Deuterium Magnetic Resonance Study Research Articles

Deuterium Magnetic Resonance Studies of Senescence-Related Changes in the Physical Properties of Rose Petal Membrane Lipids.

The physical properties of membrane lipids in senescing rose (Rosa hybrida L., cv Mercedes) petals were studied by deuterium nuclear magnetic resonance (2H-NMR) and fluorescence depolarization. All of the 2H-NMR spectra arising from deuterated dimyristoylphosphatidylcholine mixed with whole-lipid extracts from membranes of petals of different ages had a shape that is characteristic of liquid-crystalline lipid at 30[deg]C. Arrhenius plots of the moments of the 2H spectra and fluorescence depolarization values measured from 1,6-diphenyl hexatriene-labeled rose petal membrane lipid samples indicated that membrane lipid order increased with decreasing temperature as well as with increasing age of the petals. The latter trend is explained by previously observed increases in fatty acid saturation and increases in the sterol-to-phospholipid ratio that occur in rose petals during senescence. The 2H-NMR spectra obtained at 0[deg]C also contained quadrupolar splitting lines from lipid in the gel phase, confirming the occurrence of this phase in membranes from this tissue.

Deuterium magnetic resonance study of phase equilibria and membrane thickness in binary phospholipid mixed bilayers.

The gel-fluid phase equilibrium in a two-component system formed from dimyristoylphosphatidylcholine (DMPC) and distearoylphosphatidylcholine (DSPC) was investigated using solid-state wide-line 2H NMR spectroscopy. Analysis of the spectral first moments and the quantitation of gel and fluid phases by means of difference spectroscopy provided the temperature-composition phase diagrams. Phase diagrams were constructed for mixtures of perdeuterated DMPC, DMPC-d54, with DSPC and for the complementary system comprised of DMPC and perdeuterated DSPC, DSPC-d70. The gel-fluid coexistence region was found to extend over a wider range of temperature and composition for the DMPC-d54-DSPC system than for the DMPC-DSPC-d70 system. Comparison of these data with the phase diagram for the DMPC-DSPC system showed that in the gel-fluid region the fraction of lipids in the fluid phase at a given temperature and system composition decreases for the three systems in the order DMPC-d54-DSPC greater than DMPC-DSPC greater than DMPC-DSPC-d70. While the fluid fraction varies by as much as 90% among the three systems, the composition of the fluid phase, i.e., the ratio of the concentrations of the two molecules in the fluid phase, varies by about 20% over the whole temperature and system composition range. The effective acyl chain lengths of the DMPC-d54 and DSPC-d70 molecules as a function of temperature and composition in the fluid phase, when the system is all fluid or is in the gel-fluid coexistence region, were calculated from the quadrupole splittings in the axially symmetric powder patterns obtained for the all-fluid phase. The magnitudes of the coefficient of thermal expansion for both the DMPC-d54 and the DSPC-d70 molecules were smaller in the fluid phase of binary mixtures than in one-component bilayers containing either DSPC-d70 or DMPC-d54 alone. In addition, at any given temperature in the fluid phase, the increase in the acyl chain length of DMPC-d54 with increasing DSPC content of the system was smaller than the concomitant increase in the length of DSPC-d70 in mixtures with DMPC. In the entire temperature and composition range when the binary mixtures are in the all-fluid or in the gel-fluid coexistence region, the largest value obtained for the DMPC-d54 molecule in the fluid phase was smaller than the smallest value obtained for the DSPC-d70 molecule in the fluid phase. The acyl chain lengths were used to calculate the effective weighted-average thickness, d, of the fluid phase bilayer.(ABSTRACT TRUNCATED AT 400 WORDS)

ChemInform Abstract: Water Structure and Dynamics in H3PW12O40·nH2O and H3PMo12O40·nH2O: A Deuterium Magnetic Resonance Study.

