Trifluoromethanesulfonic Acid as Acylation Catalyst: Special Feature for C- and-or O-Acylation Reactions. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.

The aim of the present study was to investigate the postprandial effect of diet composition on circulating acylated ghrelin levels in healthy women. A randomized cross-over study of three experimental treatments was performed. A total of 11 healthy young women of normal body weight completed the study. All 11 subjects consumed three iso-energetic meals of different macronutrient composition, a balanced meal (50% carbohydrates, 30% fat and 20% protein), a high-fat meal (45% carbohydrates, 45% fat and 10% protein) and a high-protein meal (45% carbohydrates, 20% fat and 35% protein), for breakfast on separate days. The test meals were administered 1 month apart. Blood samples were withdrawn immediately before and at 15, 30, 60, 120 and 180 min after the test meal for measurement of plasma acylated ghrelin, as well as serum glucose, insulin and triacylglycerol (triglyceride) levels. Acylated ghrelin fell significantly after ingestion of both the balanced and high-protein meals. Ghrelin persisted at ...

I have done a friedel crafts acylation reaction to 4-chloro phenol using benzoyl chloride. Now my reaction mixture contains o-acylated product and probably unreacted phenol. both of which contain phenolic OH group. Now how can I separate the unreacted phenol from the acylated product. I doubt whether base extraction can do it because both the components phenol and its acylated product have phenolic OH. Is there any other way such that I can remove the unreacted phenol and get the pure acylated product ...

Here the chlorobenzamide group is coupled onto the molecule before the indole-forming step, eliminating the need for carboxylate protection. The synthesis starts with (5), a β-sulfonate modified aryl hydrazine. Acylation of aryl hydrazines normally occurs preferentially at the β-nitrogen. In contrast, The sulfonate group of (5) is electron-withdrawing, reducing the nucleophilicity of the β-nitrogen and favoring acylation at the α-position [2]. The α-acyl-arylhydrazine (6) can therefore be prepared from (5) by pyridine-catalyzed acylation with 4-chlorobenzoic acid chloride. This process is mechanistically equivalent to the pyridine-catalyzed acylation of the previous synthesis. Afterward, the sulfonate is readily hydrolyzed by treatment with dilute acid ...

Vaccinia virus (VV) is a large DNA virus belonging to the Orthopoxvirus family. The viral replicative life cycle takes place solely within the cytoplasm of a mammalian host cell. The VV genome contains 196 open reading frames which are expressed in a highly regulated and temporal fashion in order to bring about the production of a mature virion. In the process of viral replication many VV proteins are synthesized that require posttranslational modifications to become functional. A few of these modifications include, glycosylation, ADP-ribosylation, phosphorylation, fatty acid acylation, and proteolytic processing. This last modification is especially important with regard to the structural proteins of the virus in that they undergo prysis for an infectious virus particle to be formed, a common theme in viral systems. In order to understand these events in more detail, three abundant virion protein constituents 4a, 4b, and 25K were chosen as models for study. The three main questions we wanted to ...

The erythrocyte Rh antigens contain an Mr = 32,000 integral protein which is thought to contribute in some way to the organization of surrounding phospholipid. To search for possible fatty acid acylation of the Rh polypeptide ...

QM:QM models, where QM is a fast molecular orbital method, offers advantages over standard quantum mechanics: molecular mechanics (QM:MM) models, especially in the description of charge transfer and mutual polarization between layers. The ONIOM QM:QM scheme also allows for reactions across the layer boundary, but the understanding of these events is limited. To explain the factors that affect cross-boundary events, a set of proton transfer processes, including the acylation reaction in serine protease, have been investigated. For reactions inside out, that is, when a group breaks a bond in the high layer and forms a new bond with a group in the low layer, QM methods that are overbinding relative to the QM method, for example, Hartree-Fock versus B3LYP, can severely overestimate the exothermicity of the reaction. This might lead to artificial reactivity across the QM:QM boundary, a phenomenon called model escape. The accuracy for reactions that occur outside in, that is, when a group in the ...

tRNA acylation levels of exponentially growing MG1655 and MG1655relA::HTF measured by northern blotting analysis. Total tRNA was extracted from cells growing in MOPS minimal medium with 0.2% glucose as the carbon source before and after isoleucine starvation. A fraction of the purified tRNA was deacylated (by 100 mM Tris-HCL [pH 9]) and charged and uncharged samples were separated by urea PAGE and transferred to a membrane. tRNAileTUV, tRNAasnUTVW and tRNAtrpT were detected by hybridization with radiolabeled tRNA-specific DNA oligonucleotide probes.

