scholarly journals The “Wine-T1” NMR experiment for novel wine-metabolome fingerprinting with nuclear-spin relaxation

2019 ◽  
Vol 12 ◽  
pp. 02029 ◽  
Author(s):  
J.E. Herbert-Pucheta ◽  
I. Mejía-Fonseca ◽  
L.G. Zepeda-Vallejo ◽  
D. Milmo-Brittingham ◽  
G.P. Maya
Keyword(s):  
Chemical Shift ◽  
Nmr Spectra ◽  
Pulse Sequence ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
The Novel ◽  
Analytical Technique ◽  
H Nmr

In agreement with the draft resolution OENO-SCMA 17-618 at step 5 “Quantitation of glucose, malic acid, acetic acid, fumaric acid, shikimic acid and sorbic acid in wine using proton nuclear magnetic resonance spectroscopy (1H NMR)” said technique has been recently accepted within the OIV chair as a primary quantitative analytical technique for beverage analysis such as wine. However, poor chemical shift dispersion in 1H NMR spectra severely penalizes quantification within overlapped or crowded regions. To outflank said penalization and quantify metabolites in signal overcrowding situations, the novel “Wine-T1” experiment is proposed. The novel scheme comprises the addition of a second dimension, wherein the proton spin-lattice relaxation times (T1-{1H}) of each metabolite's spin-system is correlated to a chemical-shift dimension. The new experiment includes a water and ethanol signal pre-saturation module, prior to the T1 saturation-inversion recovery dimension in order to maximize signal-to-noise ratio of wine metabolome NMR spectra. “Wine-T1” pulse sequence can be adapted to all commercial spectrometers (Bruker, Varian/Agilent, Jeol) and with acquisition times in the order of minutes, it should be considered as a fast repetition method to produce a robust metabolome fingerprint that has not been described before, to the best of our knowledge.

119Sn, 13C and 1H NMR Spectra of Tris(1-butyl)stannyl D-Glucuronate

1997 ◽  
Vol 62 (8) ◽  
pp. 1169-1176 ◽  
Author(s):  
Antonín Lyčka ◽  
Jaroslav Holeček ◽  
David Micák
Keyword(s):  
Chemical Shift ◽  
Carbonyl Group ◽  
1H Nmr ◽  
Equatorial Plane ◽  
Title Compound ◽  
Nmr Spectra ◽  
Hydroxyl Groups ◽  
Carboxylic Group ◽  
H Nmr ◽  
Oxygen Atoms

The 119Sn, 13C and 1H NMR spectra of tris(1-butyl)stannyl D-glucuronate have been measured in hexadeuteriodimethyl sulfoxide, tetradeuteriomethanol and deuteriochloroform. The chemical shift values have been assigned unambiguously with the help of H,H-COSY, TOCSY, H,C-COSY and 1H-13C HMQC-RELAY. From the analysis of parameters of 119Sn, 13C and 1H NMR spectra of the title compound and their comparison with the corresponding spectra of tris(1-butyl)stannyl acetate and other carboxylates it follows that in solutions of non-coordinating solvents (deuteriochloroform) the title compound is present in the form of more or less isolated individual molecules with pseudotetrahedral environment around the central tin atom and with monodentately bound carboxylic group. The interaction of tin atom with oxygen atoms of carbonyl group and hydroxyl groups of the saccharide residue - if they are present at all - are very weak. In solutions in coordinating solvents (hexadeuteriodimethyl sulfoxide or tetradeuteriomethanol), the title compound forms complexes with one molecule of the solvent. Particles of these complexes have a shape of trigonal bipyramid with the 1-butyl substituents in equatorial plane and the oxygen atoms of monodentate carboxylic group and coordinating solvent in axial positions.

Crosslinking Density of Silk Fibroin – Rice Starch Hydrogels Modified with Trisodium Trimetaphosphate

2013 ◽  
Vol 446-447 ◽  
pp. 366-372 ◽  
Author(s):  
Anucha Racksanti ◽  
Sorapong Janhom ◽  
Sittiporn Punyanitya ◽  
Ruangsri Watanesk ◽  
Surasak Watanesk
Keyword(s):  
Silk Fibroin ◽  
Nmr Spectra ◽  
Crosslinking Density ◽  
Proton Nuclear Magnetic Resonance ◽  
Rice Starch ◽  
Infrared Spectrometry ◽  
Solution Casting ◽  
H Nmr ◽  
Nmr Spectrometry ◽  
Mb Adsorption

Silk fibroin (SF) and rice starch (RS) are both biopolymers being non-toxic, biocompatible and biodegradable which can be utilized as hydrogels. The aim of this study was to prepare the SF–RS hydrogels modified with trisodium trimetaphosphate (STMP) and determine its crosslinking density for providing a guideline for preparing better quality absorbable hydrogels. The SF–RS hydrogels modified with various percentages of STMP were prepared by solution casting at pH 12 then neutralized to pH 7. The functional groups and molecular linkages of the hydrogels were investigated by Fourier transform infrared spectrometry (FTIR) and proton nuclear magnetic resonance (1H NMR) spectrometry, respectively. Finally, the crosslinking density of the hydrogels was determined by UV/Vis spectrophotometry via the measurement of the relative amount of methylene blue (RMB) bound to the hydrogels. Results from the FTIR and 1H NMR spectra revealed that linkages within the hydrogels occurred mainly between the O–H groups of RS and the triphosphate groups of STMP. From the MB adsorption study, the crosslinking density of the SF–RS hydrogel with 1.0 %w/w STMP at the 60 min saturation time was approximately 63 %.