ChemInformVolume 21, Issue 47 Physical Inorganic Chemistry ChemInform Abstract: Water Structure and Dynamics in H3PW12O40·nH2O and H3PMo12O40·nH2O: A Deuterium Magnetic Resonance Study. G. CHIDICHIMO, G. CHIDICHIMO Chem. Dep., Univ. Calabria, 87036 Rende, ItalySearch for more papers by this authorA. GOLEMME, A. GOLEMME Chem. Dep., Univ. Calabria, 87036 Rende, ItalySearch for more papers by this authorD. IMBARDELLI, D. IMBARDELLI Chem. Dep., Univ. Calabria, 87036 Rende, ItalySearch for more papers by this authorE. SANTORO, E. SANTORO Chem. Dep., Univ. Calabria, 87036 Rende, ItalySearch for more papers by this author G. CHIDICHIMO, G. CHIDICHIMO Chem. Dep., Univ. Calabria, 87036 Rende, ItalySearch for more papers by this authorA. GOLEMME, A. GOLEMME Chem. Dep., Univ. Calabria, 87036 Rende, ItalySearch for more papers by this authorD. IMBARDELLI, D. IMBARDELLI Chem. Dep., Univ. Calabria, 87036 Rende, ItalySearch for more papers by this authorE. SANTORO, E. SANTORO Chem. Dep., Univ. Calabria, 87036 Rende, ItalySearch for more papers by this author First published: November 20, 1990 https://doi.org/10.1002/chin.199047004AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume21, Issue47November 20, 1990 RelatedInformation

Water structure and dynamics in H3PW12O40.nH2O and H3PMo12O40.nH2O: a deuterium magnetic resonance study

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTWater structure and dynamics in H3PW12O40.nH2O and H3PMo12O40.nH2O: a deuterium magnetic resonance studyG. Chidichimo, A. Golemme, D. Imbardelli, and E. SantoroCite this: J. Phys. Chem. 1990, 94, 17, 6826–6830Publication Date (Print):August 1, 1990Publication History Published online1 May 2002Published inissue 1 August 1990https://doi.org/10.1021/j100380a052RIGHTS & PERMISSIONSArticle Views194Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (606 KB) Get e-Alerts

Molecular Dynamics and Carbon-13Relaxation in the Nematic and Smectic A, C, and B Phases of 50.7

Abstract The carbon-13 nuclear magnetic resonance spin-lattice relaxation times of the protonated ring carbonsof 4-n-pentyloxybenzylidene-4′-n-heptylaniline (50.7) have been measured in the nematic, smectic A, smectic C and smectic B phases. The results and theory presented in a recent deuterium magneticresonance study of 50.7-d 4 are used to calculate expected carbon-13 relaxation times, which are thencompared with our experimental values. The agreement is good enough to suggest that the moleculardynamics of the molecular core are reasonably well understood in the phases considered here.

Deuterium magnetic resonance study of orientation and poling in poly(vinylidene fluoride) and poly(vinylidene fluoride-co-tetrafluoroethylene)

Deuteron nuclear magnetic resonance line shapes are reported for oriented samples of poly(vinylidene fluoride) and an (80–20) copolymer of vinylidene fluoride and tetrafluoroethylene. For stretched samples the orientation of the chain axes with respect to the stretch direction is given by a Gaussian distribution of width ≊20°. The width of the distribution was slightly smaller in the more highly stretched copolymer. Surprisingly, as the magnetic field is rotated in the plane perpendicular to the stretch direction, the deuterium spectra of the poled copolymer sample do not change. The occurrence of electrical polarization in the absence of orientation dependence of the deuterium line shape indicates molecular reorientation through 180° in the copolymer.

Induced orientation of free chains in a strained rubber: A deuterium magnetic resonance study

AbstractLinear free polydimethylsiloxane (PDMS) chains are dissolved in a PDMS model network. When the system is uniaxially stretched, the free chains, as well as the network chains themselves, acquire a uniaxial orientational order, which is monitored by 2H NMR. The induced orders measured on both kinds of chains are comparable. The order is then investigated as functions of the free chain length and concentration.

ChemInform Abstract: Liquid‐Crystalline Solvents as Mechanistic Probes. Part 26. Norrish II Photolyses and Deuterium Magnetic Resonance Studies on the Solubilization Sites and Mobilities of 2‐ and sym‐Alkanones in Interdigitated and Bilayer Gel Phases of Aqueous Surfactants.

