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Artigos de revistas sobre o assunto "Furanic acid"
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Margellou, Antigoni G., Stylianos A. Torofias, Georgios Iakovou e Konstantinos S. Triantafyllidis. "Valorization of Chlorella Microalgae Residual Biomass via Catalytic Acid Hydrolysis/Dehydration and Hydrogenolysis/Hydrogenation". Catalysts 14, n.º 5 (23 de abril de 2024): 286. http://dx.doi.org/10.3390/catal14050286.
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Microalgal biomass can be utilized for the production of value-added chemicals and fuels. Within this research, Chlorella vulgaris biomass left behind after the extraction of lipids and proteins was converted to valuable sugars, organic acids and furanic compounds via hydrolysis/dehydration using dilute aqueous sulfuric acid as a homogeneous catalyst. Under mild conditions, i.e., low temperature and low sulfuric acid concentration, the main products of hydrolysis/dehydration were monomeric sugars (glucose and xylose) and furanic compounds (HMF, furfural) while under more intense conditions (i.e., higher temperature and higher acid concentration), organic acids (propionic, formic, acetic, succinic, lactic, levulinic) were also produced either directly from sugar conversion or via intermediate furans. As a second valorization approach, the residual microalgal biomass was converted to value-added sugar alcohols (sorbitol, glycerol) via hydrogenation/hydrogenolysis reactions over metallic ruthenium catalysts supported on activated carbons (5%Ru/C). It was also shown that a low concentration of sulfuric acid facilitated the conversion of biomass to sugar alcohols by initiating the hydrolysis of carbohydrates to monomeric sugars. Overall, this work aims to propose valorization pathways for a rarely utilized residual biomass towards useful compounds utilized as platform chemicals and precursors for the production of a wide variety of solvents, polymers, fuels, food ingredients, pharmaceuticals and others.
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Marshall, Adam, Bo Jiang, Régis M. Gauvin e Christophe M. Thomas. "2,5-Furandicarboxylic Acid: An Intriguing Precursor for Monomer and Polymer Synthesis". Molecules 27, n.º 13 (24 de junho de 2022): 4071. http://dx.doi.org/10.3390/molecules27134071.
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The most versatile furanic building block for chemical and polymer applications is 2,5-furandicarboxylic acid. However, the classical 2,5-furandicarboxylic acid production methodology has been found to have significant drawbacks that hinder industrial-scale production. This review highlights new alternative methods to synthesize 2,5-furandicarboxylic acid that are both more advantageous and attractive than conventional oxidation of 5-hydroxymethylfurfural. This review also focuses on the use of 2,5-furandicarboxylic acid as a polymer precursor and the various potential applications that arise from these furan-based materials.
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Antunes, Margarida M., Andreia F. Silva, Carolina D. Bernardino, Auguste Fernandes, Filipa Ribeiro e Anabela A. Valente. "Catalytic Transfer Hydrogenation and Acid Reactions of Furfural and 5-(Hydroxymethyl)furfural over Hf-TUD-1 Type Catalysts". Molecules 26, n.º 23 (27 de novembro de 2021): 7203. http://dx.doi.org/10.3390/molecules26237203.
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Heterogeneous catalysis, which has served well the petrochemical industry, may valuably contribute towards a bio-based economy by sustainably enabling selective reactions to renewable chemicals. Carbohydrate-containing matter may be obtained from various widespread sources and selectively converted to furanic platform chemicals: furfural (Fur) and 5-(hydroxymethyl)furfural (Hmf). Valuable bioproducts may be obtained from these aldehydes via catalytic transfer hydrogenation (CTH) using alcohols as H-donors under relatively moderate reaction conditions. Hafnium-containing TUD-1 type catalysts were the first of ordered mesoporous silicates explored for the conversion of Fur and Hmf via CTH/alcohol strategies. The materials promoted CTH and acid reactions leading to the furanic ethers. The bioproducts spectrum was broader for the reaction of Fur than of Hmf. A Fur reaction mechanism based on literature data was discussed and supported by kinetic modelling. The influence of the Hf loading and reaction conditions (catalyst load, type of alcohol H-donor, temperature, initial substrate concentration) on the reaction kinetics was studied. The reaction conditions were optimized to maximize the yields of 2-(alkoxymethyl)furan ethers formed from Fur; up to 63% yield was reached at 88% Fur conversion, 4 h/150 °C, using Hf-TUD-1(75), which was a stable catalyst. The Hf-TUD-1(x) catalysts promoted the selective conversion of Hmf to bis(2-alkoxymethyl)furan; e.g., 96% selectivity at 98% Hmf conversion, 3 h/170 °C for Hf-TUD-1(50).
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Klushin, V. A., U. A. Chus e Nina Smirnova. "Synthesis of Furanic Polyamides and Composite Coatings from Plant Biomass". Key Engineering Materials 816 (agosto de 2019): 84–89. http://dx.doi.org/10.4028/www.scientific.net/kem.816.84.
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We report, for the first time, the synthesis of polyamide composite coating based on renewable plant biomass sources. 2,5-furandicarboxylic acid (FDCA) was prepared by catalytic oxidation of 5-hydroxymethylfurfural (HMF) obtained by plant biomass conversion. FDCA was used in the synthesis of aliphatic and aromatic furanic polyamides. Two approaches to furanic PAs synthesis have been investigated: (i) synthesis of hexamethylenediamine furanoate salt and its subsequent polycondensation; (ii) synthesis of FDCA dichloride and its subsequent polycondensation in a two-phase aqueous-organic system. The effect of the nature of organic solvent (tetraclormetan, dichloromethane, N-methyl-2-pyrrolidone) and the nature of diamine (hexamethylenediamine and paraphenylenediamine) on the yield and molecular weight of furanic polyamide was studied. The synthesized aliphatic polyamide was used for enamel fabrication. Colloidal graphite and activated carbon obtained from the waste of biomass conversion into HMF were used as fillers. The furanic PA composite coatings on steel provide the lower coefficient of friction and lower wear compared with that of commercial polyamide (PA6) coatings and can be considered as novel promising anti-friction coating materials.
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Zhang, Bengang, Mathieu Petrissans, Anelie Petrissans, Antonio Pizzi e Baptiste Colin. "Furanic Polymerization Causes the Change, Conservation and Recovery of Thermally-Treated Wood Hydrophobicity before and after Moist Conditions Exposure". Polymers 15, n.º 1 (31 de dezembro de 2022): 221. http://dx.doi.org/10.3390/polym15010221.
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The Whilhelmy method of contact angle, wood thermal properties (TG/DTG), infrared spectroscopy, etc. was used to define the hydrophobicity of heat-treated beech and fir wood at increasing temperatures between 120 °C and 300 °C. By exposure to wet conditions during 1 week, the hydrophobic character obtained by the heat treatment remains constant heat-treated. Heat induced wood hydrophobation, was shown by CP MAS 13C NMR and MALDI ToF mass spectrometry to be mainly caused by furanic moieties produced from heat-induced hemicelluloses degradation. This is caused by the acid environment generated by the hydrolysis of the hemicelluloses acetyl groups. Furfural polymerizes to linear and branched oligomers and finally to water repellent, insoluble furanic resins. The water repellent, black colored, cross-linked polymerized furanic network is present throughout the heat-treated wood. Wood darkening as well as its water repellency due to increasing proportions of black colored furanic resins increase as a function of the increase with treating temperature, becoming particularly evident in the 200 to 300 °C treating temperature range.
