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alkyl glycerol

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https://www.readbyqxmd.com/read/28629973/%C3%AE-eleostearic-acid-containing-triglycerides-for-a-continuous-assay-to-determine-lipase-sn-1-and-sn-3-regio-preference
#1
Meddy El Alaoui, Laurent Soulère, Alexandre Noiriel, Yves Queneau, Abdelkarim Abousalham
Lipases are essentially described as sn-1 and sn-3 regio-selective. Actually few methods are available to measure this lipase regio-selectivity, moreover they require chiral chromatography analysis or specific derivations which are discontinuous and time consuming. In this study we describe a new, convenient, sensitive and continuous spectrophotometric method to screen lipases regio-selectivity using synthetic triglycerides (TG) containing α-eleostearic acid (9Z, 11E, 13E-octadecatrienoic acid) either at the sn-1 position [1-α-eleostearoyl-2,3-octadecyl-sn-glycerol (sn-EOO)] or at the sn-3 position [1,2-octadecyl-3-α-eleostearoyl-sn-glycerol (sn-OOE)] and coated onto the wells of microtiter plates...
June 16, 2017: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/28627891/effect-of-deep-eutectic-solvent-nanostructure-on-phospholipid-bilayer-phases
#2
Saffron Jade Bryant, Rob Atkin, Gregory G Warr
Phospholipids are shown by solvent penetration experiments to form lamellar phases and spontaneously spawn vesicles in a wide range of deep eutectic solvents (DESs) composed of alkylammonium halide salts and glycerol or ethylene glycol, which are shown to be nanostructured by X-ray scattering. In contrast with molecular solvents, the chain melting temperature of each phospholipid, which determines the stability of the swellable bilayer phase, depends on the structure of the cation, anion and molecular H-bond donor that constitute the DES...
June 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28573294/transition-from-nematic-to-gyroid-type-cubic-soft-self-assembly-by-side-chain-engineering-of-%C3%AF-conjugated-sticky-rods
#3
Marco Poppe, Changlong Chen, Helgard Ebert, Silvio Poppe, Marko Prehm, Christoph Kerzig, Feng Liu, Carsten Tschierske
A sequence of liquid crystalline phases, involving cybotactic nematics, a lamellar phase, bicontinuous cubics and triangular honeycombs, was observed for oligo(phenylene ethynylene) based X-shaped bolapolyphiles with two long lateral alkyl chains and sticky ends provided by glycerol groups. In the cubic phase with Ia3[combining macron]d lattice - which is tailored by alkyl chain engineering - the aromatic cores are organized on the gyroid minimal surface in 3D curved layers of almost parallel aligned π-conjugated rods...
June 21, 2017: Soft Matter
https://www.readbyqxmd.com/read/28572922/migration-of-nonylphenol-and-plasticizers-from-polyvinyl-chloride-stretch-film-into-food-simulants-rapeseed-oil-and-foods
#4
Yoko Kawamura, Yuko Ogawa, Motoh Mutsuga
Nonylphenol (NP) has been suspected as an endocrine-disrupting chemical. Japanese polyvinyl chloride (PVC) stretch films contained 0.5-3.3 mg/g of NP and 100-400 mg/g of plasticizers such as diisononyl adipate (DINA), di-n-alkyl adipate (DAA), and diacetyllauroyl glycerol (DALG). Migration of NP and plasticizers from PVC stretch films into food simulants (water; 4% acetic acid; 20%, 50%, and 95% ethanol; and heptane), rapeseed oil, and foods was investigated. Plasticizers migrated only in small amounts into aqueous simulants and foods, although they migrated at much higher levels into 50% and 95% ethanol, heptane, rapeseed oil, and fatty foods, whereas NP more easily migrated into aqueous simulants and foods...
May 2017: Food Science & Nutrition
https://www.readbyqxmd.com/read/28551204/ecotoxicity-and-qsar-studies-of-glycerol-ethers-in-daphnia-magna
#5
Eduardo Perales, Jose Ignacio García, Elisabet Pires, Luis Aldea, Laura Lomba, Beatriz Giner
Glycerol is currently considered a raw, renewable material, which can be used to synthesize new glycerol derivatives that may be used as green solvents. However, these compounds must be environmentally evaluated before their use. The acute ecotoxicity of a series of mono-, di-, and trialkyl ethers synthesized from glycerol for the crustacean Daphnia magna has been studied. The EC50 values of these ethers after 24 h of exposure were determined according to the OECD 202 protocol. Their possible structural-toxicity relationships according to different alkyl substituents have been discussed after applying different QSAR models (with the DARC-PELCO approach and topological parameters)...