AbstractAdditionally to the title reaction shown in the scheme, the product ratios of (II)/(III) and of elemination/cyclization are also determined for the gel phases of K‐palmitate and a 1:1 mixture of K‐stearate and 1‐octadecanol.

Liquid-crystalline solvents as mechanistic probes. 26. Norrish II photolyses and deuterium magnetic resonance studies on the solubilization sites and mobilities of 2- and sym-alkanones in interdigitated and bilayer gel phases of aqueous surfactants

Liquid-crystalline solvents as mechanistic probes. 26. Norrish II photolyses and deuterium magnetic resonance studies on the solubilization sites and mobilities of 2- and sym-alkanones in interdigitated and bilayer gel phases of aqueous surfactants

Deuterium magnetic resonance studies on strained selectively deuterated elastomers

AbstractThe lineshape analysis of the 2H nuclear magnetic resonance of uniaxially strained poly(1,4‐butadiene) networks deuterated homogeneously and selectively at network junctions shows that the orientation of chain segments attached to crosslinks is larger than the average segmental orientation. In addition, it is shown that the molecular effective extension ratio of all elastically effective chains is smaller than the macroscopic extension ratio, and short chains are stretched to a higher extent than long chains. The deviation from the affine deformation behaviour and the onset of inhomogeneous deformation of individual chains takes place at the transition from the Gaussian to the non‐Gaussian network. In the Gaussian regime the segmental orientation varies with the inverse of the molecular weight of elastically effective chains in agreement with molecular theories of rubber elasticity. 2H n. m. r. spectra of a thermoplastic poly(styrene‐b‐butadiene‐b‐styrene) block copolymer carrying selectively deuterated butadiene segments at the block boundaries reveal an enhanced mobility of these segments under deformation. 2H n. m. r. experiments on amorphous segmented polyurethanes selectively deuteratured in hard and soft segments, respectively, show that the elasticity in these samples is achieved by physical crosslinks formed by very small highly mobile aggregates of hard segments dispersed in the soft phase. Within the hard domains two processes for motion due to phenyl groups in 4. 4'‐methylenebis(phenylisocyanate) units and CH2 groups in 1. 4‐butanediol units can be discriminated.

Deuterium Magnetic Resonance Study of Perdeuterated Para-Azoxy-Anisole in Solution in a Linear Nematic Polymer

Abstract A deuterium magnetic resonance (DMR) study of perdeuterated para-azoxy-anisole (PAAd14) in solution in the linear nematic thermotropic polymer DDA9-L is presented. Three concentrations are considered: 5%, 10%, 50% by weight. Information on the nature of the various phases formed with the PAA/DDA9-L mixtures is deduced from the shape of the DMR spectra. Information concerning the molecular structure, conformation and orientational order of PAA is deduced from the temperature and concentration dependence of the six quadrupolar splittings, by means of a model previously used for bulk nematic PAAd14. It is found that in the mixtures, the nematic order parameter of PAA is higher, and the molecular conformation slightly different, than in bulk. It appears that PAAd14 dissolved at low concentration (≤10% w/w) is a good DMR spin probe for the study of the DDA9 systems.

Effect of crosslinking density on the orientational order generated in strained networks: A deuterium magnetic resonance study

The orientational order generated in uniaxially strained rubbers is investigated as a function of crosslinking density. This study was carried out on two sets of rubbers; on randomly crosslinked diene networks and on model end-linked silicone rubbers. The degree of orientational order was measured by means of the deuterium n.m.r. technique; the experiments were carried out either on dissolved deuterobenzene as an n.m.r. probe (dienes) or directly on labelled polymeric chains (silicones). The induced order increases with the crosslinking density as predicted by the kinetic description of rubber elasticity. Data are related to the thermodynamics of the networks rather than to their chemical mesh size which does not accurately describe the topological structure of interest. For both sets of samples, the degree of order varies linearly with the corresponding volume fraction of polymer at swelling equilibrium.