The chemoselective acylation of primary aliphatic amines has been achieved in under ten minutes (and for aromatic amines under 120 min) using vibration ball-milling, avoiding undesirable solvents which are typically employed for such reactions (e.g.DMF). Under optimised conditions, the synthesis of amides in

Aryl Narasaka acylation is realized by the catalysis of chiral rhodium complex which is in situ formed of [Rh(CO)2Cl]2 and phosphoramidite ligand. Computational studies show that the storioanl stain is about 12.58 kcal mol-1, which efficiently accelerate the C-Si bond cleavage.

Lipase-catalyzed acylation of galactosides.30 mM of aromatic galactosides were reacted with an equivalent amount of donor substrates with Novozym 435 (20 mg/mL)

Takeo Kawabata and co-workers from Kyoto University have reported in ACIE on the synthesis of multifidosides through a regioselective acylation. ACIE paper

beta-Lactamase I catalyses the hydrolysis of penicillins by an acyl-enzyme mechanism. A procedure was developed for determining the rate constants for the acylation and deacylation steps for the good substrates benzylpenicillin and phenoxymethylpenicillin; this depends on determining the fraction of enzyme that is present as acyl-enzyme in the steady state. ...

Amino Acyl Transfer RNA: Intermediates in protein biosynthesis. The compounds are formed from amino acids, ATP and transfer RNA, a reaction catalyzed by aminoacyl tRNA synthetase. They are key compounds in the genetic translation process.

CBLs determine the cellular localization of their interacting protein kinases (DAngelo et al., 2006; Xu et al., 2006; Cheong et al., 2007). The resulting CBL/CIPK complexes exert important functions at the plasma membrane by regulating the activity of ion channels and H+-ATPases (Xu et al., 2006; Fuglsang et al., 2007). The aims of this study were to investigate the potential dual lipid modification of CBL proteins by myristoylation and acylation and to unravel the influence of these lipid modifications on the functional regulation of processes decoding calcium signals. Our studies identify myristoylation and S-acylation by palmitic and stearic acids as essential modifications for calcium sensor function and report novel steps in the plasma membrane transport of acylated CBL proteins and in the membrane targeting of CBL/CIPK complexes. Importantly, our observation that the lipid modification status of the CBL protein determines the targeting of preassembled CBL/CIPK complexes provides a novel ...

Partial purification and characterization of acetyl coenzyme A: taxa-4(20),11(12)-dien-5alpha-ol O-acetyl transferase that catalyzes the first acylation step of taxol biosynthesis ...

Ghrelin, Mice, Regulation, Secretion, Insulin, Plasma, Administration, Acylation, Glucose, Cells, Mouse, Antigen, Axis, Growth Hormone, Hormone, Igf-i, Injection, Reports, Stomach, T-antigen

If I used Autobean on GWT client to serialise my POJO (sent out thro RequestBuilder) but I plan to use say, groovy, perl or php to service that request, I would need to know the serialization format of Autobean.. What is and where can I get the JSON format spec for Autobean?. ...

Švehlı́ková, Vanda, Bennett, Richard N., Mellon, Fred A., Needs, Paul W., Piacente, Sonia, Kroon, Paul A. and Bao, Yongping (2004) Isolation, identification and stability of acylated derivatives of apigenin 7-O-glucoside from chamomile (Chamomilla recutita [L.] Rauschert). Phytochemistry, 65 (16). pp. 2323-2332. ISSN 1873-3700 Full text not available from this repository. (Request a copy ...

1OLX: Roles of His291-Alpha and His146-Beta in the Reductive Acylation Reaction Catalyzed by Human Branched-Chain Alpha-Ketoacid Dehydrogenase: Refined Phosphorylation Loop Structure in the Active Site.

