keyword
MENU ▼
Read by QxMD icon Read
search

Nuclear magnetic resonance

keyword
https://www.readbyqxmd.com/read/28214755/identification-of-a-new-tert-leucinate-class-synthetic-cannabinoid-in-powder-and-spice-like-herbal-incenses-methyl-2-1-5-fluoropentyl-indole-3-carbonyl-amino-3-3-dimethyl-butanoate-5f-mdmb-pica
#1
Martijn D P Risseeuw, Peter Blanckaert, Vera Coopman, Stijn Van Quekelberghe, Serge Van Calenbergh, Jan Cordonnier
A brown powder and different product packages of "spice-like" herbal incenses were analyzed using a systematic identification approach based on liquid chromatography with diode array detector (HPLC-PDA) and gas chromatography mass spectrometry (GC-MS) with computer based library search against spectral libraries. However, the most predominant compound in the methanolic sample solutions could not be identified. In order to elucidate the chemical structure, a more extensive analysis of the material was initiated using liquid chromatography mass spectrometry (LC-MS), electrospray high resolution mass spectrometry (ESI-HRMS) and (1)H, (13)C and (19)F nuclear magnetic resonance spectroscopy (NMR), which allowed the identification and characterization of the major compound as methyl 2-[[1-(5-fluoropentyl)indole-3-carbonyl]amino]-3,3-dimethyl-butanoate (5F-MDMB-PICA)...
February 4, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28214672/evaluation-of-molecular-chaperone-drug-function-regorafenib-and-%C3%AE-cyclodextrins
#2
Xiurong Hu, Mengying Sun, Yang Li, Guping Tang
Regorafenib (RG) was an oral multi-kinase inhibitor with poor water solubility. In order to enhance the drug's solubility, dissolution and bioavailability, the binary molecular chaperone drug between RG and β-cyclodetrin (β-CD) had prepared by co-crystallization. The structure of RG-β-CD was characterized by thermal analysis, powder X-ray diffraction, infrared spectroscopy and nuclear magnetic resonance. Phase-solubility study revealed the higher solubility and complexing ability of β-CDwith RG.The solubility and dissolution of RG-β-CD was significantly enhanced in pH 1...
February 7, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28213180/biochemical-composition-of-symplastic-sap-from-sugarcane-genetically-modified-to-overproduce-proline
#3
Graciele Carraro Balestro, Bruna Higashi, Sheila Mara Sanches Lopes, José Eduardo Gonçalves, Luiz Gonzaga Esteves Vieira, Arildo José Braz de Oliveira, Regina Aparecida Correia Gonçalves
Global interest in sugarcane has increased significantly in recent years because of its economic impact on sustainable energy production. The purpose of the present study was to evaluate changes in the concentrations of total sugars, amino acids, free proline, and total proteins by colorimetric analyses and nuclear magnetic resonance (NMR) to perform a metabolic profiling of a water-soluble fraction of symplastic sap in response to the constitutive expression of a mutant Δ(1)-pyrroline-5-carboxylate synthetase (P5CS) gene from Vigna aconitifolia...
February 9, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28212929/structural-analysis-of-a-homogeneous-polysaccharide-from-achatina-fulica
#4
Jie Liu, Feigneng Shang, Zengming Yang, Mingyi Wu, Jinhua Zhao
Edible snails have been widely used as a health food and medicine in many countries. In our study, a water-soluble polysaccharide (AF-1) was isolated and purified from Achatina fulica by papain enzymolysis, alcohol precipitation and strong anion exchange chromatography. Structural of the polysaccharide was analyzed and characterized by chemical and instrumental methods, such as Fourier transform infrared spectroscopy, high performance liquid chromatography, analysis of monosaccharide composition, methylation analysis, and nuclear magnetic resonance (NMR) spectroscopy ((1)H, (13)C, COSY, TOCSY, NOESY, HSQC and HMBC)...
February 14, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28212341/physicochemical-characterization-and-biological-activities-of-the-triterpenic-mixture-%C3%AE-%C3%AE-amyrenone
#5
Rosilene G S Ferreira, Walter F Silva Júnior, Valdir F Veiga Junior, Ádley A N Lima, Emerson S Lima
α-Amyrenone and β-amyrenone are triterpenoid isomers that occur naturally in very low concentrations in several oleoresins from Brazilian Amazon species of Protium (Burseraceae). This mixture can also be synthesized by oxidation of α,β-amyrins, obtained as major compounds from the same oleoresins. Using a very simple, high yield procedure, and using a readily commercially available mixture of α,β-amyrins as substrate, the binary compound α,β-amyrenone was synthesized and submitted to physico-chemical characterization using different techniques such as high-performance liquid chromatography, nuclear magnetic resonance (¹H and (13)C), mass spectrometry, scanning electron microscopy, differential scanning calorimetry, thermogravimetry and derivative thermogravimetry, and Fourier transform infrared spectroscopy (FTIR)...