May 19, 2017: Chemosphere
https://www.readbyqxmd.com/read/28494957/antioxidant-and-membrane-binding-properties-of-serotonin-protect-lipids-from-oxidation
#6
Slim Azouzi, Hubert Santuz, Sandrine Morandat, Catia Pereira, Francine Côté, Olivier Hermine, Karim El Kirat, Yves Colin, Caroline Le Van Kim, Catherine Etchebest, Pascal Amireault
Serotonin (5-hydroxytryptamine, 5-HT) is a well-known neurotransmitter that is involved in a growing number of functions in peripheral tissues. Recent studies have shown nonpharmacological functions of 5-HT linked to its chemical properties. Indeed, it was reported that 5-HT may, on the one hand, bind lipid membranes and, on the other hand, protect red blood cells through a mechanism independent of its specific receptors. To better understand these underevaluated properties of 5-HT, we combined biochemical, biophysical, and molecular dynamics simulations approaches to characterize, at the molecular level, the antioxidant capacity of 5-HT and its interaction with lipid membranes...
May 9, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28457130/azide-modified-membrane-lipids-synthesis-properties-and-reactivity
#7
Sindy Lindner, Kai Gruhle, Rico Schmidt, Vasil M Garamus, Daniel Ramsbeck, Gerd Hause, Annette Meister, Andrea Sinz, Simon Drescher
In the present work, we describe the synthesis and the temperature-dependent behavior of photoreactive membrane lipids as well as their capability to study peptide/lipid interactions. The modified phospholipids contain an azide group either in the middle part or at the end of an alkyl chain and also differ in the linkage (ester vs ether) of the second alkyl chain. The temperature-dependent aggregation behavior of the azidolipids was studied using differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, and small-angle X-ray scattering (SAXS)...
May 10, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28453907/aggregation-behaviour-of-non-ionic-twinned-amphiphiles-and-their-application-as-biomedical-nanocarriers
#8
Abhishek K Singh, Bala N S Thota, Boris Schade, Katharina Achazi, Abdullah Khan, Christoph Böttcher, Sunil K Sharma, Rainer Haag
A new class of twinned amphiphiles was developed by conjugating a pair of hydrophilic head groups from mPEG chains (Mn: 350 or 1000) and a pair of hydrophobic segments from linear alkyl chains (C11 or C18) through a novel spacer synthesized from glycerol and p-hydroxybenzoic acid. The aggregation phenomena of the amphiphiles were proven by DLS and fluorescence experiments, whereas size and morphology of the aggregates were evaluated by cryo-TEM, the measurements proved the formation of globular, thread-like or rod-like micelles as well as planar double-layer assemblies, depending on the amphiphile's molecular structure...
April 28, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28243654/effect-of-chirality-on-monoacylglycerol-ester-monolayer-characteristics-3-monostearoyl-sn-glycerol
#9
D Vollhardt, G Brezesinski
The effect of chirality on the thermodynamic behavior, the morphological features, and the 2D lattice structures of 3-monostearoyl-sn-glycerol monolayers is studied. The present study focusses on the influence of the alkyl chain length on the chiral discrimination. Surface pressure-area (π-A) isotherms, Brewster angle microscopy (BAM), and particularly, grazing incidence X-ray diffraction (GIXD) are the experimental basis of the presented results. The π-A isotherms of the enantiomeric 3-monostearoyl-sn-glycerol monolayers measured between 25 and 38 °C resemble those of the racemic 1-monostearoyl-rac-glycerol monolayers, thus indicating small energetic differences between the enantiomeric and the racemic forms...
February 28, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28214513/molecular-dynamics-simulation-study-of-the-effect-of-glycerol-dialkyl-glycerol-tetraether-hydroxylation-on-membrane-thermostability
#10
Carme Huguet, Susanne Fietz, Antoni Rosell-Melé, Xavier Daura, Lionel Costenaro
Archaeal tetraether membrane lipids span the whole membrane width and present two C40 isoprenoid chains bound by two glycerol groups (or one glycerol and calditol). These lipids confer stability and maintain the membrane fluidity in mesophile to extremophile environments, making them very attractive for biotechnological applications. The isoprenoid lipid composition in archaeal membranes varies with temperature, which has placed these lipids in the focus of paleo-climatological studies for over a decade. Non-hydroxylated isoprenoid archaeal lipids are typically used as paleo-thermometry proxies, but recently identified hydroxylated (OH) derivatives have also been proposed as temperature proxies...