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Gumidyala, Abhishek, Bin Wang e Steven Crossley. "Direct carbon-carbon coupling of furanics with acetic acid over Brønsted zeolites". Science Advances 2, n.º 9 (setembro de 2016): e1601072. http://dx.doi.org/10.1126/sciadv.1601072.
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Effective carbon-carbon coupling of acetic acid to form larger products while minimizing CO2emissions is critical to achieving a step change in efficiency for the production of transportation fuels from sustainable biomass. We report the direct acylation of methylfuran with acetic acid in the presence of water, all of which can be readily produced from biomass. This direct coupling limits unwanted polymerization of furanics while producing acetyl methylfuran. Reaction kinetics and density functional theory calculations illustrate that the calculated apparent barrier for the dehydration of the acid to form surface acyl species is similar to the experimentally measured barrier, implying that this step plays a significant role in determining the net reaction rate. Water inhibits the overall rate, but selectivity to acylated products is not affected. We show that furanic species effectively stabilize the charge of the transition state, therefore lowering the overall activation barrier. These results demonstrate a promising new route to C–C bond–forming reactions for the production of higher-value products from biomass.
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Salis, Severyn, Nadia Spano, Marco Ciulu, Ignazio Floris, Maria I. Pilo e Gavino Sanna. "Electrochemical Determination of the “Furanic Index” in Honey". Molecules 26, n.º 14 (6 de julho de 2021): 4115. http://dx.doi.org/10.3390/molecules26144115.
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5-(hydroxymethyl)furan-2-carbaldehyde, better known as hydroxymethylfurfural (HMF), is a well-known freshness parameter of honey: although mostly absent in fresh samples, its concentration tends to increase naturally with aging. However, high quantities of HMF are also found in fresh but adulterated samples or honey subjected to thermal or photochemical stresses. In addition, HMF deserves further consideration due to its potential toxic effects on human health. The processes at the origin of HMF formation in honey and in other foods, containing saccharides and proteins—mainly non-enzymatic browning reactions—can also produce other furanic compounds. Among others, 2-furaldehyde (2F) and 2-furoic acid (2FA) are the most abundant in honey, but also their isomers (i.e., 3-furaldehyde, 3F, and 3-furoic acid, 3FA) have been found in it, although in small quantities. A preliminary characterization of HMF, 2F, 2FA, 3F, and 3FA by cyclic voltammetry (CV) led to hypothesizing the possibility of a comprehensive quantitative determination of all these compounds using a simple and accurate square wave voltammetry (SWV) method. Therefore, a new parameter able to provide indications on quality of honey, named “Furanic Index” (FI), was proposed in this contribution, which is based on the simultaneous reduction of all analytes on an Hg electrode to ca. −1.50 V vs. Saturated Calomel Electrode (SCE). The proposed method, validated, and tested on 10 samples of honeys of different botanical origin and age, is fast and accurate, and, in the case of strawberry tree honey (Arbutus unedo), it highlighted the contribution to the FI of the homogentisic acid (HA), i.e., the chemical marker of the floral origin of this honey, which was quantitatively reduced in the working conditions. Excellent agreement between the SWV and Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) data was observed in all samples considered.
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Holewinski, Adam. "Electro-Oxidative Valorization of Biomass-Derived Furanics". ECS Meeting Abstracts MA2023-02, n.º 27 (22 de dezembro de 2023): 1428. http://dx.doi.org/10.1149/ma2023-02271428mtgabs.
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Electrocatalysis poses many potential advantages for distributed scale biomass valorization. Furanic biomass derivatives such as furfural and 5-hydroxymethylfurfural (HMF) can provide access to a number of value-added chemicals by partial oxidation, including furoic acid, maleic acid, and 2,5-furandicarboxylic acid (FDCA). Here, we have utilized differential reactor studies with online electrochemical mass spectrometry (OLEMS), as well as in-situ attenuated total reflectance surface enhanced infrared reflection absorption spectroscopy (ATR-SEIRAS), to probe these reaction pathways on various metal electrodes. Experimental insights are combined with computational results to piece together plausible mechanisms. We find tradeoffs between decarbonylation activity and self-assembly of furoate intermediates on late transition metals to be critical selectivity-determining and rate-determining process. We also characterize oxidative dehydrogenation paths for furanic aldehydes, which co-produce (anodic) hydrogen gas. Strategies for improved catalyst design will be discussed.
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Luo, Kaiju, Yan Wang, Junrong Yu, Jing Zhu e Zuming Hu. "Semi-bio-based aromatic polyamides from 2,5-furandicarboxylic acid: toward high-performance polymers from renewable resources". RSC Advances 6, n.º 90 (2016): 87013–20. http://dx.doi.org/10.1039/c6ra15797a.
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Zhao, Deyang, Frederic Delbecq e Christophe Len. "One-Pot FDCA Diester Synthesis from Mucic Acid and Their Solvent-Free Regioselective Polytransesterification for Production of Glycerol-Based Furanic Polyesters". Molecules 24, n.º 6 (15 de março de 2019): 1030. http://dx.doi.org/10.3390/molecules24061030.
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A one pot-two step procedure for the synthesis of diethyl furan-2,5-dicarboxylate (DEFDC) starting from mucic acid without isolation of the intermediate furan dicarboxylic acid (FDCA) was studied. Then, the production of three different kinds of furan-based polyesters— polyethylene-2,5-furan dicarboxylate (PEF), polyhydropropyl-2,5-furan dicarboxylate(PHPF) and polydiglycerol-2,5-furandicarboxylate (PDGF)—was realized through a Co(Ac)2·4H2O catalyzed polytransesterification performed at 160 °C between DEFDC and a defined diol furan-based prepolymer or pure diglycerol. In parallel to polymerization process, an unattended regioselective 1-OH acylation of glycerol by direct microwave-heated FDCA diester transesterification led to the formation of a symmetric prepolymer ready for further polymerization and clearly identified by 2D NMR sequences. Furthermore, the synthesis of a more soluble and hydrophilic diglycerol-based furanic polyester was also achieved. The resulting biobased polymers were characterized by NMR, FT-IR spectroscopy, DSC, TGA and XRD. The morphologies of the resulted polymers were observed by FE-SEM and the purity of the material by EDX.
Teses / dissertações sobre o assunto "Furanic acid"
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Antunes, Maria Margarida Feitor Pintão Moreno. "Catalytic routes to convert saccharides to furanic aldehydes". Doctoral thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/12500.