TY - JOUR. T1 - Serine protease acylation proceeds with a subtle re-orientation of the histidine ring at the tetrahedral intermediate. AU - Zhou, Yanzi. AU - Zhang, Yingkai. PY - 2011/2/7. Y1 - 2011/2/7. N2 - The acylation mechanism of a prototypical serine protease trypsin and its complete free energy reaction profile have been determined by Born-Oppenheimer ab initio QM/MM molecular dynamics simulations with umbrella sampling.. AB - The acylation mechanism of a prototypical serine protease trypsin and its complete free energy reaction profile have been determined by Born-Oppenheimer ab initio QM/MM molecular dynamics simulations with umbrella sampling.. UR - http://www.scopus.com/inward/record.url?scp=78751489563&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=78751489563&partnerID=8YFLogxK. U2 - 10.1039/c0cc04112b. DO - 10.1039/c0cc04112b. M3 - Article. C2 - 21116528. AN - SCOPUS:78751489563. VL - 47. SP - 1577. EP - 1579. JO - Chemical Communications. JF - Chemical ...

The mixed acylation of cellulose with fatty acids and acetic anhydride was accomplished in an excess of fatty acid, thus avoiding the addition of a toxic solvent. The experimental design enabled the parameters of a model reaction with octanoic acid to be optimized. The products contained both acetyl and octanoyl acyl groups in a 2.4/1 ratio and the maximum degree of substitution (DS) was 2.2. The use of fatty acids higher than C8 resulted in a decrease of the DS. The model reaction was applied to the esterification of four lignocellulosic wastes (LW). Their reactivity was comparable to that of cellulose when no pretreatment was used. A solvent-exchange pretreatment improved the acylation of LW by about 60%, whereas that of cellulose was increased by more than 400%. The hydrophobic character of the esterified products was confirmed.

TY - JOUR. T1 - Ureas in Organic Synthesis. XIII. Reactions of 1,3-Disubstituted Ureas with Acetic Acid Derivatives. AU - Shtrykova, Victoria Victorovna. AU - Bakibaev, A. A.. PY - 1997/4. Y1 - 1997/4. N2 - Reaction of 1,3-disubstituted ureas with the derivatives of acetic acid yields depending on the substrate structure and process conditions either acetamides or N-acetylureas. Addition of urea inhibits N-acylation.. AB - Reaction of 1,3-disubstituted ureas with the derivatives of acetic acid yields depending on the substrate structure and process conditions either acetamides or N-acetylureas. Addition of urea inhibits N-acylation.. UR - http://www.scopus.com/inward/record.url?scp=0031328205&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0031328205&partnerID=8YFLogxK. M3 - Article. AN - SCOPUS:0031328205. VL - 33. SP - 460. EP - 463. JO - Russian Journal of Organic Chemistry. JF - Russian Journal of Organic Chemistry. SN - 1070-4280. IS - 4. ER - ...

Polysaccharide esters (cellulose and starch) are among the first polymeric materials applied commercially. The way of producing these technically relevant derivatives, mainly the carboxylic acid esters of C2 to C4 acids, have not been changed significantly during their history of manufacture. The investigation of new acylation methods and strategies of analysis was revived during the last decade by the search for tailored, biocompatible, material for specific fields of application, e.g., biotechnology, sensor technique and medicine. Unconventional solvents were developed for completely homo-geneous acylation reaction applying state of the art techniques of modern organic chemistry for polysaccharide modification. This book will provide a first comprehensive summary of acylation methods in a very practical manner. Detailed structure analysis is indispensable for the evaluation of structure-property-relationships. Spectroscopic methods in particular FTIR- and NMR spectroscopy including two ...

Ceramide, a key intermediate in sphingolipid metabolism, is synthesized by acylation of sphinganine followed by dehydrogenation of dihydroceramide to ceramide. Using radioactive sphinganine, we have examined the site and topology of dihydroceramide synthesis in well-characterized subcellular fractions from rat liver. [4,5-3H]Sphinganine was introduced as a complex with BSA and was metabolized to [4,5-3H]dihydroceramide upon incubation of rat liver homogenates or microsomes with fatty acyl CoA. Conditions were established in a detergent-free system in which dihydroceramide synthesis was not limited by either substrate availability or by amounts of microsomal protein or reaction time. The distribution of dihydroceramide synthesis was found to exactly parallel that of an endoplasmic reticulum (ER) marker upon subfractionation of microsomes, and no endogenous activity was detected in either purified Golgi apparatus or plasma membrane fractions. Limited protease digestion demonstrated that ...

