The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Jean Bézard - One of the best experts on this subject based on the ideXlab platform.
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Separation of monoacylglycerol enantiomers as urethane derivatives by chiral-phase high performance liquid chromatography
Journal of Liquid Chromatography & Related Technologies, 1994Co-Authors: B.g. Semporé, Jean BézardAbstract:Abstract High Performance Liquid Chromatographic (HPLC) separation of monoacylglycerol enantiomers, as [di-]3,5-dinitrophenyl isocyanate (methane) derivatives, was carried out on a chiral column containing N-(R)-1-(α-naphthyl)ethylarninocarbonyl-(S)-valine chemically bound to γ-aminopropyl silanized silica as stationary phase. In addition to the separation of commercial rac-, sn-2- and sn-3-Monoacylglycerols with saturated and unsaturated acyl groups, the analysis of natural source mixtures of sn-1(3)-Monoacylglycerols obtained by partial chemical and enzymatic deacylation, was reported. These natural source Monoacylglycerols, originated from peanut and cottonseed oil triacylglycerols isolated by combination of argentation-TLC and reversed-phaseHPLC. They were first fractionated by HPLC according to chain length, unsaturution and partially according to positional isomerism (sn-2- separated from sn-1(3)-monoacylglycerol) and then derivatized. An isocratic elution at ambient temperature with mixtures of hex...
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separation of Monoacylglycerols by reversed phase high performance liquid chromatography
Journal of Chromatography A, 1992Co-Authors: B.g. Semporé, Jean BézardAbstract:Abstract Reversed-phase high-performance liquid chromatography on a thermostated octadecylsilyl column was used to separate complex mixtures of monoacyglycerols formed by chemical deacylation of natural triacyclycerols. Acetonitrile-water mixtures were used for elution of the underivatized Monoacylglycerols and a different refractometer was used for their detection. The order of elution of Monoacylglycerols in complex mixtures varies as a function of the chain length, unsaturation, positional isomerism, analysis temperature and eluent water concentration. The peak areas were representative of the amounts of Monoacylglycerols detected. The method can be applied to compositional analysis and to the collection of non-contaminated fractions for further stereospecific analysis.
Koen Dewettinck - One of the best experts on this subject based on the ideXlab platform.
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Monoacylglycerols in dairy recombined cream i the effect on milk fat crystallization
Food Research International, 2013Co-Authors: Eveline Fredrick, Kim Moens, Bart Heyman, Sabine Fischer, Paul Van Der Meeren, Koen DewettinckAbstract:Abstract The effect of Monoacylglycerols (rich in oleic acid, stearic acid or lauric acid) on milk fat crystallization in recombined cream is examined using differential scanning calorimetry to study crystallization kinetics, nuclear magnetic resonance to measure solid fat content during storage and interfacial tension analyses to analyze interfacial properties. The long-chain saturated Monoacylglycerols (stearic acid) form upon cooling a two-dimensional crystal at the interface, called chain crystallization, which induces interfacial heterogeneous nucleation. Also, the crystal growth and α–β′ polymorphic transition were accelerated. On the contrary, long-chain unsaturated Monoacylglycerols (oleic acid) didn't affect the crystallization behavior while mid-chain saturated Monoacylglycerols (lauric acid) showed intermediate behavior. None of the Monoacylglycerols influenced the solid fat content after storage for 5 days at 5 °C. The observed differences in nucleation mechanism and crystallization kinetics may influence the microstructural arrangement of the milk fat inside the fat globules and consequently the partial coalescence rate and hence the whipping properties of recombined cream.