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Doutoramento em QuímicaThe conversion of plant biomass-derived carbohydrates (preferably non-edible) into added-value products is envisaged to be at the core of the future biorefineries. Carbohydrates are the most abundant natural organic polymers on Earth. This work deals with the chemical valorisation of plant biomass, focusing on the acid-catalysed conversion of carbohydrates (mono and polysaccharides) to furanic aldehydes, namely 2-furaldehyde (Fur) and 5-hydroxymethyl-2-furaldehyde (Hmf), which are valuable platform chemicals that have the potential to replace a variety of oil derived chemicals and materials. The investigated reaction systems can be divided into two types depending on the solvent used to dissolve the carbohydrates in the reaction medium: water or ionic liquid-based systems. The reaction temperatures were greater than 150 ºC when the solvent was water, and lower than 150 º C in the cases of the ionic liquid-based catalytic systems. As alternatives to liquid acids (typically used in the industrial production of Fur), solid acid catalysts were investigated in these reaction systems. Aiming at the identification of (soluble and insoluble) reaction products, complementary characterisation techniques were used namely, FT-IR spectroscopy, liquid and solid state NMR spectroscopy, TGA, DSC and GC´GC-ToFMS analyses. Complex mixtures of soluble reaction products were obtained and different types of side reactions may occur. The requirements to be put on the catalysts for these reaction systems partly depend on the type of carbohydrates to be converted and the reaction conditions used. The thermal stability is important due to the fact that formation of humins and catalyst coking phenomena are characteristically inherent to these types of reactions systems leading to the need to regenerate the catalyst which can be effectively accomplished by calcination. Special attention was given to fully inorganic nanoporous solid acids, amorphous or crystalline, and consisting of nano to micro-size particles. The investigated catalysts were silicoaluminophosphates, aluminosilicates and zirconium-tungsten mixed oxides which are versatile catalysts in that their physicochemical properties can be fine-tuned to improve the catalytic performances in the conversion of different substrates (e.g. introduction of mesoporosity and modification of the acid properties). The catalytic systems consisting of aluminosilicates as solid acids and water as solvent seem to be more effective in converting pentoses and related polysaccharides into Fur, than hexoses and related polysaccharides into Hmf. The investigated solid acids exhibited fairly good hydrothermal stabilities. On the other hand, ionic liquid-based catalytic systems can allow reaching simultaneously high Fur and Hmf yields, particularly when Hmf is obtained from D-fructose and related polysaccharides; however, catalyst deactivation occurs and the catalytic reactions take place in homogeneous phase. As pointed out in a review of the state of the art on this topic, the development of truly heterogeneous ionic liquid-based catalytic systems for producing Fur and Hmf in high yields remains a challenge.
Os carboidratos constituem os polímeros naturais mais abundantes na Terra, e a sua valorização química é de grande interesse no contexto das biorefinarias. O objetivo deste trabalho centrou-se na conversão de carboidratos (monossacarídeos e polissacarídeos) em 2-furaldeído (Fur) e 5-hidroximetil-2-furaldeído (Hmf) na presença de catalisadores ácidos, em reatores descontínuos. Fur e Hmf são considerados compostos “plataforma” porque podem ser convertidos numa grande variedade de produtos químicos e materiais (alternativos aos derivados do petróleo). Testaram-se catalisadores ácidos heterogéneos como alternativa aos ácidos minerais que são comumente usados como catalisadores homogéneos para a produção industrial do Fur. Por outro lado utilizou-se água ou um líquido iónico como solvente para a dissolução dos carboidratos no meio reacional. As temperaturas reacionais foram superiores a 150 ºC quando o solvente era a água, e inferiores a 150 ºC no caso de líquidos iónicos. Com o intuito de identificar os produtos reacionais (solúveis e insolúveis), utilizaram-se diferentes técnicas nomeadamente espetroscopia de infravermelho, espetroscopia de RMN de estado líquido e sólido, TGA, DSC e GCxGC-ToFMS. Obtiveram-se misturas complexas de produtos reacionais e discutiram-se aspetos mecanísticos. A estabilidade térmica do catalisador é importante uma vez que a formação de matéria carbonácea insolúvel é característica destes sistemas reacionais tornando-se necessário proceder à regeneração do catalisador por calcinação. Os catalisadores testados foram ácidos inorgânicos nanoporosos, cristalinos ou amorfos, com tamanho de partícula nano ou micrométrico, especificamente silicoaluminofosfatos, aluminossilicatos e óxidos mistos de zircónio e tungsténio. Estes tipos de materiais são versáteis uma vez que as suas propriedades físicoquímicas podem ser modificadas no sentido de melhorar os seus desempenhos catalíticos na conversão de diferentes tipos de substratos (ex. através da criação de mesoporos nos materiais e/ou modificação das propriedades ácidas). Os materiais testados exibiram melhores desempenhos catalíticos para a conversão de pentoses em Fur do que para a de hexoses em Hmf, quando o solvente era a água. Em suma, os catalisadores apresentaram boa estabilidade hidrotérmica. No caso dos sistemas reacionais à base de líquidos iónicos foram verificados elevados rendimentos em Fur e Hmf. especialmente quando os substratos eram a D-frutose ou polissacarídeos relacionados. Contudo, os catalisadores sofreram desativação tal que as reações catalíticas ocorreram em fase homogénea. Conforme explicado numa revisão bibliográfica sobre o estado da arte da conversão catalítica de carboidratos em Fur e Hmf usando líquidos iónicos, o desenvolvimento de sistemas catalíticos heterogéneos à base de líquidos iónicos representa um grande desafio.
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Kitpaosong, Chaisiri. "Amélioration agronomique et post-recolte de la production d'acide Furanique F2 (FuFA-F2) extrait du latex d'Hevea brasiliensis". Electronic Thesis or Diss., Université de Montpellier (2022-....), 2024. http://www.theses.fr/2024UMONG029.