scholarly journals 1 H-NMR metabolomic study of whole blood from hatchling loggerhead sea turtles ( Caretta caretta ) exposed to crude oil and/or Corexit

2017 ◽  
Vol 4 (11) ◽  
pp. 171433 ◽  
Author(s):  
Stasia A. Bembenek Bailey ◽  
Jennifer N. Niemuth ◽  
Patricia D. McClellan-Green ◽  
Matthew H. Godfrey ◽  
Craig A. Harms ◽  
...  
Keyword(s):  
Crude Oil ◽  
Whole Blood ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Loggerhead Sea Turtles ◽  
Blood Samples ◽  
H Nmr ◽  
Whole Blood Samples

We used proton nuclear magnetic resonance spectroscopy ( 1 H-NMR) to evaluate metabolic impacts of environmentally relevant crude oil and Corexit exposures on the physiology of hatchling loggerhead sea turtles ( Caretta caretta ). Sample extraction and data acquisition methods for very small volume whole blood samples and sources of variation between individual hatchlings were assessed. Sixteen unclotted, whole blood samples were obtained from 7-day-old hatchlings after a 4-day cutaneous exposure to either control seawater, crude oil, Corexit 9500A or a combination of crude oil and Corexit 9500A. After extraction, one- and two-dimensional 1 H-NMR spectra of the samples were obtained, and 17 metabolites were identified and confirmed in the whole blood spectra. Variation among samples due to the concentrations of metabolites 3-hydroxybutyrate, lactate, trimethylamine oxide and propylene glycol did not statistically correlate with treatment group. However, the characterization of the hatchling loggerhead whole blood metabolome provides a foundation for future metabolomic research with sea turtles and a basis for the study of tissues from exposed hatchling sea turtles.

Preparation and properties of propargyl ether-terminated poly(imide siloxane)s and their composites

2020 ◽  
pp. 095400832095452
Author(s):  
Qing Ye ◽  
Qiaolong Yuan ◽  
Farong Huang
Keyword(s):  
Flexural Strength ◽  
Thermomechanical Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
Aromatic Diamine ◽  
The Novel ◽  
H Nmr ◽  
Chemical Structures ◽  
Propargyl Ether ◽  
Poly Imide ◽  
Thermal Stability Of

The novel propargyl ether-terminated oligo(imide siloxane)s (PTISs) based on 2,2’-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), aminopropyl-terminated polydimethylsiloxane (APPS), 4,4’-diaminodiphenylmethane (MDA) and p-aminophenyl propargyl ether (APPE) were synthesized. The chemical structures of PTISs were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR). The PTISs exhibited excellent solubility in organic solvent and had broad processing window. The T300 carbon fabric was used to reinforce the PTIS matrices and prepare the composites (T300CF/PTISs). The thermal stability of the cured PTISs was analyzed by thermogravimetric analysis (TGA). The dynamic thermal mechanical properties of the composites were measured by dynamic thermomechanical analysis (DMA). The results show that the temperature at 5% weight loss (Td5) and residual yield at 800°C (Yr800°C) of the cured PTISs in N2 increase with incorporation of the aromatic diamine, whereas the Yr800°C of the cured PTISs in air decreases with introduction of the aromatic diamine. The elasticity of the composite increases with incorporation of the aromatic diamine, and the peak temperature of loss factor for the composites are higher than 300°C. The flexural strength, tensile strength and interlaminar layer shear strength (ILSS) of the T300CF/PTIS composite display the values of 439 MPa, 427 MPa and 32 MPa at room temperature, respectively. The retention of the flexural strength and ILSS for the T300CF/PTIS composite are above 80% at 250°C.

scholarly journals Structural characteristics and electrochemical properties of sulfonated polyimide clay-based composite fabricated by a solution casting method

2019 ◽  
Vol 30 (21) ◽  
pp. 19164-19172 ◽  
Author(s):  
Nisar Ali ◽  
Farman Ali ◽  
Shaukat Saeed ◽  
Syed Sakhawat Shah ◽  
Muhammad Bilal
Keyword(s):  
Thin Films ◽  
Impedance Spectroscopy ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Solution Casting ◽  
Casting Method ◽  
Energy Devices ◽  
H Nmr ◽  
Sulfonated Polyimide ◽  
Solution Casting Method