February 16, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28212030/revisiting-silicalite-1-nucleation-in-clear-solution-by-electrochemical-impedance-spectroscopy
#6
Gert Brabants, Maxim Hubin, Erwin Konrad Reichel, Bernhard Jakoby, Eric Breynaert, Francis Taulelle, Johan A Martens, Christine E A Kirschhock
EIS was used to detect and investigate nucleation in silicalite-1 clear solutions. Whereas zeolite nucleation was previously assumed to be a step event, inducing a sharp discontinuity around a Si/OH ratio of 1, complex bulk conductivity measurements at elevated temperatures reveal a gradual decay of the conductivity with increased silicon concentrations. Inverse Laplace transformation of the complex conductivity allows to observe the chemical exchange phenomena governing nano-aggregate formation. At low temperatures, the fast exchange between dissociated ions and ion pairs leads to a gradual decay of the conductivity with increasing silicon content...
February 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28211639/the-use-of-on-line-heart-cutting-high-performance-liquid-chromatography-coupled-with-linear-ion-trap-mass-spectrometry-in-the-identification-of-impurities-in-vidarabine-monophosphate
#7
Hang Wang, Tongzhou Xu, Jiaojian Yuan
It is difficult to identify unknown impurities in nucleotide analogues by mass spectrometry because mass-spectrometry-incompatible mobile phases need to be used to separate the major ingredient from impurities. In this study, vidarabine monophosphate was selected, and unknown impurities were identified by online heart-cutting two-dimensional high performance liquid chromatography and linear ion trap mass spectrometry. The one dimensional reversed phase column was filled with a mobile phase containing non-volatile salt...
February 17, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28210733/super-high-energy-density-single-bonded-trigonal-nitrogen-allotrope-a-chemical-twin-of-the-cubic-gauche-form-of-nitrogen
#8
Sergey V Bondarchuk, Boris F Minaev
A new ambient-pressure metastable single-bonded 3D nitrogen allotrope (TrigN) of trigonal symmetry (space group R3[combining macron]) was calculated using density functional theory (DFT). A comprehensive characterization of this material, comprising thermodynamic, elastic, and spectral (vibrational, UV-vis absorption, and nuclear magnetic resonance) properties, was performed. Using high-throughput band structure calculation, the TrigN phase was characterized as an insulator with an indirect band gap of 2.977 eV...
February 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28209992/from-basic-apoptosis-discoveries-to-advanced-selective-bcl-2-family-inhibitors
#9
REVIEW
Avi Ashkenazi, Wayne J Fairbrother, Joel D Leverson, Andrew J Souers
Members of the B cell lymphoma 2 (BCL-2) gene family have a central role in regulating programmed cell death by controlling pro-apoptotic and anti-apoptotic intracellular signals. In cancer, apoptosis evasion through dysregulation of specific BCL-2 family genes is a recurring event; accordingly, selective inhibition of specific anti-apoptotic BCL-2 family proteins represents an exciting therapeutic opportunity. A combination of nuclear magnetic resonance (NMR)-based screening and structure-based drug design has yielded the first bona fide BCL-2 homology 3 (BH3) mimetics, including the BCL-2 and BCL-XL dual antagonist navitoclax, which is the first BCL-2 family inhibitor to show efficacy in patients with cancer...
February 17, 2017: Nature Reviews. Drug Discovery
https://www.readbyqxmd.com/read/28208765/synthesis-of-mono-and-di-glucosides-of-zearalenone-and-%C3%AE-%C3%AE-zearalenol-by-recombinant-barley-glucosyltransferase-hvugt14077
#10
Herbert Michlmayr, Elisabeth Varga, Francesca Lupi, Alexandra Malachová, Christian Hametner, Franz Berthiller, Gerhard Adam
Zearalenone (ZEN) is an estrogenic mycotoxin occurring in Fusarium-infected cereals. Glucosylation is an important plant defense mechanism and generally reduces the acute toxicity of mycotoxins to humans and animals. Toxicological information about ZEN-glucosides is limited due to the unavailability of larger amounts required for animal studies. HvUGT14077, a recently-validated ZEN-conjugating barley UDP-glucosyltransferase was expressed in Escherichia coli, affinity purified, and characterized. HvUGT14077 possesses high affinity (Km = 3 µM) and catalytic efficiency (kcat/Km = 190 s(-1)·mM(-1)) with ZEN...