Identification of components of the intracellular transport machinery of acylated proteins by a genome-wide RNAi screen [Elektronische Ressource] / presented by Julia Ritzerfeld : IDENTIFICATIO N O F CO M PO NENTS O F TH E INTRACELLU LAR TRANSPO RT M ACH INERY O F ACYLATED PRO TEINS BY A GENO M E‐W IDE RNAI SCREEN DISSERTATIO N submitted to the Combined Faculties for the Natural Sciences and for Mathematics of the Ruperto Caro la University of Heidelberg, Germany for the degree of Doctor of Natural Sciences Julia Ritzerfeld

Catalyzes the N-acylation of UDP-3-O-(hydroxytetradecanoyl)glucosamine using 3-hydroxytetradecanoyl-ACP as the acyl donor. Is involved in the biosynthesis of lipid A, a phosphorylated glycolipid that anchors the lipopolysaccharide to the outer membrane of the cell. Prefers (3R)-3-hydroxytetradecanoyl-ACP over (3R)-3-hydroxyhexadecanoyl-ACP as the acyl donor in vitro, which is consistent with the structure of E.coli lipid A that contains over 95% (R)-3-hydroxytetradecanoate at the 2 and 2 positions.

BYK-P 104 S Chemistry of 1,3-Dithiane ADISI Alkenes and Alkynes II Docking Analysis of various Social Networking sites Enzymatic acylation of di- and trisaccharides with fatty acids: choosing the appropriate enzyme, support and solvent Computational Studies of Subtilisin-Catalyzed Transesterification of Sucrose: Importance of Entropic Effects Effect of the Immobilization Method of Lipase from Thermomyces lanuginosus on Sucrose Acylation Comparative Surface Activities of Di and Trisaccharide Fatty Acid Esters Describing partially unfolded states of proteins from sparse NMR data Describing Partially Unfolded States of Proteins from Sparse NMR Ddata Towards the prediction of protein interaction partners using physical docking

and I-C (compounds of Formula I where R1 = Z-CEb-N(R2)(R3)), the hydroxy group of compound of Formula I-B (compounds of Formula I where R = Z-CH2OH) was converted to A2, a phihalimide group, following the procedures as described in Scheme 5 fin: the conversion of compound of Formula VII to compound of Formula VL Reaction of compound of Formula I-C* under conditions described in Scheme 4 afforded compound of Formula I-C. Reaction of compound of Formula I- C with but not limited to various alkylating agents, various aldehydes/ketones under reductive animation conditions, various acylating agents such as acetic anhydride, benzoyi chlorides, or with caiboxyiic acids in the presence of EDC or DCC with HOBT or HOAT, or with sulphonylating agents such as Ts2O or MeSC^Cl afforded compounds of Formula I-C * \ For example, in a typical preparation of compounds of Formula I-C (compounds of Formula I where R1 = Z^-CHT-NO^XR3)), a compound of Formula I-C is treated with a suitable acylating agent in ...

Researchers in Brazil found that women with fibromyalgia had decreased levels of acylated ghrelin, which were related to pain intensity.

Researchers in Brazil found that women with fibromyalgia had decreased levels of acylated ghrelin, which were related to pain intensity.

BioAssay record AID 213359 submitted by ChEMBL: Rate constant of acylation on trypsin was determined at 10 percent and at 95 minutes for maximum inhibition and no enzyme activity was recovered over the 2 h-time.