February 16, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28167425/effect-of-cation-alkyl-chain-length-on-surface-forces-and-physical-properties-in-deep-eutectic-solvents
#11
Zhengfei Chen, Michael Ludwig, Gregory G Warr, Rob Atkin
Deep eutectic solvents (DESs) have been prepared from mixtures of alkyl ammonium bromide salts (ethylammonium bromide, propylammonium bromide and butylammonium bromide) and glycerol at a 1: 2 M ratio. These DESs reveal the effect of cation alkyl chain length on interfacial structure at mica (a model anionic) surface. As the cation chain length is increased it becomes more amphiphilic and solvophobic, leading to stronger association of alkyl chains, as revealed by atomic force microscope force curve measurements...
May 15, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28140521/continuous-flow-o-alkylation-of-biobased-derivatives-with-dialkyl-carbonates-in-the-presence-of-magnesium-aluminium-hydrotalcites-as-catalyst-precursors
#12
Lisa Cattelan, Alvise Perosa, Piero Riello, Thomas Maschmeyer, Maurizio Selva
The base-catalysed reactions of OH-bearing biobased derivatives (BBDs) including glycerol formal, solketal, glycerol carbonate, furfuryl alcohol and tetrahydrofurfuryl alcohol with non-toxic dialkyl carbonates (dimethyl and diethyl carbonate) were explored under continuous-flow (CF) conditions in the presence of three Na-exchanged Y- and X-faujasites (FAUs) and four Mg-Al hydrotalcites (HTs). Compared to previous etherification protocols mediated by dialkyl carbonates, the reported procedure offers substantial improvements not only in terms of (chemo)selectivity but also for the recyclability of the catalysts, workup, ease of product purification and, importantly, process intensification...
April 10, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28117757/alkylglycerol-derivatives-a-new-class-of-skin-penetration-modulators
#13
Sergio Alberto Bernal-Chávez, Lilia Yazmín Pérez-Carreto, María Guadalupe Nava-Arzaluz, Adriana Ganem-Rondero
The absorption modulating activity of two alkylglycerol derivatives (batyl and chimyl alcohol) on skin barrier properties was evaluated. Biophysical tests such as transepidermal water loss (TEWL) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, as well as in vitro skin permeation studies, were performed in order to determine the effect of these compounds as chemical absorption modulators. Four drugs were used as models: three NSAIDS (diclofenac, naproxen, and piroxicam) and glycyrrhizic acid...
January 22, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28103109/impaired-spermatogenesis-in-the-twitcher-mouse-a-morphological-evaluation-from-the-seminiferous-tubules-to-epididymal-transit
#14
Alice Luddi, Martina Gori, Laura Crifasi, Camilla Marrocco, Giuseppe Belmonte, Elvira Costantino-Ceccarini, Paola Piomboni
Spermatogenesis is a complex process of proliferation and differentiation during male germ cell development whereby undifferentiated spermatogonial germ cells evolve into maturing spermatozoa. In this developmental process the interactions between different cell types are finely regulated, hence any disruption in these relationships leads to male infertility. The twitcher mouse, the murine model of Krabbe disease, is characterized by deficiency of galactosylceramidase, an enzyme also involved in the metabolism of the galactosyl-alkyl-acyl-glycerol, the precursor of sulfogalactosyl-alkyl-acyl-glycerol, the most abundant glycolipid in spermatozoa...
April 2017: Systems Biology in Reproductive Medicine
https://www.readbyqxmd.com/read/28089346/detection-of-unusual-very-long-chain-fatty-acid-and-ether-lipid-derivatives-in-the-fibroblasts-and-plasma-of-patients-with-peroxisomal-diseases-using-liquid-chromatography-mass-spectrometry
#15
Shigeo Takashima, Kayoko Toyoshi, Takahiro Itoh, Naomi Kajiwara, Ayako Honda, Akiko Ohba, Shoko Takemoto, Satoshi Yoshida, Nobuyuki Shimozawa
Metabolic changes occur in patients with peroxisomal diseases owing to impairments in the genes involved in peroxisome function. For diagnostic purposes, saturated very-long-chain fatty acids (VLCFAs) such as C24:0 and C26:0, phytanic acid, pristanic acid, and plasmalogens are often measured as metabolic hallmarks. As the direct pathology of peroxisomal disease is yet to be fully elucidated, we sought to explore the fatty acid species that accumulate in patients with peroxisomal diseases. We developed a method for detecting a range of fatty acids implicated in peroxisomal diseases such as Zellweger syndrome (ZS) and X-linked adrenoleukodystrophy (X-ALD)...