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Le latex d'Hevea brasiliensis qui contient de grosses quantités de poly(cis-1,4-isoprene) plus communément appelé caoutchouc naturel, est une matière première essentielle pour la production de nombreux produits nécessitant de l'élasticité et provenant de sources naturelles. Le latex se compose de divers autres composants, dont des lipides (~1,3 % en poids du latex frais), avec des variations selon les génotypes. Dans certains génotypes, des lipides contenant une structure furanique peuvent être présents. Ces acides gras furaniques (FuFA) possèdent des propriétés telles que des effets antioxydants, anti-inflammatoires, avec une activité bénéfique sur la prévention des maladies cardiaques, l’amélioration de la masse musculaire, ou encore la prévention des désordres métaboliques. Ces propriétés sont importantes pour améliorer la qualité de vie, ce qui indique un potentiel de découverte de nouveaux produits de haute valeur à partir du latex d'Hevea brasiliensis. Dans cette thèse, 52 génotypes de caoutchouc ont été examinés dans des essais de clones à petite échelle au Cambodge pour évaluer la varialbilité génétique de la concentration de FuFA dans le latex. Les génotypes dont la parenté incluait le clone PB5/51 ont montré un plus haut potentiel de production de FuFA. La quantité de FuFA trouvée était positivement corrélée avec la teneur en acide gras C16:1. La plus forte concentration de FuFA dans le latex frais a été trouvée dans le génotype IRCA 323 (0.71% p/p latex) tandis que la plus grosse production par saignée provient du génotype PB235 (2446 mg/arbre/saignée). Par ailleurs, dans un autre essai agronomique en station experimentale en Thailande, l'influence de trois facteurs agronomiques sur le métabolisme de biosynthese du polyisoprene du latex (évalué par le “diagnostic latex”) et sur la production de FuFA a été étudiée : Saison (échantillons mensuels sur deux années agronomiques) , Systèmes de saignée (S/2 d2, S/3 2d3, et S/2 d3 avec stimulation) et Génotypes (PB235, RRIM600, et RRIT251). Comme prévu, le génotype a été le principal facteur influençant la production de FuFA, le PB235 fournissant de loin la plus grande quantité de FuFA. Le système de saignée n'a eu qu’un effet limité sur le métabolisme du latex et la production de FuFA. La principale variation saisonnière a été une augmentation du rendement en latex tout au long de l'année agronomique, accompagnée d'une hausse du rendement en FuFA. Aucune corrélation n’a été observée entre le métabolisme de la régénération du polyisoprene du latex et la quantité de FuFA. Des stratégies d'extraction et de purification du FuFA ont été étudiées en utilisant le latex PB235 stabilisé à l'ammoniaque. Il a été trouvé que l'extraction utilisant l'acétate d'éthyle avait un potentiel comparable à celui du chloroforme-méthanol pour extraire le FuFA. L'utilisation d’une silice 60A comme phase stationnaire semble être la plus efficace pour séparer chromatographiquement sur colonne les FuFA sous forme de triglycérides (TG-FuFA) des autres lipides présents dans le latex. De plus, la possibilité d’utiliser des enzymes lipolytiques, telles que GPLRP2 et cutinase, pour hydrolyser les lipides contenant du FuFA et potentiellement récupérer le FuFA sous forme d'acides gras libres à partir du latex stabilisé a été démontrée. L'analyse structurelle des TG-FuFA par des techniques de RMN a confirmé la structure du FuFA-F2 (9M5). L'analyse thermique des TG-FuFA par analyse thermogravimétrique sous azote a montré des changements de poids à 420 °C, tandis qu’en présence d'oxygène, des changements de poids se sont produits entre 200-360 °C et 370-530 °C. Ces résultats de recherche indiquent la possibilité de développer des génotypes d’hevea avec une teneur plus élevée en FuFA, confirment l'utilisation de solvants naturels pour l'extraction du FuFA, et présentent des voies de purification du FuFA à l'aide de techniques chromatographiques ou par une approche enzymatiqueHevea latex that contains high amount of poly(cis-1,4-isoprene), commonly know as natural rubber, is an essential raw material for producing many products that require elasticity and come from natural sources. The latex consists of various other components, including lipid (~1.3% by weight of fresh latex), with variations depending on the genotypes. In some genotypes, lipids containing a furan structure can be found. These furan fatty acids (FuFA) possess properties such as antioxidation and anti-inflammatory effects, with beneficial activity in preventing heart diseases, improving muscle mass, and preventing metabolic disorders. These properties are important for improving the quality of life, highlighting the potential of Hevea latex for implementing new high-value by-products. In this thesis, 52 rubber genotypes from a small-scale clone trials in Cambodia were studied to assess the genetic variability of the concentration of FuFA in latex. Genotypes related to the PB5/51 rubber strain were found to have the potential to produce FuFA, and the amount of FuFA found was positively correlated with the C16:1 fatty acid content. The highest FuFA concentration in fresh latex was found in IRCA323 clone (0.71 % w/w latex) and the highest production per tapping was from PB235 genotype (2446 mg/tree/tapping). Moreover, in another experimental trial in Thailand, the influence 3 agronomical factors on the latex cell rubber metabolism (assessed by “Latex diagnosis”), and FuFA production was studied: season (monthly samplings on 2 agronomical years), tapping systems (S/2 d2, S/3 2d3, S/2 d3 with stimulation) and genotype (PB235, RRIM600, and RRIT251). As expected, genotype was the main factor influencing FuFA production, with PB235 yielding a high quantity of FuFA. The tapping system had minimal effect on latex cell rubber metabolism and FuFA production. The primary seasonal variation was an increase in latex yield throughout the agronomical year, accompanied by a rise in FuFA yield. No correlation was observed between latex cell rubber metabolism and FuFA content. Extraction and purification strategies for FuFA were investigated using PB235 latex stablized with ammonia. It was found that extraction using ethyl acetate had comparable potential to chloroform-methanol in extracting FuFA. Using silica 60A as the stationary phase appears to be the most effective method for column chromatography to separate FuFA in the form of triglycerides (TG-FuFA) from other lipids found in latex. Moreover, the use of lipolytic enzymes such as GPLRP2 and cutinase for hydrolyzing FuFA-containing lipids and potentially recover FuFA as free fatty acids from stabilized latex was demonstrated. The structural analysis of TG-FuFA using NMR techniques confirmed the FuFA-F2 (9M5) structure. Thermal analysis of TG-FuFA using TGA under nitrogen conditions showed weight changes at 420°C, while under air conditions, weight changes occurred between 200-360°C and 370-530°C. The research findings indicate the possibility of developing rubber genotypes with higher FuFA content, identifying natural solvents suitable for FuFA extraction, and presenting the feasibility of FuFA purification through chromatography or enzymatic techniques
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Smith, Andrew W. T. "On the synthesis of furans and furan fatty acids". Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/46353/.
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This thesis describes the use of silver nitrate and iodine to promote 5-endo-dig cyclisations in the synthesis of furans. The oxidation of furylethanols will be discussed as will methods to synthesise furylacetic acids. The total synthesis of a natural product, Plakorsin B will be described along with the total synthesis of the furan fatty acids F5 and F6 as well as giving an overview of their proposed role in Nature. Finally, a new methodology for methylation of halogenated heterocycles will be discussed.
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Lee, Robert J. "A biosynthetically-inspired synthetic route to substituted furans and its application to the total synthesis of the furan fatty acid F5". Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/36252.