Lysine acetylation refers to addition of an acetyl moiety to the epsilon‐amino group of a lysine residue and is important for regulating protein functions in various organisms from bacteria to humans

Fat is an important energy source from food. More than 95% of dietary fat is long-chain triacylglycerols (TAG), the remaining being phospholipids (4.5%) and sterols. In the small intestine lumen, dietary TAG is hydrolyzed to fatty acids (FA) and monoacylglycerols (MAG) by pancreatic lipase. These products are then emulsified with the help of phospholipids (PL) and bile acids (BA) present in bile to form micelles. Free FAs and MAGs are taken up by the enterocyte where they are rapidly resynthesized in endoplasmic reticulum (ER) to form TAG. PLs from the diet as well as bile - mainly LPA - too are absorbed by the enterocyte and are acylated to form phosphatidic acid (PA), which is also converted into TAG. Absorbed cholesterol (CL) is acylated to cholesterol esters (CE). Within the ER, TAG joins CE and apolipoprotein B (ApoB) to form chylomicrons that enter circulation through the lymph ...

Fat is an important energy source from food. More than 95% of dietary fat is long-chain triacylglycerols (TAG), the remaining being phospholipids (4.5%) and sterols. In the small intestine lumen, dietary TAG is hydrolyzed to fatty acids (FA) and monoacylglycerols (MAG) by pancreatic lipase. These products are then emulsified with the help of phospholipids (PL) and bile acids (BA) present in bile to form micelles. Free FAs and MAGs are taken up by the enterocyte where they are rapidly resynthesized in endoplasmic reticulum (ER) to form TAG. PLs from the diet as well as bile - mainly LPA - too are absorbed by the enterocyte and are acylated to form phosphatidic acid (PA), which is also converted into TAG. Absorbed cholesterol (CL) is acylated to cholesterol esters (CE). Within the ER, TAG joins CE and apolipoprotein B (ApoB) to form chylomicrons that enter circulation through the lymph ...

Plays a role in lysophospholipid acylation. Transfers fatty acids to the 1-position via an enzyme-bound acyl-ACP intermediate in the presence of ATP and magnesium. Its physiological function is to regenerate phosphatidylethanolamine from 2-acyl-glycero-3-phosphoethanolamine (2-acyl-GPE) formed by transacylation reactions or degradation by phospholipase A1.

PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

2XR0: The Active Site Protonation States of Perdeuterated Toho-1 Beta-Lactamase Determined by Neutron Diffraction Support a Role for Glu166 as the General Base in Acylation.

Offers a method dedicated to stoichiometry quantification. StoichiolyzeR proposes a package leaning on the combined exploitation of information related to precursor and fragment ions data gathered from data-independent acquisitions (DIAs). This application is an approach which is able to consider peptides that include multiple lysine residues to census site-specific acylation stoichiometry.

Chitosan has many unique physical and chemical properties, acylation, sulfation and oxidation, grafting and crosslinking of hydroxyethyl, hydroxymethyl.

1. J. Am. Chem. Soc. 2014, 136, 11783-11791. Concerted Amidation of Activated Esters: Reaction Path and Origins of Selectivity in the Kinetic Resolution of Cyclic Amines via NHC and Hydroxamic Acid Co-Catalyzed Acyl Transfer Allen, S. E.; Hsieh, S.-Y.; Gutierrez, O.; Bode, J. W.; Kozlowksi, M. C. 2. Organometallics, 2

A servlet designed to get around the Same Origin Policy restriction for POSTing forms or parsing JSON while developing a Google Web Toolkit (GWT) base

In the past few years, much progress has been made in the understanding of how people maintain body weight and how homeostasis is affected.19-22 In 1999, ghrelin was discovered in the stomach as an appetite stimulatory signal from the periphery with structural resemblance to motilin.1,4,5,23 Previous studies have shown that acylated ghrelin produces stimulatory effects on food intake via activation of NPY, AGRP, and orexin in the hypothalamus, and on gastric emptying.4,5,23-25 However, very little is known about the physiological role of desacyl ghrelin. We found that administration of desacyl ghrelin produced inhibitory effects on feeding. Notably, the anorexigenic effect of desacyl ghrelin was inversely proportioned to that of the orexigenic effect of acylated ghrelin. Considerable evidence cumulatively indicates that rapid gastric emptying is closely related to overeating and obesity, as delayed gastric emptying is to anorexia and cachexia.26-28 We previously reported that acylated ghrelin ...