March 2017: Molecular Genetics and Metabolism
https://www.readbyqxmd.com/read/28073164/protective-role-of-endogenous-plasmalogens-against-hepatic-steatosis-and-steatohepatitis
#16
Jung Eun Jang, Han-Sol Park, Hyun Ju Yoo, In-Jeoung Baek, Ji Eun Yoon, Myoung Seok Ko, Ah-Ram Kim, Hyoun Sik Kim, Hye-Sun Park, Seung Eun Lee, Seung-Whan Kim, Su Jung Kim, Jaechan Leem, Yu Mi Kang, Min Kyo Jung, Chan-Gi Pack, Chong Jai Kim, Chang Ohk Sung, In-Kyu Lee, Joong-Yeol Park, José C Fernández-Checa, Eun Hee Koh, Ki-Up Lee
Free cholesterol (FC) accumulation in the liver is an important pathogenic mechanism of nonalcoholic steatohepatitis (NASH). Plasmalogens, key structural components of the cell membrane, act as endogenous antioxidants and are primarily synthesized in the liver. However, the role of hepatic plasmalogens in metabolic liver disease is unclear. In this study, we found that hepatic levels of docosahexaenoic acid (DHA)-containing plasmalogens, expression of glyceronephosphate O-acyltransferase (Gnpat, the rate-limiting enzyme in plasmalogen biosynthesis), and expression of Pparα were lower in mice with NASH caused by accumulation of free cholesterol (FC) in the liver...
January 10, 2017: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/28049317/spectral-assignment-and-orientational-analysis-in-a-vibrational-sum-frequency-generation-study-of-dppc-monolayers-at-the-air-water-interface
#17
Rong-Juan Feng, Xia Li, Zhen Zhang, Zhou Lu, Yuan Guo
The interfacial behavior of the benchmark zwitterionic phospholipid molecule dipalmitoylphosphatidylcholine (DPPC) has been extensively investigated by surface-selective vibrational sum frequency generation spectroscopy (VSFG). However, there is still a lack of agreement between various orientational measurements of phospholipid monolayers at the air/water interface, mainly because of the difficulty in assigning congested VSFG features. In this study, polarization-dependent VSFG measurements reveal a frequency shift between the in-plane and out-of-plane antisymmetric stretching modes of the terminal methyl groups in the DPPC alkyl tails, favoring the model of Cs local symmetry rather than the previously assumed C3v symmetry...
December 28, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/27934510/conserved-molecular-superlattices-in-a-series-of-homologous-synthetic-mycobacterial-cell-wall-lipids-forming-interdigitated-bilayers
#18
Birte Martin-Bertelsen, Anan Yaghmur, Henrik Franzyk, Sarah Justesen, Jacob J K Kirkensgaard, Camilla Foged
Synthetic analogues of the cell-wall lipid monomycoloyl glycerol (MMG) are promising as next-generation vaccine adjuvants. In the present study, the thermotropic phase behavior of an array of synthetic MMG analogues was examined by using simultaneous small- and wide-angle X-ray scattering under excess water conditions. The MMG analogues differed in the alkyl chain lengths and in the stereochemistry of the polar glycerol headgroup or of the lipid tails (native-like versus alternative compounds). All MMG analogues formed poorly hydrated lamellar phases at low temperatures and inverse hexagonal (H2) phases at higher temperatures prior to melting...
December 6, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/27891818/exploiting-deep-eutectic-solvents-and-organolithium-reagent-partnerships-chemoselective-ultrafast-addition-to-imines-and-quinolines-under-aerobic-ambient-temperature-conditions
#19
Cristian Vidal, Joaquín García-Álvarez, Alberto Hernán-Gómez, Alan R Kennedy, Eva Hevia
Shattering the long-held dogma that organolithium chemistry needs to be performed under inert atmospheres in toxic organic solvents, chemoselective addition of organolithium reagents to non-activated imines and quinolines has been accomplished in green, biorenewable deep eutectic solvents (DESs) at room temperature and in the presence of air, establishing a novel and sustainable access to amines. Improving on existing methods, this approach proceeds in the absence of additives; occurs without competitive enolization, reduction or coupling processes; and reactions were completed in seconds...
December 23, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/27791296/key-non-metal-ingredients-for-cu-catalyzed-click-reactions-in-glycerol-nanoparticles-as-efficient-forwarders
#20
Marta Rodríguez-Rodríguez, Patricia Llanes, Christian Pradel, Miquel A Pericàs, Montserrat Gómez
The effect of long-alkyl-chain amines in CuI-assisted azide-alkyne cycloadditions of terminal alkynes with organic azides in glycerol and other environmentally benign solvents (water, ethanol) has been examined. The presence of these additives favors the in situ formation of Cu(I) -based nanoparticles and results in an increase of the catalytic reactivity. In glycerol, liquid-phase transmission electron microscopy (TEM) analyses, enabled by the negligible vapor pressure of this solvent, proved that Cu(I) nanoparticles are responsible for the observed catalytic activity...
December 12, 2016: Chemistry: a European Journal
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