal amides --- physical organic chemistry --- reaction mechanism --- amide --- activation --- amidicity --- carbonylicity --- transamidation --- acyl transfer --- excited state --- Suzuki-Miyaura --- cross-coupling --- aryl esters --- C–O activation --- Pd-catalysis --- amides --- carbanions --- C–H acidity --- nitro-aci tautomerism --- molecular dynamics --- density-functional theory --- alkynes --- C–H bond cleavage --- C–N bond cleavage --- cyclopentadienyl complexes --- N-(1-naphthyl)acetamide --- rhodium --- [2+2+2] annulation --- amide bond --- sulfonamide bond --- alkynes --- addition reaction --- aminoacylation --- aminosulfonylation --- pre-catalysts --- palladium catalysis --- amide bond activation --- ester bond activation --- cross-coupling --- amide bond --- bridged lactams --- twisted amides --- amides --- Winkler-Dunitz parameters --- N–C activation --- hypersensitivity --- nitrogen heterocycles --- distortion --- bridged sultams --- amides --- C-N ? bond cleavage --- sodium --- crown ether --- amide hydrolysis --- model compound --- intramolecular catalysis --- twisted amide --- protease --- intein --- C-H functionalization --- directing groups --- amides --- transition metals --- catalysis

Recent Advances in Biocatalysis and Metabolic Engineering for Biomanufacturing

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ISBN: 9783039215744 9783039215751 Year: Pages: 278 DOI: 10.3390/books978-3-03921-575-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- Biotechnology
Added to DOAB on : 2019-12-09 11:49:15
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The use of biocatalysts, including enzymes and metabolically engineered cells, has attracted a great deal of attention in the chemical and bio-industry, because biocatalytic reactions can be conducted under environmentally-benign conditions and in more sustainable ways. The catalytic efficiency and chemo-, regio-, and stereo-selectivity of enzymes can be enhanced and modulated using protein engineering. Metabolic engineering seeks to enhance cellular biosynthetic productivity of target metabolites via controlling and redesigning metabolic pathways using multi-omics analysis, genome-scale modeling, metabolic flux control, and reconstruction of novel pathways. The aim of this book is to cover the recent advances in biocatalysis and metabolic engineering for biomanufacturing of biofuels, chemicals, biomaterials, and pharmaceuticals. Reviews and original research articles on the development of new strategies to improve the catalytic efficiency of enzymes, biosynthetic capability of cell factories, and their applications in production of various bioproducts and chemicals are included.

Keywords

artificial self-sufficient P450 --- bioplastics --- dodecanoic acid --- Nylon 12 --- ?-aminododecanoic acid --- immobilization --- fluorescein diacetate --- polyurethane foam --- biofilm --- total enzymatic activity --- biocatalysis --- Combi-CLEAs --- cascade reactions --- immobilization --- Myceliophthora --- glyoxal oxidase --- 5-hydroxymethylfurfural --- aerobic methane bioconversion --- bioreactor --- string film reactor --- mass transfer performance --- cross-linked enzyme aggregate --- amyloglucosidase --- magnetic nanoparticles --- bovine serum albumin --- polyethyleneimine --- starch hydrolysis --- Eversa --- interfacial activation --- lipase immobilization --- enzyme stabilization --- enzyme modulation --- metabolic engineering --- synthetic biology --- 3-hydroxypropionic acid --- microbial production --- fatty acid synthesis --- acetate --- redox enzymes --- FTIR spectroscopy --- small molecules --- Corynebacterium glutamicum --- Pvgb --- tunable expression system --- expression vectors --- synthetic biology --- Vitreoscilla --- vgb --- biocatalysts --- biocatalytic reaction --- Methylosinus sporium strain 5 --- soluble methane monooxygenase --- C–H activation --- O2 activation --- synthetic biology --- metabolic engineering --- microbial cell factory --- synthetic metabolic pathways --- mannose --- magnetic nanoparticles --- immobilization --- whole cell --- specific recognition --- 12-hydroxydodecanoic acid --- dodecanoic acid --- CYP153A --- whole-cell biotransformation --- Candida antarctica Lipase B --- transesterification --- polymer functionalization --- tetraethylene glycol --- poly(ethylene glycol) --- hydrogenase --- bio-hydrogen --- chemicals addition --- review --- (?)-?-bisabolol --- mevalonate (MVA) --- mevalonate kinase 1 --- Methanosarcina mazei --- fed-batch fermentation --- monoterpene --- prokaryotic microbial factory --- metabolic engineering --- MEP pathway --- MEV pathway --- n/a