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Dietary fish oil supplementation has long been shown to have significant health benefits, largely stemming from the anti-inflammatory activity of the ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) present in fish oils. The anti-inflammatory properties of these fatty acids has been linked to beneficial health effects, such as protecting the heart, in individuals consuming diets rich in fish, or supplemented with fish oils. These effects are highly notable in the Māori people native to coastal regions of New Zealand; the significantly lower rates of heart problems compared to the inland populous has been attributed to the consumption of the green lipped mussel Perna Canaliculus. Commercially available health supplements based on the New Zealand green lipped mussel include a freeze-dried powder and a lipid extract (Lyprinol®), the latter of which has shown anti-inflammatory properties comparable to classical non-steroidal anti-inflammatory drugs (NSAIDs) such as Naproxen. GCMS analysis of Lyprinol by Murphy et al. showed the presence of a class of ω-4 and ω-6 PUFAs bearing a highly electron rich tri- or tetra-alkyl furan ring, which were designated furan fatty acids (F-acids). Due to their instability, isolation of F-acids from natural sources cannot be carried out and a general synthetic route toward this class of natural products was required. To accomplish this, the biosynthesis of F-acids was mimicked by utilising an oxidation of 1,3-dienes, followed by a dehydration/aromatisation to generate the heterocyclic furan ring. Singlet oxygen was chosen as the means of oxidising the conjugated dienes giving endoperoxides. To mimic the biological aromatisation of the peroxide intermediates the Appel reagent was chosen and, in a novel application of the reagent, was exploited as a mild, metal free method of dehydrating the cyclic peroxides to their corresponding furans. The biomimetic furan synthesis was applied toward a selection of 1,3-diene substrates bearing a range of pre-installed functionalities and substitution patterns including alkyl, aryl, alkenes, cyclopropyl rings, silyl ethers, and esters, alongside being applied to the total synthesis of the furan fatty acid F5. A brief exploration of the possibility of performing the aromatisation reaction under catalytic conditions was carried out, to determine whether endoperoxides could be converted to furans without needing a stoichiometric quantity of Appel reagent, by harnessing a catalytic quantity of triphenylphosphine oxide and regenerating the active P(V) species via reaction with oxalyl chloride. Furthermore, an optimisation study was carried out using a simple design of experiments procedure to ascertain the ideal conditions for carrying out the Appel-type dehydration of endoperoxides. Finally, the scope of the reaction sequence was expanded to be performed in a continuous flow reactor, with telescoping of the singlet oxygen diene oxidation and Appel-type aromatisation to increase oxidation yields and to omit the requirement for isolation of peroxide intermediates, and was applied to the synthesis of a selection of 2,5-diaryl furan motifs.
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Brotherton, Clare. "Synthesis and oxidation of tricyclic steroid analogues". Thesis, University of Aberdeen, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362235.
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The subject of this thesis is the synthesis and oxidation of tricyclic steroid analogues. The synthesis of the tricyclic derivatives, 1,2-dihydro-5-hydroxy-3H-benz[e]inden-3-ones, is described in chapter 1. The synthetic route involves the initial condensation of readily available acetophenone precursors with furfuraldehyde. Subsequent acidic hydrolysis of the resulting furanyl compounds afforded a diketo acid and/or furan acid depending on the nature and position of the substituent on the aromatic ring. Intramolecular condensation of the diketo acids provides a versatile intermediate in the cyclopentene acetic acid derivatives, the hydrogenation and alkylation of which is discussed in chapter 2. Cyclisation of the acetic acid derivatives with acetic anhydride and subsequent deacetylation provided the tricyclic phenolic compounds. The introduction of angular methyl groups in the cyclopentene acetic acid derivatives is discussed in chapter 2. Reductive methylation of these compounds using lithium in liquid ammonia failed, therefore, hydrogenation, followed by direct alkylation was investigated. Hydrogenation of the esters of the cyclopentene acetic acids gave a mixture of the desired reduced compounds along with the super hydrogenated cyclopentane derivatives. It has been shown that hydrogenation of such systems gives rise to two products, namely the trans cyclopentanone and the cis cyclopentane, the trans cyclopentanone arising through 1,4 addition. Permethylation of these cyclopentanones was achieved using KH, NaH and tBuOK. Chapter 3 deals with the oxidation of the phenols prepared in chapter 1 and the trimethyl compounds prepared in chapter 2. A short review on the oxidation of phenols forms the introduction. The oxidation of the tricyclic compound, 1,2-dihydro-5-hydroxy-3H-benz[e]inden-3-one, using a variety of different oxidising agents did not lead to quinone formation, however phenolic coupling was observed to give a biphenol. Oxidation of the permethylated compounds prepared in chapter 2 with DDQ gave the expected dehydrogenation products via a quinone methide intermediate.
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黃嘉寶 e Ka-po Wong. "Derivatives of 2,5-disubstituted C18 furanoid fatty esters". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1991. http://hub.hku.hk/bib/B31210041.
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Wang, Yamin. "Novel synthetic routes to furan fatty acids and their analogues". Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23486.
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Furan and its derivatives are commonly found in numerous compounds such as natural products, polymers and medicines. The furan ring system is not only the core component to many natural products, but also serves as a key synthetic intermediate to access other more complex molecules. Among furan derivatives, furan fatty acids (F-acids) are an important class of natural products which are widely distributed in nature, and occupy a unique place in the field of medicinal chemistry because of their potent biological and pharmacological activity. This thesis examines the development of novel approaches towards highly substituted furans, with the ultimate goal of applying novel and high efficiency methods to the synthesis of F-acids and their derivatives. The first total synthesis of a natural product, an F-acids metabolite originally isolated from shark (Lamna ditropis) bile, was accomplished by the utilisation of an iodocyclisation of the corresponding 3-alkyne-1,2-diol to construct the furan nucleus; the synthetic route will be discussed in this thesis. Through the study of palladium-catalysis of a formal cyclisation to construct the furan ring system, a general route to access different F-acids has been developed. Splitting the F-acids into relatively simple fragments allows for easy preparation and modification of two fragments to produce a range of F-acids. The synthetic route was then applied to the formal synthesis of a natural product, F-acid F6. After optimisation of the synthetic route, total synthesis of F-acids F4, F6 and their analogues was accomplished.
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Ait, Rass Hicham. "Transformation chimique du furfural en acide 2,5-furane dicarboxylique par catalyse hétérogène". Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10198/document.
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Ces travaux de thèse portent sur la conversion par catalyse hétérogène du furfural (produit biosourcé produit, par déshydratation du xylose issu de l'hydrolyse acide de l'hémicellulose) en acide 2,5-furane dicarboxylique (FDCA, substituant potentiel de l'acide téréphtalique, monomère de polyesters et polyamides, issu du pétrole). Cette transformation a été envisagée en deux étapes catalytiques: 1) l'hydroxyméthylation du furfural en 5-hydroxyméthylfurfural (HMF) par le formaldéhyde aqueux ou le trioxane en présence d'un catalyseur acide. Les rendements maxima de 40% ont été obtenus en utilisant le formaldéhyde aqueux en présence de nanoparticules de ZSM-5. L'instabilité du furfural et du HMF dans ces conditions réactionnelles est la principale difficulté. 2) l'oxydation aérobie du HMF en FDCA. En milieu alcalin faible (Na2CO3), en présence d'un catalyseur Pt/C promu par le Bi (rapport molaire Bi/Pt = 0,2) à 100 °C et sous 40 bar d'air, le FDCA est obtenu avec un rendement quantitatif. La modification du Pt par le bismuth permet de limiter la lixiviation du Pt dans le milieu réactionnel et de recycler le catalyseur sans prétraitement préalable et sans perte significative de l'activité, comme démontré ensuite en réacteur continuThis thesis reports a study of heterogeneously catalyzed conversion of furfural (biobased product formed from the acid-catalyzed dehydration of xylose) into 2,5-furane dicarboxylique acid (FDCA, possible replacement monomer for terephtalic acid for the production of polyethylene terephtalate). This transformation has been considered in two catalytic steps: 1) hydroxymethylation of furfural with aqueous formaldehyde or trioxane into 5-hydroxymethylfurfural (HMF) in the presence of solid acids. The maximum yields of 40% have been obtained using aqueous formaldehyde in the presence of nanoparticles of ZSM-5. The main problem was the lack of stability of furfural and HMF in reaction conditions. 2) aerobic oxidation of HMF into FDCA. HMF was oxidized in alkaline aqueous solutions over Pt-based catalysts using dioxygen from air. Promotion of the catalyst with bismuth and the presence of a weak base (Na2CO3) yielded a catalytic system with a remarkable activity and selectivity. HMF was completely and exclusively converted to FDCA within 2,5 h. The catalyst could be recovered by simple filtration and reused several times without significant loss of activity and with no platinum or bismuth leaching
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Costigan, Michael Gerard. "Synthesis and investigation of a furan dicarboxylic acid which accumulates in uraemia". Thesis, University of Liverpool, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359189.
