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Marco Muth, Stefanie Rothkötter, Steven Paprosch, Reiner P Schmid, Klaus Schnitzlein
Lipase-catalyzed hydrolysis of triglycerides yields glycerol and free fatty-acids, provided that the enzyme is non-regioselective. For an Sn-1,3 regioselective enzyme, such as lipase from Thermomyces lanuginosus, the final product is no longer glycerol but Sn-2 monoglyceride instead. However, surface active molecules generated by lipolysis may have a detrimental effect on the interfacial biocatalysis since it is known that low molecular weight surfactants can displace proteins from interfaces. By using drop profile analysis tensiometry, we evaluated the interfacial properties of the lipase-generated molecules and their competitive effect on the adsorption behavior of the lipase and on the proceeding lipolysis...
October 12, 2016: Colloids and Surfaces. B, Biointerfaces
Bartosz Gląb, Mirela Beganovic, Sanket Anaokar, Meng-Shu Hao, Allan Rasmusson, Jana Patton-Vogt, Antoni Banaś, Sten Stymne, Ida Lager
Glycero-3-phosphocholine (GPC), the product of the complete deacylation of phosphatidylcholine (PC), was long thought to not be a substrate for reacylation. However it was recently shown that cell-free extracts from yeast and plants could acylate GPC with acyl groups from acyl-CoA. By screening enzyme activities of extracts derived from a yeast knock-out collection, we were able to identify and clone the yeast gene (GPC1) encoding the enzyme, named glycerophosphocholine acyltransferase (GPCAT). By homology search we also identified and cloned GPCAT genes from three plant species...
October 7, 2016: Journal of Biological Chemistry
Daniel P Pike, Celine L Hartman, Gregory J Weissler, Elisa N D Palladino, Carolyn J Albert, David A Ford
Platelet-activating factor (PAF) is a potent biologically active phospholipid that mediates human physiological and pathophysiologic responses. PAF levels increase transiently and are typically assessed by techniques with limitations related to expense, sensitivity, pre-analysis derivatization and interference with isobaric molecules. This study elucidates a facile, accurate liquid chromatography-mass spectrometry analytical method for PAF. In negative ion mode using electrospray ionization, collisionally-activated dissociation analysis showed a unique product ion for acetate adducts of PAF molecular species representing the loss of methyl acetate from the polar head group and loss of a part of the acetate group from the sn-2 position...
October 18, 2016: Lipids
I C Sampaio, P H Q S Medeiros, F A P Rodrigues, P A Cavalcante, S A Ribeiro, J S Oliveira, M M G Prata, D V S Costa, S G C Fonseca, M M Guedes, A M Soares, G A C Brito, A Havt, S R Moore, A A M Lima
Undernutrition represents a major public health challenge for middle- and low-income countries. This study aimed to evaluate whether a multideficient Northeast Brazil regional basic diet (RBD) induces acute morphological and functional changes in the ileum of mice. Swiss mice (∼25 g) were allocated into two groups: i) control mice were fed a standard diet and II) undernourished mice were fed the RBD. After 7 days, mice were killed and the ileum collected for evaluation of electrophysiological parameters (Ussing chambers), transcription (RT-qPCR) and protein expression (western blotting) of intestinal transporters and tight junctions...
October 10, 2016: Brazilian Journal of Medical and Biological Research, Revista Brasileira de Pesquisas Médicas e Biológicas
Kadari Ramaswamy, Velchuri Radha, M Malathi, Muga Vithal, Nagegownivari R Munirathnam
The disposal and reuse of waste printed circuit boards have been the major global concerns. Printed circuit boards, a form of Electronic waste (hereafter e-waste), have been chemically processed, doped with Ag(+), Cu(2+) and Sn(2+), and used as visible light photocatalysts against the degradation of methylene blue and methyl violet. The elemental analyses of pristine and metal doped printed circuit board were obtained using energy dispersive X-ray fluorescence (EDXRF) spectra and inductively coupled plasma optical emission spectroscopy (ICP-OES)...
October 3, 2016: Waste Management
Dapeng Wu, Fujuan Wang, Hongju Wang, Kun Cao, Zhiyong Gao, Fang Xu, Kai Jiang
An in situ technique was developed to deposit Ag@Ag2S core-shell quantum dots on a SnO2 mesoporous film for solar energy conversion. When adopted as a photoanode, an impressive high photocurrent density of ∼25.6 mA cm(-2) was demonstrated in a cell configuration using polysulfide S(2-)/Sn(2-) as an electrolyte and Cu2S/brass as a counter electrode, which leads to a power conversion efficiency of ∼0.784% for this environmentally benign device. Optical measurements showed that Ag nanoparticles could be employed as plasmon resonance centers to enhance the harvesting efficiency of incident light at the visible and near-infrared range...