Membrane bound phospholipids require a distinct fatty acid composition. This is achieved through the deacylation-reacylation cycle that involves the breakdown of the parent phospholipid to a fatty acid and its lysophospholipid derivative by a phospholipase A activity. Subsequently, phospholipids are resynthesized through the action of an acyltransferase that attaches acyl-Coenzyme A thioesters to the lysophospholipid. This cycle must be carefully regulated so that the correct fatty acid composition of the phospholipids are maintained, otherwise the normal functioning of the membrane and membrane bound enzymes could be jeopardized. Thyroid hormones have profound effects on the heart. Since it is established that thyroid hormones regulate many lipid metabolizing enzymes, it is possible that the deacylation-reacylation cycle of certain phospholipids may also be regulated by thyroid hormones. The effect of a thyroid condition on phospholipid fatty acid metabolism was examined in isolated rat hearts ...

TY - JOUR. T1 - Enzymatic resolution of (±)-cis-2-aminocyclopentanol and (±)-cis-2- aminocyclohexanol. AU - Luna, Amparo. AU - Astorga, Covadonga. AU - Fülöp, F.. AU - Gotor, Vicente. PY - 1998/12/24. Y1 - 1998/12/24. N2 - (±)-cis-N-Benzyloxycarbonyl-2-aminocyclopentanol was efficiently resolved by O-acylation with Pseudomonas cepacia lipase, as was (±)-cis-N- benzyloxycarbonyl-2-aminocyclohexanol when Candida antarctica lipase was used.. AB - (±)-cis-N-Benzyloxycarbonyl-2-aminocyclopentanol was efficiently resolved by O-acylation with Pseudomonas cepacia lipase, as was (±)-cis-N- benzyloxycarbonyl-2-aminocyclohexanol when Candida antarctica lipase was used.. UR - http://www.scopus.com/inward/record.url?scp=0032564662&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0032564662&partnerID=8YFLogxK. U2 - 10.1016/S0957-4166(98)00482-0. DO - 10.1016/S0957-4166(98)00482-0. M3 - Article. AN - SCOPUS:0032564662. VL - 9. SP - 4483. EP - 4487. JO - Tetrahedron Asymmetry. JF - ...

Twenty-one non-peptide substituted desloratadine class compounds were synthesized as novel arginine vasopressin receptor antagonists from desloratadine via successive acylation, reduction and acylation reactions. Their structures were characterized by 1H-NMR and HRMS, their biological activity was evaluated by in vitro and in vivo studies. The in vitro binding assay and cAMP accumulation assay indicated that these compounds are potent selective V2 receptor antagonists. Among them compounds 1n, 1t and 1v exhibited both high affinity and promising selectivity for V2 receptors. The in vivo diuretic assay demonstrated that 1t presented remarkable diuretic activity. In conclusion, 1t is a potent novel AVP V2 receptor antagonist candidate.

Enzyme-catalyzed synthesis has been widely studied with lipases (EC 3.1.1.3), but feruloyl esterases (FAEs; EC 3.1.1.73) may provide advantages such as higher substrate affinity and regioselectivity in the synthesis of hydroxycinnamate saccharide esters. These compounds are interesting because of their amphiphilicity and antioxidative potential. Synthetic reactions using mono- or disaccharides as one of the substrates may moreover direct new routes for biomass upgrading in the biorefinery. The paper reviews the available data for enzymatic hydroxycinnamate saccharide ester synthesis in organic solvent systems as well as other enzymatic hydroxycinnamate acylations in ionic liquid systems. The choice of solvent system is highly decisive for enzyme stability, selectivity, and reaction yields in these synthesis reactions. To increase the understanding of the reaction environment and to facilitate solvent screening as a crucial part of the reaction design, the review explores the use of activity ...

Objective HCV is intimately linked with the liver lipid metabolism, devoted to the efflux of triacylglycerols stored in lipid droplets (LDs) in the form of triacylglycerol-rich very-low-density lipoproteins (VLDLs): (i) the most infectious HCV particles are those of lowest density due to association with triacylglycerol-rich lipoproteins and (ii) HCV-infected patients frequently develop hepatic steatosis (increased triacylglycerol storage). The recent identification of lysophosphatidylcholine acyltransferase 1 (LPCAT1) as an LD phospholipid-remodelling enzyme prompted us to investigate its role in liver lipid metabolism and HCV infectious cycle. ...