Deuterium magnetic resonance study of the interaction between chondroitin sulfate and human plasma low density lipoproteins

[ 2H]Chondroitin sulfate was prepared by partial N -deacetylation of chondroitin sulfate ( via hydrazinolysis) followed by treatment with [ 2H 6]acetic anhydride. 2H NMR spectra of [ 2H]chondroitin sulfate in the presence of human plasma low density lipoprotein provide evidence for a soluble complex stoichiometry of 3 (and possibly 2) lipoproteins per polysaccharide molecule, and allow a rough estimation of the dissociation constant K d.

Structure of Escherichia coli membranes. Deuterium magnetic resonance studies of the phosphoglycerol head group in intact cells and model membranes

Structure of Escherichia coli membranes. Deuterium magnetic resonance studies of the phosphoglycerol head group in intact cells and model membranes

Deuterium magnetic resonance study of .alpha.,.omega.-dicarboxylic acid guests in disk micelles of varied bilayer thickness

ADVERTISEMENT RETURN TO ISSUEPREVArticleDeuterium magnetic resonance study of .alpha.,.omega.-dicarboxylic acid guests in disk micelles of varied bilayer thicknessBruce J. Forrest, Laura Hecker De Carvalho, L. W. Reeves, and Charles RodgerCite this: J. Am. Chem. Soc. 1981, 103, 1, 245–246Publication Date (Print):January 1, 1981Publication History Published online1 May 2002Published inissue 1 January 1981https://doi.org/10.1021/ja00391a069RIGHTS & PERMISSIONSArticle Views46Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (295 KB) Get e-Alerts Get e-Alerts

Deuterium magnetic resonance study of the gel and liquid crystalline phases of dipalmitoyl phosphatidylcholine

Deuterium magnetic resonance is applied to the study of the liquid crystalline and gel phases, and of the phase transition, of a multilamellar dispersion of chain perdeuterated (d62)-dipalmitoyl phosphatidylcholine/H2O. Analysis of the deuterium spectra in terms of the moments of the spectra allows one to make quantitative statements concerning the distribution of quadrupolar splittings even in complicated situations, e.g., when using perdeuterated sampled or when there are mixed phases. This analysis indicates that d62-dipalmitoyl phosphatidylcholine in excess H2O undergoes a sharp phase transition (with a width of less than 1 degree C) at approximately 37 degrees C and that there appears to be hysteresis in the phase transition of approximately 1 degree C. In the lamellar liquid crystalline phase above 37 degrees C the spectra show a number of well-resolved features whose quadrupolar splittings can be followed as the temperature is varied. The gel phase near 20 degrees C possesses a very broad, almost featureless spectrum that does not seem to support a model of the gel phase wherein the hydrocarbon chains are fully extended in the all-trans conformation. At temperatures near 0 degrees C the spectra clearly indicate that a large fraction of the lipid molecules cease the rotation about their long axes, giving a spectrum more characteristic of a rigid or solid sample. These results give a picture of the gel phase as a phase characterized by considerable hydrocarbon chain disorder near 20 degrees C and becoming a more solid-like phase near 0 degrees C. The spin-lattice relaxation time, T1, has been measured at 20 degrees C in the gel phase, and at 37 and 45 degrees C in the liquid crystalline phase. The values of T1 obtained for each of the resolvable peaks in the spectrum at 37 degrees C are compared to the values (for each peak) of T2e, the decay time of the quadrupolar echo, obtained at the same temperature. These results are discussed in terms of a simple two-motion model.

Studies in membrane processes X: A deuterium magnetic resonance study of dipalmitoyl lecithin and palmitic acid guests in magnetically-oriented hexadecyltrimethyl-ammonium bromide liquid crystalline system