February 9, 2017: Toxins
https://www.readbyqxmd.com/read/28208746/evidence-of-a-dha-signature-in-the-lipidome-and-metabolome-of-human-hepatocytes
#11
Veronica Ghini, Mattia Di Nunzio, Leonardo Tenori, Veronica Valli, Francesca Danesi, Francesco Capozzi, Claudio Luchinat, Alessandra Bordoni
Cell supplementation with bioactive molecules often causes a perturbation in the whole intracellular environment. Omics techniques can be applied for the assessment of this perturbation. In this study, the overall effect of docosahexaenoic acid (DHA) supplementation on cultured human hepatocyte lipidome and metabolome has been investigated using nuclear magnetic resonance (NMR) in combination with traditional techniques. The effect of two additional bioactives sharing with DHA the lipid-lowering effect-propionic acid (PRO) and protocatechuic acid (PCA)-has also been evaluated in the context of possible synergism...
February 8, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28208662/characterization-molecular-docking-and-in-vitro-dissolution-studies-of-solid-dispersions-of-20-s-protopanaxadiol
#12
Qi Zhang, Yiqiong Pu, Bing Wang, Yuqin Wang, Tina Tingxia Dong, Tao Guo, Tong Zhang, Zhenzhen Cai
In this study, we prepared solid dispersions (SDs) of 20(S)-protopanaxadiol (PPD) using a melting-solvent method with different polymers, in order to improve the solubility and dissolution performance of drugs with poor water solubility. The SDs were characterized via differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and molecular docking and dynamics study. DSC and PXRD results indicated that PPD crystallinity in SDs was significantly reduced, and that the majority of PPD is amorphous...
February 11, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28208606/ustiloxin-g-a-new-cyclopeptide-mycotoxin-from-rice-false-smut-balls
#13
Xiaohan Wang, Jian Wang, Daowan Lai, Weixuan Wang, Jungui Dai, Ligang Zhou, Yang Liu
Ustiloxins were cyclopeptide mycotoxins from rice false smut balls (FSBs) that formed in rice spikelets infected by the fungal pathogen Ustilaginoidea virens. To investigate the chemical diversity of these metabolites and their bioactivities, one new cyclopeptide, ustiloxin G (1), together with four known congeners-ustiloxins A (2), B (3), D (4), and F (5)-were isolated from water extract of rice FSBs. Their structures were elucidated by analyses of their physical and spectroscopic data, including ultraviolet spectrometry (UV), infrared spectroscopy (IR), 1D and 2D nuclear magnetic resonance (NMR), and high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS)...
February 10, 2017: Toxins
https://www.readbyqxmd.com/read/28208280/an-integrated-approach-to-unique-nmr-assignment-of-methionine-methyl-resonances-in-proteins
#14
Fei Yu, Jing Qiao, John Robblee, Desiree Tsao, James Anderson, Ishan Capila
The application of methyl nuclear magnetic resonance (NMR) spectroscopy in protein side-chain structural studies offers unique advantages of greater peak sensitivity, even for high-molecular-weight proteins. Traditionally, the utility of methyl NMR has often been limited by the difficulty in assigning the methyl resonances. Herein, a mass spectrometry (MS)-assisted strategy to assign the methyl resonances of methionine residues is presented. The strategy involves partially oxidizing the methionine and quantifying the oxidation level by both NMR and liquid chromatography-mass spectrometry (LC-MS)...
February 7, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28207859/differential-effects-of-silencing-crustacean-hyperglycemic-hormone-gene-expression-on-the-metabolic-profiles-of-the-muscle-and-hepatopancreas-in-the-crayfish-procambarus-clarkii
#15
Wenfeng Li, Kuo-Hsun Chiu, Yi-Chun Tien, Shih-Fu Tsai, Li-Jane Shih, Chien-Hsun Lee, Jean-Yves Toullec, Chi-Ying Lee
In order to functionally characterize the metabolic roles of crustacean hyperglycemic hormone (CHH), gene expression of CHH in the crayfish (Procambarus clarkii) was knocked down by in vivo injection of CHH double-stranded RNA (dsRNA), followed by metabolomic analysis of 2 CHH target tissues (the muscle and hepatopancreas) using nuclear magnetic resonance spectroscopy. Compared to the levels in untreated and saline-injected (SAI) animals, levels of CHH transcript, but not those of molt-inhibiting hormone (a CHH-family peptide), in the eyestalk ganglia of CHH dsRNA-injected (DSI) animals were significantly decreased at 24, 48, and 72 hour post injection (hpi), with concomitant changes in levels of CHH peptide in the sinus gland (a neurohemal organ) and hemolymph...