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Ayoub, Nadim. "Synthèse et valorisation des dérivés furaniques issus de la biomasse par oxydations sélectives". Electronic Thesis or Diss., Compiègne, 2022. http://www.theses.fr/2022COMP2677.
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La biomasse fait partie des ressources renouvelables qui peuvent répondre durablement à nos besoins de production de carburants, de produits chimiques et de matériaux. En effet, la biomasse non comestible telle que la lignocellulose a attiré l'attention des chercheurs et des scientifiques au cours des dernières décennies en tant qu'alternative renouvelable. Le furfural et le 5-hydroxyméthylfurfural (HMF), dérivés de la déshydratation des pentoses et des hexoses respectivement, sont produits à plusieurs millions de tonnes par an. Ces derniers composés sont donc des molécules plateformes et représentent un intérêt majeur dans le cadre du développement durable. Ce travail vise à explorer des méthodes nouvelles et vertes pour l'oxydation sélective du furfural et de HMF afin de produire des produits biosourcés à haute valeur ajoutée tels que le 2,5-diformylfurane (DFF), l'acide maléique et l'acide succinique. Tout d'abord, un système alternatif d'oxydation de HMF a été présenté, sans l'utilisation de catalyseurs de métaux nobles, de hautes pressions et évitant la production de déchets toxiques. Dans ce contexte, l'oxydation à l'échelle du gramme de HMF conduit à la formation de DFF. Cette réaction a été catalysée par l'acide 2-iodobenzènesulfonique en présence d'Oxone®. Dans des conditions expérimentales optimisées, la conversion du HMF s'est avérée être de 100%, tandis que le rendement et la sélectivité du DFF étaient vers 90%. Par la suite, nous avons démontré un processus sans catalyseur pour la synthèse à l'échelle du gramme de l'acide maléique à partir de furfural en utilisant des irradiations ultrasonores à hautes fréquences. Une sélectivité de 70% en acide maléique avec 92% de conversion du furfural a été obtenue sans aucun catalyseur dans des conditions douces en utilisant H2O2 comme oxydant. Notre approche alternative permet l'utilisation de la biomasse au lieu du pétrole pour synthétiser l'acide maléique à partir du furfural dans un processus écologique et économe en énergie. Enfin, un nouveau procédé catalytique est développé en utilisant des nanoparticules de magnétite, comme catalyseur métallique bon marché et non noble, et du peroxyde d'hydrogène pour l'oxydation du furfural en acide succinique. La conversion totale du furfural a été obtenue avec 67% de rendement en acide succinique dans des conditions doucesBiomass is one of the renewable and green resources that can sustainably meet our needs for the production of fuels, chemicals and materials. Indeed, nonedible biomass such as lignocellulose has attracted attention of researchers and scientists in the last decades as a renewable alternative. Furfural and 5-hydroxymethylfurfural (HMF), derived from the dehydration of pentoses and hexoses respectively, are produced in multimillion ton-scale annually. The latter compounds are, therefore, platform molecules and represent a major interest in the context of sustainable development. This work aims to explore novel and green methods for the selective oxidation of furfural and HMF to produce high value-added bio-sourced products such as, 2,5-diformylfuran (DFF), maleic acid and succinic acid. First, an alternative system of HMF oxidation was presented, without the use of noble metal catalysts, high pressures and avoiding the production of toxic wastes. In this context, the gram-scale oxidation HMF leads to the formation of DFF. This reaction was catalyzed by 2-iodobenzenesulfonic acid in the presence of Oxone®. Under optimized experimental conditions, the HMF conversion was found to be 100%, while the DFF yield and selectivity were almost 90%. Subsequently, we demonstrated a catalyst-free process for the gram-scale synthesis of maleic acid from furfural using high frequency ultrasound irradiations. A 70% selectivity of maleic acid with 92% of furfural conversion were achieved without any catalyst under mild conditions using H2O2 as oxidant. Our alternative approach enables the use of biomass instead of petroleum to synthesize maleic acid from furfural in an eco-friendly and energy-efficient process. At last, a novel catalytic process is developed using magnetite nanoparticles, as a cheap and non-noble metal catalyst, and hydrogen peroxide for the oxidation of furfural into succinic acid. Total conversion of furfural was achieved with 67% of succinic acid yield under mild conditions
Livros sobre o assunto "Furanic acid"
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Yong, Kelvin Hin-Yeong. Intramolecular carbenoid insertions: The reactions of [alpha]-diazoketones derived from furanyl, thienyl, benzofuranyl and benzothienyl acetic acids with rhodium (II) acetate. St. Catharines, Ont: Brock University, Dept. of Chemistry, 1998.
Encontre o texto completo da fonteCapítulos de livros sobre o assunto "Furanic acid"
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Meng, Ye, Huan Liu, Jie Li e Hu Li. "Catalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid". In Catalytic Transformations of Sustainable and Versatile Furanic Chemicals, 31–57. Boca Raton: CRC Press, 2024. http://dx.doi.org/10.1201/9781003464839-3.
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Arican, Yagmur Emre. "Furan". In Food Safety, 181–94. Istanbul: Nobel Tip Kitabevleri, 2024. http://dx.doi.org/10.69860/nobel.9786053358787.13.
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Furan, a volatile compound with a strong etheric odor and flammability, is a crucial component in the industrial context, producing various chemicals such as pyrrole, thiophene, tetrahydrofuran, pharmaceuticals, and pesticides. It is also used as a solvent for resins in organic synthesis and is present in many foods, including carbohydrates, unsaturated fatty acids, carotenoids, vitamin C, and amino acids, due to thermal processes and high-energy radiation used in the food manufacturing industry. Furan and its derivatives are utilized in the refining of tobacco and as flavoring agents in specific products. Furan can be generated and emitted into the environment due to human activities like combustion, fire, exhaust, and cigarette smoke. When heated, it enhances oxidative processes in lipids and proteins, impacting free radicals and antioxidant defense. Furan is a toxic substance that can cause skin irritation, burns, headaches, dizziness, shortness of breath, and loss of consciousness. Its vapor is narcotic and acts as a central nervous system depressant, leading to pulmonary edema and potentially death. Both acute oral or dermal exposure and chronic exposure are linked to significant toxicity. Furan is present in both professionally produced and handmade meals, contributing to their taste. In adults, susceptibility to furan exposure is due to coffee, while grains are considered the largest contributor to furan exposure in children and adolescents. High concentrations of furans are found in roasted coffee, heat-treated foods, and crispy and dry products like toast or bread crusts. Health institutions are apprehensive about furan’s deleterious characteristics, as studies conducted on rodents have demonstrated its toxicity primarily impacts the liver.