October 18, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Petr Zacek, Michael Bukowski, Thad Rosenberger, Matthew Picklo
Phosphatidylcholine (PC) species in human plasma are used as biomarkers of disease. PC biomarkers are often limited by the inability to separate isobaric PCs. In this work, we developed a targeted shotgun approach for analysis of isobaric and isomeric PCs. This approach is comprised of two mass spectrometric (MS) methods: a precursor ion scanning of mass m/z 184 in positive mode (PIS m/z +184) and MS3 fragmentation in negative mode, both performed on the same instrument, a hybrid triple quadrupole ion-trap mass spectrometer...
September 29, 2016: Journal of Lipid Research
Yaicel G Proenza, Miguel A F de Souza, Ricardo L Longo
The gas-phase reactions of XH(-) (X=O, S) + CH3 Y (Y=F, Cl, Br) span nearly the whole range of SN 2 pathways, and show an intrinsic reaction coordinate (IRC) (minimum energy path) with a deep well owing to the CH3 XH⋅⋅⋅Y(-) (or CH3 S(-) ⋅⋅⋅HF) hydrogen-bonded postreaction complex. MP2 quasiclassical-type direct dynamics starting at the [HX⋅⋅⋅CH3 ⋅⋅⋅Y](-) transition-state (TS) structure reveal distinct mechanistic behaviors. Trajectories that yield the separated CH3 XH+Y(-) (or CH3 S(-) +HF) products directly are non-IRC, whereas those that sample the CH3 XH⋅⋅⋅Y(-) (or CH3 S(-) ⋅⋅⋅HF) complex are IRC...
November 2, 2016: Chemistry: a European Journal
Qiujia Li, Xiaolong Dong, Weiwei Zheng, Hongyu Zhang
The phospholipase A2 (PLA2) gene encodes the enzyme that catalyzes the hydrolysis of phospholipids (PLs) from the sn-2 position. However, little is known about its role in humoral immune responses. In this study, we investigated the expression profile of PLA2 in different tissues and developmental stages in Bactrocera dorsalis (Hendel), and the results showed that the transcriptional level of PLA2 was high in the egg and mature stage and in the testis tissue. Bacterial infection increased the expression of PLA2, and the highest degree of up-regulation appeared in the fat body...
September 16, 2016: Developmental and Comparative Immunology
Merve Zeyrek Ongun, Kadriye Ertekin, Said Nadeem, Ozgül Birel
Recent investigations indicated that same concentrations of the ionic silver have harmful effects on aquatic life, bacteria and human cells. Herein we report chemosensory properties of N,N (') -Bis(4-{2-[2-(2-methoxyethoxy)ethoxy] eth- oxy}phenyl) -3,4:9,10-perylene tetracarboxydiimide (PERKAT) towards ionic silver. The dye doped sensing agents were prepared utilizing ethyl cellulose (EC) and poly (methylmethacrylate) (PMMA) and then forwarded to electrospinning to prepare sensing fibers or mats. The PERKAT exhibited bright emission in embedded forms in EC or in the solvents of N,N-Dimethylformamide (DMF), Dichloromethane (DCM), Tetrahydrofurane (THF) and in the mixture of DCM/ethanol...
September 13, 2016: Journal of Fluorescence
Lígia Pimentel, Ana Gomes, Manuela Pintado, Luis Miguel Rodríguez-Alcalá
The lipid fraction of milk is one of the most complex matrixes in foodstuffs due to the presence of a high number of moieties with different physical and chemical properties. Glycerolipids include glycerol and two fatty acids esterified in positions sn-1 and sn-2 with higher concentration of unsaturated fatty acids than in the triglyceride fraction of milk. Sphingolipids consist of a sphingoid base linked to a fatty acid across an amide bond. Their amphiphilic nature makes them suitable to be added into a variety of foods and recent investigations show that phospholipids, mainly phosphatidylserine and sphingomyelin, can exert antimicrobial, antiviral, and anticancer activities as well as positive effects in Alzheimer's disease, stress, and memory decline...
2016: Journal of Analytical Methods in Chemistry
Petr Zimmermann, Pavel Sobotík, Pavel Kocán, Ivan Ošt'ádal, Mykhailo Vorokhta, Robert George Acres, Vladimír Matolín
Interaction of ethylene (C2H4) with Si(001)-Sn-2 × 2 and Si(001)-In-2 × 2 at room temperature has been studied using core level (C 1s) X-ray photoelectron spectroscopy with synchrotron radiation and scanning tunneling microscopy. Sn and In form similar dimer chains on Si(001)2 × 1, but exhibit different interaction with ethylene. While ethylene adsorbs on top of Sn dimers of the Si(001)-Sn-2 × 2 surface, the Si(001)-In-2 × 2 surface turned out to be inert. Furthermore, the reactivity of the Sn terminated surface is found to be considerably decreased in comparison with Si(001)2 × 1...
September 7, 2016: Journal of Chemical Physics
Douglas H Fabini, Geneva Laurita, Jonathon S Bechtel, Constantinos C Stoumpos, Hayden A Evans, Athanassios G Kontos, Yannis S Raptis, Polycarpos Falaras, Anton Van der Ven, Mercouri G Kanatzidis, Ram Seshadri
Stable s(2) lone pair electrons on heavy main-group elements in their lower oxidation states drive a range of important phenomena, such as the emergence of polar ground states in some ferroic materials. Here we study the perovskite halide CsSnBr3 as an embodiment of the broader materials class. We show that lone pair stereochemical activity due to the Sn(2+) s(2) lone pair causes a crystallographically hidden, locally distorted state to appear upon warming, a phenomenon previously referred to as emphanisis...