The membrane phospholipid, dipalmitoyl lecithin, deuterium labelled in its fatty acyl chains, and palmitic acid-d 31 have been incorporated into the same bilayer model membrane, a lyotropic liquid crystalline hexadecyltrimethylammonium bromide mesophase which spontaneously orients in an applied magnetic field. The order parameter profiles for the lecithin and palmitic acid, and that of the host detergent are quite different indicating that the ordering of the incorporated lipids is not dictated by surrounding detergent molecules, but rather the order imposed is a function of the nature of chemical anchoring of the hydrophilic headgroups of the individual molecules at the bilayer interface. Dissimilarities in the order profiles are interpreted in terms of variations in the case of formation of random gauche conformers along the length of the acyl chains. In addition, the validity of the use of perdeuterated fatty acids as probes of the order of other membrane components is questioned. For the host detergent the relaxation rate ‘ 1 T′ 2 obtained from the line width is directly proportional to the deuterium quadrupole splitting of the —CD 2 — segments for that flexible part of the chain beyond the plateau region of constant degree of order. This indicates that for an aligned chain, the increasing motional freedom for each successive segment toward the chain end, which is linked with the increasing probability of single gauche rotations, is the motion responsible for both the decrease in degree of order and thus the increase in line width.

Deuterium magnetic resonance study of cholesteryl esters in membranes.

The ternary systems EYL:H2O (50:50 wt %) containing 1 and 5 mol % cholesteryl palmitate-d31 or 1 and 5 mol % cholesteryl palmitate-16,16,16,16-d3 have been studied. Cholesteryl palmitate-d31 gave a unique deuterium magnetic resonance spectrum corresponding to a homogeneous (delta vQ = 3 and 12 kHz) and a solid phase (deltaVQ = 38 and 118 kHz). From the characteristic spectra and spin-lattice relaxation times, a procedure for calculating the amount of each phase present in the ternary mixture is given resulting in a maximum value of homogeneously dissolved cholesteryl palmitate of 0.2 +/- 0.1 mol % and a solid fraction above 0.2 mol %. The most probable order parameter for the (-CD2)n portion of the homogeneous fraction of cholesteryl palmitate-d31 was determined from the quadrupolar splittings to be S = 0.1 which is less than one-half that of the order parameter found for the lecithin chains. Possible explanations for the diminution of the order parameter for cholesteryl ester in bilayers are discussed.

Deuterium magnetic resonance studies of the interaction of lipids with membrane proteins.

The deuterium magnetic resonance spectra of lipid-protein particles containing cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) isolated from beef heart mitochondria and the specifically deuterated lipid 1-(16,16,16-trideuteropalmitoyl)-2-palmitoleoyl phosphatidylcholine are presented. These reconstituted particles are of uniform lipid and protein content; however, the spectra clearly show two environments characterized by distinctly different residual quadrupolar splittings or order parameters. The less-ordered environment shows a splitting similar to but slightly less than that of the pure lipid alone at a given temperature. The more restricted environment appears to be induced by the presence of the protein. The amount of the restricted lipid is clearly temperature dependent with a 2- to 3-fold decrease in relative amount from 2 to 22 degrees. The rate of exchange of lipid between the free and restricted environments is slower than 10(3)/sec. The significance of these phenomena is discussed.

Conformation and reorientation of acetophenone in solution. A proton and deuterium magnetic resonance study in a nematic solvent

The deuterium spectrum of 2,3,4,5,6-pentadeuteroacetophenone dissolved in the nematogen Merck Phase V has been recorded and the quadrupolar splittings used to determine elements of the ordering matrix. Two kinds of multiple resonance experiment are used to obtain DCH3, the dipolar coupling between protons in the methyl group. In one experiment both halves of a quadrupolarsplit doublet in the deuterium spectrum are irradiated whilst observing the proton spectrum, and experiments on a sample of CH3CD2Br dissolved in Phase V are used to show the improved efficiency of this triple resonance experiment at removing proton–deuterium spin–spin coupling. In the second experiment, which is also demonstrated on the CH3CD2Br sample as well as on the acetophenone, one half of a quadrupolar-split doublet in the deuterium spectrum is irradiated whilst observing the proton-spectrum. In this case the proton spectrum is shown to yield DCH3 and also the relative sign of a quadrupole and dipolar coupling. The information obtained from these experiments is used to show that acetophenone exists predominantly in the two forms with the CCOC and phenyl ring carbons coplanar. It is also shown that the molecules reorients in the liquid crystal on each internal rotation about the phenyl—C(O) bond.