Biofuel and Bioenergy Technology

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ISBN: 9783038975960 Year: Pages: 425 DOI: 10.3390/books978-3-03897-597-7 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2019-03-21 14:08:22
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The subject of this book is ""Biofuel and Bioenergy Technology"". It aims to publish high-quality review and research papers, addressing recent advances in biofuel and bioenergy. State-of-the-art studies of advanced techniques of biorefinery for biofuel production are also included. Research involving experimental studies, recent developments, and novel and emerging technologies in this field are covered. This book contains twenty-seven technical papers which cover diversified biofuel and bioenergy technology-related research that have shown critical results and contributed significant findings to the fields of biomass processing, pyrolysis, bio-oil and its emulsification; transesterification and biodiesel, gasification and syngas, fermentation and biogas/methane, bioethanol and alcohol-based fuels, solid fuel and biochar, and microbial fuel cell and power generation development. The published contents relate to the most important techniques and analyses applied in the biofuel and bioenergy technology.

Keywords

air-steam gasification --- equilibrium model --- tar --- energy exchange --- exergy efficiency --- bio-electro-Fenton microbial fuel cells (Bio-E-Fenton MFCs) --- wastewater --- photo catalyst --- degradation --- calcination --- chemical oxygen demand (COD) --- MFC --- hydrodynamic boundary layer --- recirculation mode --- shear rate --- voltage --- charge transfer resistance --- biodiesel --- direct transesterification --- Rhodotorula glutinis --- single cell oil --- biogas --- tri-reforming process --- syngas --- methane and carbon dioxide conversion --- hydrogen/carbon monoxide ratio --- first-law/second-law efficiency --- biodiesel --- esterification --- liquid lipase --- superabsorbent polymer --- response surface methodology --- waste wood --- torrefaction --- energy yield --- mass yield --- CHO index --- gross calorific value --- Van Krevelen diagram --- anaerobic digestion --- biogas production --- wastewater treatment --- membrane bioreactors --- anaerobic digestion --- methane --- carbon dioxide --- small-scale biogas plants --- developing countries --- SOFC --- validation --- simulation --- exergy --- syngas --- Chlorella --- coal-fired flue-gas --- screening --- biodiesel property --- mixotrophic cultivation --- thermophilic anaerobic digestion --- corn stover --- prairie cord grass --- unbleached paper --- digester performance --- process stability --- synergistic effects --- microbial community --- Methanothermobacter --- biochemical methane potential --- redox potential reduction --- direct interspecies electron transfer --- electroactive biofilm --- Nejayote --- granular activated carbon --- Jerusalem artichoke --- lignocellulose --- acid pretreatment --- nitric acid --- alkali pretreatment --- enzymatic hydrolysis --- ethanol fermentation --- waste biomass --- Vietnam --- solid biofuel --- calorific value --- mechanical durability --- fatty acid methyl ester --- catalyst --- viscosity --- iodine value --- acidity index --- sewage sludge --- pyrolytic oil --- Taguchi method --- thermogravimetric analysis --- synergistic effect --- combined pretreatment --- ball mill --- ethanol organosolv --- herbaceous biomass --- lignin recovery --- Annona muricata --- biodiesel production --- seed oil --- soursop --- two-step process --- response surface methodology --- RSM --- second-generation biodiesel --- stone fruit --- optimisation --- biodiesel testing --- transesterification --- lignocellulosic biomass --- Miscanthus --- mechanical pretreatment --- organosolv pretreatment --- microbial biofuel --- metabolic engineering --- alkanes --- alcohols --- acetone --- electrochemical hydrogenation --- isopropanol --- membrane contamination --- polymer electrolyte membrane --- relative humidity --- diesel --- Carica papaya --- engine performance --- biodiesel --- characterisation --- porosity --- thermophoretic force --- biomass fuel --- non-premixed combustion --- counter-flow structure --- mathematical modeling --- emulsification --- liquefaction --- bio-oils --- co-surfactant --- surfactant --- diesel --- biogas --- Clostridiales --- hydrogen-producing bacteria --- bioreactors --- anaerobic fermentation --- anaerobic digestion --- microbial community composition

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