September 14, 2016: Journal of the American Chemical Society
Masaki Honda, Takashi Ishimaru, Yutaka Itabashi
The red alga Gracilaria vermiculophylla is a well-known producer of prostaglandins, such as PGE2 and PGF2α. In this study, the characteristics of glycerolipids as substrates of prostaglandin production were clarified, and the lipid classes, fatty acid composition, and glycerolipid molecular species were investigated in detail. The major lipid classes were monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and sulfoquinovosyldiacylglycerol (SQDG), as well as phosphatidylcholine (PC), which accounted for 43...
2016: Journal of Oleo Science
Daniela Chmelová, Miroslav Ondrejovič
Laccases of white-rot fungi provide a promising future as a tool to be used in the field of biodegradation of synthetic dyes with different chemical structures. The aim of this study was production, characterization, and application of laccases from the white-rot fungus Ceriporiopsis subvermispora ATCC 90467 for decolorization of triphenylmethane dyes that could remain persistent in wastewater. Laccase was purified from a C. subvermispora culture by a four-step method resulting high specific activity of 2,571 U g(-1) , 88-fold higher than crude laccase...
August 31, 2016: Journal of Basic Microbiology
Jun Wang, Xi Liu, Xu-Dong Wang, Tao Dong, Xing-Yu Zhao, Dan Zhu, Yi-Yuan Mei, Guo-Hua Wu
Human milk fat-style structured triacylglycerols were produced from microalgal oil in a continuous microfluidic reactor packed with immobilized lipase for the first time. A remarkably high conversion efficiency was demonstrated in the microreactor with reaction time being reduced by 8 times, Michaelis constant decreased 10 times, the lipase reuse times increased 2.25-fold compared to those in a batch reactor. In addition, the content of palmitic acid at sn-2 position (89.0%) and polyunsaturated fatty acids at sn-1, 3 positions (81...
November 2016: Bioresource Technology
Tong Wang, Xiaosan Wang, Xingguo Wang
Interesterification or the randomization reaction changes fatty acid positional distribution and solid fat content of fats, which may consequently affect fat absorption and metabolism. It is well established that saturated fatty acids in the sn-2 position of triacylglycerols (TAG) have better digestibility and lower postprandial chylomicron clearance compared to those in the sn-1,3 positions in animal experiments. TAG structure is also shown to affect fasting lipid level and atherosclerosis in animals, but fat interesterification it has been shown to not affect fasting lipid level in human adults...
October 2016: Lipids
Bahngmi Jung, Aya Safan, Bill Batchelor, Ahmed Abdel-Wahab
This study investigates the removal of selenium (IV) from water by reductive precipitation using sodium sulfide at neutral pH. Also, it examines the application of UV light as an activating method to enhance reductive precipitation. Furthermore, this work evaluates the effects of sulfide dose and solution pH on behavior of Se(IV) reduction. Selenium was effectively removed in sulfide solution at both neutral and acidic pH. UV irradiation did not enhance removal efficiency of Se(IV) at conditions tested, but it affected solids morphology and composition...
November 2016: Chemosphere
Manuel M Bentlohner, Laura-Alice Jantke, Thomas Henneberger, Christina Fischer, Kerstin Mayer, Wilhelm Klein, Thomas F Fässler
The addition of Sn and Zn ions to [Ge9 ] clusters by reaction of [Ge9 ](4-) with SnPh2 Cl2 , ZnCp*2 (Cp*=pentamethylcyclopentadienyl), or Zn2 [HC(Ph2 P=NPh)2 ]2 is reported. The resulting Sn- and Zn-bridged clusters [(Ge9 )M(Ge9 )](q-) (M=Sn, q=4; M=Zn, q=6) display various coordination modes. The M atoms that coordinate to the open square of a C4v -symmetric [Ge9 ] cluster form strong covalent multicenter M-Ge bonds, in contrast to the M atoms coordinating to triangular cluster faces. Molecular orbital analyses show that the M atoms of the Ge9 M fragments coordinate to a second [Ge9 ] cluster with similar orbitals but in different ways...
September 19, 2016: Chemistry: a European Journal
Masahiro Nagao, Kazuyo Kobayashi, Yuta Yamamoto, Togo Yamaguchi, Akihide Oogushi, Takashi Hibino
Rechargeable proton-exchange membrane batteries that employ organic chemical hydrides as hydrogen-storage media have the potential to serve as next-generation power sources; however, significant challenges remain regarding the improvement of the reversible hydrogen-storage capacity. Here, we address this challenge through the use of metal-ion redox couples as energy carriers for battery operation. Carbon, with a suitable degree of crystallinity and surface oxygenation, was used as an effective anode material for the metal redox reactions...
February 2016: ChemElectroChem
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