Abstract Herein, the electrochemical and structural properties of sulfonated polyimide (SPI) clay-based composite films have been investigated. SPI reinforced with grafted sonicated clay (GSC) was fabricated via a solution casting method in the form of thin films. The as-synthesized thin films were light brown, tough, flexible and transparent. The thickness of the films were 0.109 mm and 0.056 for pristine SPI and GSC-SPI, respectively. The fabricated composite was fully investigated via Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), carbon (13C) NMR and impedance spectroscopy. The completion of the proton exchange reaction was confirmed by 1H NMR. The electrical properties of the SPI-clay based composite film were investigated by impedance spectroscopy. The conductivity was measured in a wide frequency range from room temperature to 363 K by applying an ac signal of 0.5 V. The appearance of two semicircular arcs at low and high frequency shows two conduction mechanisms with different relaxation times at the exterior and interior of the system. Bode plot also confirms the presence of two electro-active regions. The shift in the position of tanδ peaks to lower frequency region with increasing temperature shows that these relaxations are thermally deactivated. The ac conductivity of the system increased from 6.02E−10 for neat SPI to 6.61E−6 Ω−1 cm−1 for SPI-GSC composite. In conclusion, these layered silicates based conductive films have the potential to act as a polyelectrolyte membrane for fuel cell energy devices.

Nuclear magnetic resonance studies of the methylammonium hexahalotellurates

1992 ◽  
Vol 70 (3) ◽  
pp. 849-855 ◽  
Author(s):  
Mark R. MacIntosh ◽  
Marco L. H. Gruwel ◽  
Katherine N. Robertson ◽  
Roderick E. Wasylishen
Keyword(s):  
Line Shape ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Solid Phase ◽  
Variable Temperature ◽  
Spin Lattice Relaxation ◽  
Temperature Phase ◽  
H Nmr ◽  
Nmr Study ◽  
Correlated Motion

A 2H and 14N NMR study of the solid methylammonium hexahalotellurates, (MA)2TeX6 (MA = CH3ND3+ or CD3NH3+, X = Cl, Br, and I), has been undertaken to characterize the dynamics of the methylammonium (MA) ion as a function of temperature. At room temperature, the MA ion in the hexachlorotellurate (solid II) is confined to C3 jumps about the C—N axis while a small angle libration of the C—N axis is occurring. In the room temperature phase, solid I, of (MA)2TeBr6 and (MA)2TeI6 the MA ions are performing overall reorientations on the ps time scale, averaging the 2H nuclear quadrupolar interactions to zero. Variable temperature 2H NMR spin-lattice relaxation times, T1, indicate an activation energy, EA, for "isotropic" reorientations of the CH3ND3+ ion of 5.2 ± 0.5 and 2.6 ± 0.3 kJ mol−1 for X = Br and I, respectively. Deuterium T1 values for C-deuterated MA ion in the hexaiodotellurate indicate an EA for whole-ion reorientation of 3.1 ± 0.3 kJ mol−1. At any given temperature, the correlation time, τc, derived from the T1 results was found to be the same for the two deuterium-labelled hexaiodotellurates. The similarity of both the EA and the τc values implies correlated motion of the methyl and ammonium groups. The 14N T1 results for solid I of (MA)2TeI6 indicate that C—N axis motions, with an EA = 5.6 ± 0.6 kJ mol−1, are more hindered than N—D or C—D bond dynamics. The 2H NMR spectra for (MA)2TeI6 (solid II) and (MA)2TeBr6 (solids II, III, and IV) are characterized by a Pake doublet line shape. The measured peak-to-peak splittings are less than what is predicted by C3 motion about the molecular symmetry axis. It is possible to model these line shapes by postulating that C3 rotations of the methyl and ammonium groups occur as the C—N axis librates in an effective cone about the position of the static molecular axis. For (CH3ND3)2TeBr6 and (CD3NH3)3TeBr6 the peak-to-peak splittings in the 2H NMR spectra were measured as a function of temperature in solid phases II, III, and IV and were found to be similar. Finally, the 2H NMR line shape relaxation for (MA)2TeBr6 (solid III) displays an orientation dependence indicating that rotations about the C—N axis are discrete rather than diffusive in nature. For solid phase II of (MA)2TeCl6, the line shape is observed to relax isotropically, implying that continuous C3 rotations are taking place. Keywords: 2H and 14N NMR, methylammonium hexahalotellurates, molecular motion.

A simple 1H nmr conformational study of some heterocyclic azomethines

1981 ◽  
Vol 59 (8) ◽  
pp. 1205-1207 ◽  
Author(s):  
Francesco A. Bottino ◽  
Maria L. Longo ◽  
Domenico Sciotto ◽  
Michele Torre
Keyword(s):  
Hydrogen Bond ◽  
Chemical Shift ◽  
Intramolecular Hydrogen Bond ◽  
Nmr Spectra ◽  
Variable Temperature ◽  
Rotational Isomerism ◽  
Conformational Study ◽  
Pyrrole Derivatives ◽  
H Nmr ◽  
Intramolecular Hydrogen

The variable temperature 60 MHz 1H nmr spectra of some heterocyclic azomethines exclude the presence of rotational isomerism. Chemical shift values and stereospecific long-range couplings are used to establish that s-trans is the existing conformation. In the case of the pyrrole derivatives a chelated s-trans rotamer is indicated, depending on the presence of an intramolecular hydrogen bond.

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