Enzyme selectivity means that the enzyme´s preferences towards competing substrates will be different. In this thesis, the enzyme selectivity has been studied for utilization in synthesis of functionalized macromonomers. The aim was to study how the inherent -or introduced - selectivity of lipases can be used to introduce thiol‐ or enefunctionalities into short polyesters. Thiol‐ and ene‐functionalized renewable organic precursor molecules in combination with thiol‐ene click chemistry opens up for a sustainable material production. Lipases do not normally affect ene‐moieties and the preference towards thiols is low, enabling introduction of these functional groups for further modifications. In addition, lipases have been shown to be good catalysts in the formation of polyesters, both via ring‐opening and polycondensation polymerization.. In paper I Candida antarctica lipase B was used to end‐functionalize poly(ε‐caprolactone) with free thiols in a one‐pot reaction. The ...

Description: M.Sc. , Lewis acids play an important role in catalysis; they are associated with mild conditions, high selectivities and unique reactivities. Traditional Lewis acids such as AlCb and BF3 successfully catalyse such well known reactions as the Friedel-Crafts acylation reaction, Aldol condensation reactions and many more. These catalysts, however, must be used in a stoichiometric amount and are destroyed during the aqueous workup procedures. Lately, there has been a lot of interest in the role of metal triflate as Lewis acid catalysts. They were found to be effective in a wide range of reactions when used in catalytic amounts. They were also found to be recyclable and reusable without the loss of activity. Most of this research has been centred around the lanthanide triflates as well as scandium, bismuth and yttrium triflates. Very little research has been done using aluminium triflate and this triflate forms the focus ofthis study. The work contained in this dissertation demonstrates ...

Interpretive Summary: Technical Abstract: Trichothecenes are among the mycotoxins of greatest concern to food and feed safety and are produced by at least two lineages of Fusarium: F. sambucinum (FSAMSC) and F. incarnatum-equiseti (FIESC) species complexes. Trichothecene biosynthesis begins with the formation of a cyclic sesquiterpene followed by up to eight oxygenation and four acylation reactions. Most trichothecene biosynthetic genes (TRI) are co-regulated and located in a cluster. All Fusarium TRI cluster homologs characterized to date include two regulatory genes that encode a C2H2 zinc finger (TRI6) and a fungal transcription factor domain (TRI10). Functional analysis of FSAMSC members indicate that TRI6 regulates expression of structural genes in the TRI cluster, while TRI10 regulates TRI6 expression. Here, we characterized a novel gene, TRI21, located in the TRI cluster of FIESC but not FSAMSC, which encodes a Zn2Cys6 transcription factor. Gene deletion and precursor feeding analyses ...

Eatons reagent (7.7 wt% phosphorus pentoxide solution in methanesulfonic acid) is used as an alternative to polyphosphoric acid in chemical synthesis to promote acylation reactions. Eaton, P. E.; Carlson, G. R.; Lee, J. T. (1973). Phosphorus pentoxide-methanesulfonic acid. Convenient alternative to polyphosphoric acid. J. Org. Chem. 38 (23): 4071. doi:10.1021/jo00987a028 ...

Priming for virus-specific CD8+ but not CD4+ cytotoxic T lymphocytes with synthetic lipopeptide is influenced by acylation units and liposome encapsulation.

Video explaining EAS: Friedel-Crafts Acylation Mechanism for Organic Chemistry. This is one of many videos provided by Clutch Prep to prepare you to succeed in

Purpose: : Transducin (Gt) is present in outer segments (OS) of dark-adapted rods, and it re-localizes to the inner compartments in light. Here we examined the molecular mechanism underlying this re-distribution. Methods: : Mouse eyecups or retinas were incubated, in light or dark, in a culture medium under conditions permitting the control of ATP, GTP or GTP analogs in the cells. Localization of rod and cone transducin subunits in the cells was examined by immunofluorescence microscopy. Retinas were fractionated by ultracentrifugation, and the presence of Gt was determined by western blot. The following mouse models were examined: 1. Gna1-/-; Gna2+, where cone Gαt is expressed in rods; 2. Nrl-/-, containing only cone-like photoreceptors; 3. Gß5-/-; and 4. RGS9-/-. N-Acylation status of Gαt was determined by mass-spectrometry. Results: : Re-localization of rod Gt in light occurs even in ATP-depleted rod cells. GTP is necessary and sufficient for the departure of Gt from the OS, and the ...