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Monoacylglycerols in dairy recombined cream ii the effect on partial coalescence and whipping properties
Food Research International, 2013Co-Authors: Eveline Fredrick, Kim Moens, Bart Heyman, Sabine Fischer, Paul Van Der Meeren, Tom Verwijlen, Paula Moldenaers, Koen DewettinckAbstract:Abstract The influence of unsaturated (rich in oleic acid, MAG-O) and saturated (rich in stearic acid, MAG-S) Monoacylglycerols on the shear-induced partial coalescence and on the whipping properties of recombined cream was studied at different concentrations. MAG-O reduces the churning time and the whipping time, lowers the overrun and serum loss and increases the firmness of the whipped cream. The exact opposite effects were observed upon the addition of MAG-S. Protein load analyses, interfacial tension measurements and interfacial rheology experiments were carried out to elucidate the mechanism behind the diverging effects of these Monoacylglycerols. The long-chain saturated MAGs behaved as a solid at the oil–water interface while its unsaturated counterpart appeared to be in the liquid state. The occurrence of chain crystallization and subsequent interfacial heterogeneous nucleation appeared to play a decisive role in the stability of RCs towards partial coalescence.
Valentina Ruizgutierrez - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of molecular species of Monoacylglycerols diacylglycerols and triacylglycerols in human very low density lipoproteins by reversed phase liquid chromatography
Journal of Chromatography B, 2003Co-Authors: Javier S Perona, Valentina RuizgutierrezAbstract:Abstract The aim of the present study was to investigate the applicability of a previously developed method for the analysis of triacylglycerol molecular species to the simultaneous determination of triacylglycerols, diacylglycerols and Monoacylglycerols of human very-low-density lipoproteins (VLDL). Ten elderly women were recruited for the study. Blood was obtained in fasting conditions and VLDL were isolated by ultracentrifugation. Neutral lipids were separated by solid-phase extraction and were subsequently injected on a reversed-phase HPLC system, with an elution system composed of acetone in acetonitrile. The method allowed the separation of four Monoacylglycerols, 18 diacylglycerols and 24 triacylglycerols, including the resolution of positional isomers of diacylglycerols. Monoacylglycerols were composed of oleic, linoleic, palmitic and stearic acids. The major diacylglycerols were 1,2-dilinoleoyl-glycerol and 1,3-dilinoleoyl-glycerol (14.24±1.02 and 17.93±1.42%, respectively). The main triacylglycerols quantified were dioleoyl-stearoyl-glycerol (OOS), oleoyl-dipalmitoyl-glycerol (OPP), trilinoleoyl-glycerol (LLL) and linoleoyl-distearoyl-glycerol (LSS), accounting for 11.25±2.15, 10.14±2.05, 9.35±2.30 and 8.56±1.56%, respectively. An inverse relationship between polarity and fatty acid disappearance from triacylglycerols (r2=0.82, P
B.g. Semporé - One of the best experts on this subject based on the ideXlab platform.
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Separation of monoacylglycerol enantiomers as urethane derivatives by chiral-phase high performance liquid chromatography
Journal of Liquid Chromatography & Related Technologies, 1994Co-Authors: B.g. Semporé, Jean BézardAbstract:Abstract High Performance Liquid Chromatographic (HPLC) separation of monoacylglycerol enantiomers, as [di-]3,5-dinitrophenyl isocyanate (methane) derivatives, was carried out on a chiral column containing N-(R)-1-(α-naphthyl)ethylarninocarbonyl-(S)-valine chemically bound to γ-aminopropyl silanized silica as stationary phase. In addition to the separation of commercial rac-, sn-2- and sn-3-Monoacylglycerols with saturated and unsaturated acyl groups, the analysis of natural source mixtures of sn-1(3)-Monoacylglycerols obtained by partial chemical and enzymatic deacylation, was reported. These natural source Monoacylglycerols, originated from peanut and cottonseed oil triacylglycerols isolated by combination of argentation-TLC and reversed-phaseHPLC. They were first fractionated by HPLC according to chain length, unsaturution and partially according to positional isomerism (sn-2- separated from sn-1(3)-monoacylglycerol) and then derivatized. An isocratic elution at ambient temperature with mixtures of hex...