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Gundekari, Sreedhar, Rajathsing Kalusulingam, Bhavesh Dakhara, Mariappan Mani, Joyee Mitra e Kannan Srinivasan. "Levulinic Acid- and Furan-Based Multifunctional Materials: Opportunities and Challenges". In Catalysis for Clean Energy and Environmental Sustainability, 291–343. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-65017-9_11.
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Moore, J. A., e William W. Bunting. "Polyesters and Polyamides Containing Isomeric Furan Dicarboxylic Acids". In Advances in Polymer Synthesis, 51–91. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4613-2121-7_3.
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Winkelmann, Jochen. "Diffusion coefficient of tribenzo[aci]phenazine in tetrahydro-furan-d8". In Diffusion in Gases, Liquids and Electrolytes, 1198. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-540-73735-3_974.
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Winkelmann, Jochen. "Diffusion coefficient of tribenzo[aci]phenazine ion(2-) in tetrahydro-furan-d8". In Diffusion in Gases, Liquids and Electrolytes, 1199. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-540-73735-3_975.
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Maier, M. E. "Butenolides from Furans". In Three Carbon-Heteroatom Bonds: Acid Halides; Carboxylic Acids and Acid Salts, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-020-01413.
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Masse, C. E. "From Furan". In Three Carbon-Heteroatom Bonds: Acid Halides; Carboxylic Acids and Acid Salts, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-020-00269.
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Subramanian, L. R. "From Substituted Benzo[]furan". In Three Carbon-Heteroatom Bonds: Acid Halides; Carboxylic Acids and Acid Salts, 1. Georg Thieme Verlag KG, 2007. http://dx.doi.org/10.1055/sos-sd-020-00862.
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Singh, Sonia, Nitin Agrawal e Isha Mishra. "Pharmacology and Phytochemistry of Coriander". In Ethnopharmacological Investigation of Indian Spices, 173–96. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-2524-1.ch014.
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Coriander, named as Coriandrum sativum Linn, belongs to the family Umbelliferae and is one of the most popular and well-known spices/condiments and herbal medicines. The essential oils and fatty oils are the two major active chemical constituents present in the plant. The other minor ingredients found to be present are monoterpenes hydrocarbons i-e limonene, γ-terpinene, α-pinene, p-cymene, borneol, citronellol, camphor, geraniol, and geraniol acetate and abd heterocyclic components such as pyrazine, pyridine, thiazole, furan and tetrahudrofuran derivatives, isocoumarins, coriandrin, dihydrocoriandrin, coriandrons A-E, flavonoids. The volatile oil from the leaf contains aromatic acids such as 2-decenoic acid, E-11-tetradecenoic acid, undecyl alcohol, tridecanoic acid, capric acid, undecanoic acid, and more. The current pharmacological research reveals the application of coriander has antibacterial and antifungal activity.
Trabalhos de conferências sobre o assunto "Furanic acid"
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De Oliveira Vigier, Karine, Christophe Coutanceau e Steve Baranton. "Electro-oxidation of glycerol and diglycerol in the presence of Pt or Pd-based electrocatalyst follows by the reductive amination of the products obtained". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/olba8004.
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The selective electro-oxidation of bio-based organic molecules such as glycerol, polyglycerols, saccharides and furanic compounds has received particular attention in recent years, due to the high value-added compounds that result and their numerous industrial applications. Electrochemical methods are therefore well suited for the controlled oxidation of small organic molecules in aqueous media. Glycerol valorization through partial oxidation is a good way of obtaining many different molecules with high added value such as glyceric acid, tartronic acid, dihydroxyacetone, glyceraldehyde etc., that can find various applications in different domains such as organic chemistry, medical, and cosmetic industries. Here we have studied the electro-oxidation of glycerol in the presence of Pt or Pd-based catalysts. The development of mono- and bimetallic catalysts based on platinum on the one hand and palladium on the other hand for the electro-oxidation of glycerol is a very important goal to direct the reaction pathways to desired products.            Bimetallic catalysts synthesized by the water-in-oil microemulsion method were characterized by physicochemical (TEM, XRD, ATG, SAA and ICP-OES) and electrochemical (active surface and surface composition study) methods in order to obtain a correlation between surface structure and electrochemical response. The reactivity of glycerol and diglycerol in alkaline medium was evaluated to determine the catalyst offering the best conversion. A selectivity study of these catalysts was performed by in situ infrared spectroscopy to determine the reaction intermediates. The distribution of reaction products was determined by HPLC analysis and 1H and 13C NMR analyses.
           Reductive amination reactions with ammonia on the one hand and n-butylamine on the other hand on products identified as being of interest (glyceraldehyde/dihydroxyacetone) were carried out in the presence of hydrogen and catalyzed by palladium-based nanoparticles dispersed on carbon.
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Watanabe, Kenshi, Miho Nishijima, Shinzo Mayuzumi e Tsunehiro Aki. "Utilization of sugar cane bagasse as a substrate for fatty acid production by Aurantiochytrium sp." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/bptz2428.
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The genus Aurantiochytrium, a heterotrophic marine protist, produces significant amounts of polyunsaturated fatty acids and carotenoids and is promising as an alternative source of those lipids. This research aimed to utilize lignocellulosic biomass, which is abundant on land and does not compete with food supply, for fatty acid production by Aurantiochytrium limacinum strain SR21. Sugarcane bagasse soaked in diluted sulfuric acid was blasted by steam explosion and subsequently saccharified by the enzyme. When SR21 was cultivated in the medium containing saccharified liquid of sugarcane bagasse, the cell growth was almost abolished as compared with the control medium with the same glucose concentration, suggesting the presence of growth-inhibiting components in the saccharified liquid. The growth and fatty acid production of SR21 was significantly inhibited in the presence of furans and phenolic compounds previously reported to be generated by heat treatment of lignocellulosic biomass. Among them, furfural was detected in the bagasse saccharified liquid at the concentration that could inhibit the growth of SR21. Removal of such compounds by activated charcoal restored the cell growth and fatty acid productivity.
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Stevens, Kristof, Marieke Op de Beeck, Sara Figaroli e Annemieke Madder. "Synthesis and cross-linking of new furan nucleic acids". In XIVth Symposium on Chemistry of Nucleic Acid Components. Prague: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 2008. http://dx.doi.org/10.1135/css200810210.