2017: PloS One
https://www.readbyqxmd.com/read/28207179/self-assembled-liquid-crystalline-membranes-form-supramolecular-hydrogels-via-hydrogen-bonding
#16
Youfeng Yue
Developing simple methods to organize nanoscale building blocks into ordered superstructures is a crucial step toward the practical development of nanotechnology. Bottom-up nanotechnology using self-assembly bridges the molecular and macroscopic, and can provide unique material properties, different from the isotropic characteristics of common substances. In this study, a new class of supramolecular hydrogels comprising 40 nm thick linear polymer layers sandwiched between nanolayers of self-assembled amphiphilic molecules are prepared and studied by nuclear magnetic resonance spectroscopy, scanning electronic microscopy, small angle X-ray diffraction, and rheometry...
February 16, 2017: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/28205073/multi-modality-imaging-bird-s-eye-view-from-the-2016-american-heart-association-scientific-sessions
#17
Wael A AlJaroudi, Steven G Lloyd, Farooq A Chaudhry, Fadi G Hage
This review summarizes key imaging studies that were presented in the American Heart Association Scientific Sessions 2016 related to the fields of nuclear cardiology, cardiac computed tomography, cardiac magnetic resonance, and echocardiography. This bird's eye view will inform readers about multiple studies from these different modalities. We hope that this general overview will be useful for those that did not attend the conference as well as to those that did since it is often difficult to get exposure to many abstracts at large meetings...
February 15, 2017: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
https://www.readbyqxmd.com/read/28203317/synthetic-isoliquiritigenin-inhibits-human-tongue-squamous-carcinoma-cells-through-its-antioxidant-mechanism
#18
Cuilan Hou, Wenguang Li, Zengyou Li, Jing Gao, Zhenjie Chen, Xiqiong Zhao, Yaya Yang, Xiaoyu Zhang, Yong Song
Isoliquiritigenin (ISL), a natural antioxidant, has antitumor activity in different types of cancer cells. However the antitumor effect of ISL on human tongue squamous carcinoma cells (TSCC) is not clear. Here we aimed to investigate the effects of synthetic isoliquiritigenin (S-ISL) on TSCC and elucidate the underlying mechanisms. S-ISL was synthesized and elucidated from its nuclear magnetic resonance spectrum and examined using high performance liquid chromatography. The effects of S-ISL on TSCC cells (Tca8113) were evaluated in relation to cell proliferation, apoptosis and adhesion, migration, and invasion using sulforhodamine B assay, fluorescence microscopy technique, flow cytometry (FCM) analysis, and Boyden chamber assay...
2017: Oxidative Medicine and Cellular Longevity
https://www.readbyqxmd.com/read/28202800/discovery-of-novel-pneumococcal-serotype-35d-a-natural-wcig-deficient-variant-of-serotype-35b
#19
K Aaron Geno, Jamil S Saad, Moon H Nahm
The pneumococcus (Streptococcus pneumoniae) remains a significant cause of morbidity and mortality, especially among those at the extremes of age. Its capsular polysaccharide is essential for systemic virulence. Over ninety serologically distinct pneumococcal capsular polysaccharides (serotypes) are recognized, but they are unequal in prevalence. Because antibodies against the capsule are protective, polysaccharide conjugate vaccines, which are constructed against the most prevalent serotypes, have made great reductions in pneumococcal disease caused by these serotypes...
February 15, 2017: Journal of Clinical Microbiology
https://www.readbyqxmd.com/read/28201898/a-rayleighian-approach-for-modeling-kinetics-of-ionic-transport-in-polymeric-media
#20
Rajeev Kumar, Jyoti P Mahalik, Vera Bocharova, Eric W Stacy, Catalin Gainaru, Tomonori Saito, Mallory P Gobet, Steve Greenbaum, Bobby G Sumpter, Alexei P Sokolov
We report a theoretical approach for analyzing impedance of ionic liquids (ILs) and charged polymers such as polymerized ionic liquids (PolyILs) within linear response. The approach is based on the Rayleigh dissipation function formalism, which provides a computational framework for a systematic study of various factors, including polymer dynamics, in affecting the impedance. We present an analytical expression for the impedance within linear response by constructing a one-dimensional model for ionic transport in ILs/PolyILs...
February 14, 2017: Journal of Chemical Physics
keyword
keyword
6328
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"