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separation of Monoacylglycerols by reversed phase high performance liquid chromatography
Journal of Chromatography A, 1992Co-Authors: B.g. Semporé, Jean BézardAbstract:Abstract Reversed-phase high-performance liquid chromatography on a thermostated octadecylsilyl column was used to separate complex mixtures of monoacyglycerols formed by chemical deacylation of natural triacyclycerols. Acetonitrile-water mixtures were used for elution of the underivatized Monoacylglycerols and a different refractometer was used for their detection. The order of elution of Monoacylglycerols in complex mixtures varies as a function of the chain length, unsaturation, positional isomerism, analysis temperature and eluent water concentration. The peak areas were representative of the amounts of Monoacylglycerols detected. The method can be applied to compositional analysis and to the collection of non-contaminated fractions for further stereospecific analysis.
Christopher J. Fowler - One of the best experts on this subject based on the ideXlab platform.
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A Reversible and Selective Inhibitor of Monoacylglycerol Lipase Ameliorates Multiple Sclerosis
Angewandte Chemie, 2014Co-Authors: Gloria Hernández-torres, Mariateresa Cipriano, Erika Hedén, Emmelie Björklund, Ángeles Canales, Debora Zian, Ana Feliú, Miriam Mecha, Carmen Guaza, Christopher J. FowlerAbstract:Monoacylglycerol lipase (MAGL) is the enzyme responsible for the inactivation of the endocannabinoid 2-arachidonoylglycerol (2-AG). MAGL inhibitors show analgesic and tissue-protecting effects in s ...
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Monoacylglycerol lipase – a target for drug development?
British Journal of Pharmacology, 2012Co-Authors: Christopher J. FowlerAbstract:The endocannabinoid (eCB) system is involved in processes as diverse as control of appetite, perception of pain and the limitation of cancer cell growth and invasion. The enzymes responsible for eCB breakdown are attractive pharmacological targets, and fatty acid amide hydrolase inhibitors, which potentiate the levels of the eCB anandamide, are now undergoing pharmaceutical development. ‘Drugable’ selective inhibitors of monoacylglycerol lipase, a key enzyme regulating the levels of the other main eCB, 2-arachidonoylglycerol, were however not identified until very recently. Their availability has resulted in a large expansion of our knowledge concerning the pharmacological consequences of monoacylglycerol lipase inhibition and hence the role(s) played by the enzyme in the body. In this review, the pharmacology of monoacylglycerol lipase will be discussed, together with an analysis of the therapeutic potential of monoacylglycerol lipase inhibitors as analgesics and anticancer agents.
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A novel assay for monoacylglycerol hydrolysis suitable for high-throughput screening
Analytical Biochemistry, 2006Co-Authors: Johan Brengdahl, Christopher J. FowlerAbstract:Abstract A simple assay for monoacylglycerol hydrolysis suitable for high-throughput screening is described. The assay uses [3H]2-oleoylglycerol as substrate, with the tritium label in the glycerol part of the molecule and the use of phenyl sepharose gel to separate the hydrolyzed product ([3H]glycerol) from substrate. Using cytosolic fractions derived from rat cerebella as a source of hydrolytic activity, the assay gives the appropriate pH profile and sensitivity to inhibition with compounds known to inhibit hydrolysis of this substrate. The assay could also be adapted to a 96-well plate format, using C6 cells as the source of hydrolytic activity. Thus the assay is simple and appropriate for high-throughput screening of inhibitors of monoacylglycerol hydrolysis.
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Inhibition of monoacylglycerol lipase and fatty acid amide hydrolase by analogues of 2-arachidonoylglycerol.
British Journal of Pharmacology, 2004Co-Authors: Nazdar Ghafouri, Gunnar Tiger, Raj K. Razdan, Anu Mahadevan, Roger G. Pertwee, Billy R. Martin, Christopher J. FowlerAbstract:Inhibition of monoacylglycerol lipase and fatty acid amide hydrolase by analogues of 2-arachidonoylglycerol