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KEMPPAINEN, JOSH, IVAN GALLEGOS, PRATHAMESH DESHPANDE, JACOB GISSINGER e GREGORY ODEGARD. "MOLECULAR DYNAMICS SIMULATIONS OF FURAN RESIN (POLYFURFURYL ALCOHOL): PREDICTING MECHANICAL PROPERTIES". In Thirty-sixth Technical Conference. Destech Publications, Inc., 2021. http://dx.doi.org/10.12783/asc36/35847.
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Furan resins can be used as precursor resin for Carbon-Carbon Composites but has also been used in adhesives, acid/corrosion resistant materials, and as an alternative fuel precursor [15]. This paper contains the most current understanding of the structure of furan resin and a Molecular Dynamics workflow for computationally simulating its polymerization with the 'fix bond/react' command implemented in LAMMPS. The predicted mechanical properties of the polymerized resin are in good agreement with the literature values.
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Bárta, Jan, e Michal Hocek. "Modular synthesis of 5-substituted thiophene and furan C-nucleosides and their analogues". In XVth Symposium on Chemistry of Nucleic Acid Components. Prague: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 2011. http://dx.doi.org/10.1135/css201112300.
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Müller, Franziska, Walter Vetter e Melanie Hogg. "Furan fatty acid profiles provide insights into quality of soy products". In Virtual 2021 AOCS Annual Meeting & Expo. American Oil Chemists’ Society (AOCS), 2021. http://dx.doi.org/10.21748/am21.565.
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Op de Beeck, Marieke, Ellen Gyssels, Diederica Claeys e Annemieke Madder. "New inducible nucleic acid cross-linking methodology based on oxidation of incorporated furan moieties: scope and limitations". In XVth Symposium on Chemistry of Nucleic Acid Components. Prague: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 2011. http://dx.doi.org/10.1135/css201112282.
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Carrette, L. L. G., E. Gyssels, N. Delaet, J. Loncke e A. Madder. "Furan oxidation cross-linking: a versatile approach for the study and targeting of protein and nucleic acid interactions". In XVIth Symposium on Chemistry of Nucleic Acid Components. Prague: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 2014. http://dx.doi.org/10.1135/css201414178.
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Aguiar, Antônio S. N., Jaqueline E. Queiroz, Pollyana P. Firmino, Wesley F. Vaz, Ademir J. Camargo, Gilberto L. B. de Aquino, Hamilton B. Napolitano e Solemar S. Oliveira. "Experimental and theoretical study of the chalcone molecule (E)-3-(2,6-difluorophenyl)-1-(furan-2-yl)-prop-2-en-1-one". In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202033.
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In this work, we synthesized chalcone (E)-3-(2,6-difluorophenyl)-1-(furan-2-yl)-prop-2-en-1-one (DTP) via Claisen-Schmidt condensation. The supramolecular arrangement of the obtained compound was characterized by X-ray diffraction and Hirshfeld surface, and its crystalline structure was determined. The DTP molecule was studied using the Density Functional Theory, at the theoretical level M06-2X/6-311G ++G, in order to obtain information about its structural and electronic properties. A map of molecular electrostatic potential was obtained to predict the types of interactions and their acid-base behavior.
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Tadjarodi, Azadeh, e Saeedeh Eslami Nezhad. "Solvent-free synthesis of Thiocarbamic acid [(furan-2-yl) ethylidene] hydrazide under ball-milling conditions". In The 13th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2009. http://dx.doi.org/10.3390/ecsoc-13-00186.
Texto completo da fonteRelatórios de organizações sobre o assunto "Furanic acid"
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Word, J. Q., J. A. Ward e A. L. Squires. Results of chemical, toxicological, and bioaccumulation evaluations of dioxins, furans, and guaicol/organic acids in sediments from the Grays Harbor/Chehalis River area. Office of Scientific and Technical Information (OSTI), setembro de 1990. http://dx.doi.org/10.2172/6364326.
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Rouseff, Russell L., e Michael Naim. Characterization of Unidentified Potent Flavor Changes during Processing and Storage of Orange and Grapefruit Juices. United States Department of Agriculture, setembro de 2002. http://dx.doi.org/10.32747/2002.7585191.bard.
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Citrus juice flavor quality traditionally diminishes after thermal processing and continuously during storage. Our prior studies found that four of the five most potent off-aromas formed during orange juice storage had not been identified. The primary emphasis of this project was to characterize and identify those potent flavor degrading aroma volatiles so that methods to control them could be developed and final flavor quality improved. Our original objectives included: 1 Isolate and characterize the most important unidentified aroma impact compounds formed or lost during pasteurization and storage. 2. Determination of thiamine and carotenoid thermal decomposition and Strecker degradation pathways in model solutions as possible precursors for the unidentified off-flavors. 3. Evaluate the effectiveness of an "electronic nose" to differentiate the headspace aromas of from untreated and heat pasteurized orange and grapefruit juices. 4. Use model systems of citrus juices to investigate the three possible precursor pathways (from 2) for flavor impact compounds formed or lost during pasteurization or storage. RESULTS - The components responsible for citrus storage off flavors and their putative precursors have now been identified. Certain carotenoids (b-carotene) can thermally degrade to produce b-ionone and b-damascenone which are floral and tobacco smelling respectively. Our GC-O and sensory experiments indicated that b-damascenone is a potential storage off-flavor in orange juice. Thiamine (Vitamin B1) degradation produces 2-methyl-3-furan thiol, MFT, and its dimer bis(2- methyl-3-furyl) disulfide which both produce meaty, savory aromas. GC-O and sensory studies indicated that MFT is another storage off-flavor. Methional (potato aroma) is another off flavor produced primarily from the reaction of the native amino acid, methionine, and oxidized ascorbic acid (vitamin C). This is a newly discovered pathway for the production of methional and is more dominant in juices than the classic Maillard reaction. These newly identified off flavors diminish the flavor quality of citrus juices as they distort the flavor balance and introduce non-typical aromas to the juice flavor profile. In addition, we have demonstrated that some of the poor flavor quality citrus juice found in the market place is not only from the production of these and other off flavors but also due to the absence of desirable flavor components including several potent aldehydes and a few esters. The absence of these compounds appears to be due to incomplete flavor volatile restoration after the making of juice concentrates. We are the first to demonstrate that not all flavor volatiles are removed along with water in the production of juice concentrate. In the case of grapefruit juice we have documented which flavor volatiles are completely removed, which are partially removed and which actually increase because of the thermal process. Since more that half of all citrus juices is made into concentrate, this information will allow producers to more accurately restore the original flavor components and produce a juice with a more natural flavor. IMPLICATIONS - We have shown that the aroma of citrus juices is controlled by only 1-2% of the total volatiles. The vast majority of other volatiles have little to no direct aroma activity. The critical volatiles have now been identified. The ability to produce high quality citrus juices requires that manufacturers know which chemical components control aroma and flavor. In addition to identifying the critical flavor components (both positive and negative), we have also identified several precursors. The behavior of these key aroma compounds and their precursors during common manufacturing and storage conditions has been documented so manufacturers in Israel and the US can alter production practices to minimize the negative ones and maximize the positive ones.