The lipids in the lipid bilayers of cell membranes are mainly phospholipids. When mixed with water, phospholipids and glycolipids form bilipid structures spontaneously. This is a result of the hydrophilic and strongly polar head of each lipid molecule, which contains sugar or phosphate, associating with water; and conversely, the non-polar alkyl tail of the fatty acyl groups aggregating by hydrophobic interactions.. Two types of phospholipids are glycerolphospholipids and sphingolipids.. Glycerophospholipids are composed fo a glycerol linked to two fatty acyl groups and one phosphate group, which could in turn be linked to other groups, including ethanolamine, choline, inositol, or serine, which are conventionally named, in these examples, as phosphatidyl [other group name], respectively.. Sphingolipids are composed of a sphingosine linked to one fatty acyl group. They are usually linked to a phosphate plus choline (sphingomyelin), sugar (ceramides), or complex oligosaccharide ...

S-palmitoylation consists in the covalent attachment of a 16-carbon chain palmitic acid to a cysteine residue of a target protein through a thioester bond, regulating thus the localization and/or function of the modified protein because of the consequent change in hydrophobicity (18, 19). Although several Palmitoyl-proteome analyses have been described in the last years, only few have been using protozoan parasites (12, 53⇓-55). Interestingly, in all parasites where the role of palmitoylation has been described, it appears to be involved in vital processes such as invasion and motility (12, 53⇓-55). In this context, here we performed the first large-scale description of palmitoylated proteins of the extracellular human pathogen T. vaginalis, identifying 363 putative palmitoylated proteins. Among the isolated proteins, 8 TvPAT-like molecules were identified. Interestingly, only one of them contain the classical DHHC-CRD domain whereas the remaining seven contain variants of the DHHC-CRD ...

N-Acylsulfonamides usually react with nucleophiles by acyl transfer and C-N bond fission. However, the hydrolysis of N-acyl -sultams is a sulfonyl transfer reaction that occurs with S-N fission and opening of the four-membered ring. Similar to other -sultams, the N-acyl derivatives are at least 106-fold more reactive than N-acyl sulfonamides. 3-Oxo--sultams are both -lactams and -sultams but also hydrolyze with preferential S-N bond fission.. ...

Although phosphorine and pyridine are structurally similar, phosphorines are far less basic. The pKas of C5H5PH+ and C5H5NH+ are respectively -16.1 and 5.2.[6] Methyl lithium adds to phosphorus in phosphorine whereas it adds to the 2-position of pyridine.[8]. Phosphorine undergoes electrophilic substitution reactions like ordinary aromatic compounds: bromination, acylation, and so on. ...

Classifying the isomeric 4-amino-cyclohexane-carboxylic acids and their acyl derivatives in the cis- or trans series is certain thanks to the investigations of J Houben and A Pfau, Ber dtsch chem Ges 49 2294 (1916), L Orthner and R Hein (Biochem Z 262 461 (1933), G Wendt (Chem Ber 75 425 (1942) and E Ferber and H Br ckner (Chem Ber 76 1019 (1943).. As the acid saponification in mild conditions of the ethyl ester prepared from the amino acids and their hydrochlorides returned to the respective starting product only, the steric classification can be considered valid for the ethyl esters too.. Spectroscopic investigation of the constitution of the amides prepared confirmed their constitution. Comparison of the IR photos of cis-cis-IV, trans-trans-IV and cis-trans-IV as well as cis-VI and trans-VI shows that the compounds in the cis- and trans-series have the same configuration.. The differing steric alignment of the COOC2H5 group in the cis- and trans-forms is evident from the homogenous shifts in ...

Q 8. A compound with molecular mass 180 is acylated with {tex} \mathrm { CH } _ { 3 } \mathrm { COCl } {/tex} to get a compound with molecular mass {tex} 390 . {/tex} The number of amino groups present per molecule of the former compound is: ...

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