keyword
MENU ▼
Read by QxMD icon Read
search

vcd

keyword
https://www.readbyqxmd.com/read/28905189/bortezomib-and-low-dose-dexamethasone-with-or-without-continuous-low-dose-oral-cyclophosphamide-for-primary-refractory-or-relapsed-multiple-myeloma-a-randomized-phase-iii-study
#1
Martin Kropff, Martin Vogel, Guido Bisping, Rudolf Schlag, Rudolf Weide, Wolfgang Knauf, Heinrich Fiechtner, Georgi Kojouharoff, Stephan Kremers, Wolfgang E Berdel
This phase III, open-label, randomized, controlled study aimed to evaluate the benefit of adding continuous low-dose oral cyclophosphamide to bortezomib-dexamethasone in patients with primary relapsed/refractory multiple myeloma. Patients were randomized 1:1 to receive up to eight 3-week cycles of bortezomib (1.3 mg/m(2)) and dexamethasone (20 mg; VD; n = 48) or bortezomib-dexamethasone plus oral cyclophosphamide (50 mg; VCD; n = 48). Median time to progression (primary endpoint) was slightly longer in the VD versus VCD group (12...
September 14, 2017: Annals of Hematology
https://www.readbyqxmd.com/read/28902193/solid-state-vibrational-circular-dichroism-towards-molecular-recognition-chiral-metal-complexes-intercalated-in-a-clay-mineral
#2
Hisako Sato, Kenji Tamura, Kazuyoshi Takimoto, Akihiko Yamagishi
Vibrational circular dichroism (VCD) spectroscopy was applied to study chirality recognition in the interlayer space of a clay mineral. Clay intercalation compounds including two kinds of chiral molecules were prepared. Firstly a cationic metal complex, Δ- or Λ-[Ru(phen)3](2+) (phen = 1,10-phenanthroline), was ion-exchanged into sodium montmorillonite. Thereafter a neutral organic molecule, R- or S-1,1'-bi-2-naphthol (denoted as R- or S-BINOL), was co-adsorbed. The solid state VCD spectra were recorded on the hybrid compounds thus prepared...
September 13, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28901768/importance-and-difficulties-in-the-use-of-chiroptical-methods-to-assign-the-absolute-configuration-of-natural-products-the-case-of-phytotoxic-pyrones-and-furanones-produced-by-diplodia-corticola
#3
Giuseppe Mazzeo, Alessio Cimmino, Marco Masi, Giovanna Longhi, Lucia Maddau, Maurizio Memo, Antonio Evidente, Sergio Abbate
α-Pyrones and furanones are metabolites produced by Diplodia corticola, a pathogen of cork oak. Previously, the absolute configuration (AC) of diplopyrone was defined by chiroptical methods and Mosher's method. Using X-ray and chiroptical methods, the AC of sapinofuranone C was assigned, while that of the (4S,5S)-enantiomer of sapinofuranone B was established by enantioselective total synthesis. Diplofuranone A and diplobifuranylones A-C ACs are still unassigned. Here electronic and vibrational circular dichroism (ECD and VCD) and optical rotatory dispersion (ORD) spectra are reported and compared with density functional theory computations...
September 13, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28881089/intra-vs-intermolecular-hydrogen-bonding-solvent-dependent-conformational-preferences-of-a-common-supramolecular-binding-motif-from-1h-nmr-and-vcd-spectra
#4
Daniel P Demarque, Christian Merten
When predicting binding properties of small molecules or larger supramolecular aggregates, intra- and intermolecular hydrogen bonds are often considered the most important factor. Spectroscopic techniques such as 1H-NMR spectroscopy are typically utilized to characterize such binding events, but interpretation is often qualitative and follows chemical intuition. In this study, we compare the effects of intramolecular hydrogen bonding and solvation on two chiral 2,6-pyridinediyl-dialkylamides. In comparison with 1H-NMR spectroscopy, VCD spectroscopy proved to be more sensitive to conformational changes...
September 7, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28878165/mitochondrial-liver-toxicity-of-valproic-acid-and-its-acid-derivatives-is-related-to-inhibition-of-945-lipoamide-dehydrogenase
#5
Alexei P Kudin, Hafiz Mawasi, Arik Eisenkraft, Christian E Elger, Meir Bialer, Wolfram S Kunz
The liver toxicity of valproic acid (VPA) is an established side effect of this widely used antiepileptic drug, which is extremely problematic for patients with metabolic epilepsy and particularly epilepsy due to mitochondrial dysfunction. In the present report, we investigated the reason for liver mitochondrial toxicity of VPA and several acid and amide VPA analogues. While the pyruvate and 2-oxoglutarate oxidation rates of rat brain mitochondria were nearly unaffected by VPA, rat liver mitochondrial pyruvate and 2-oxoglutarate oxidation was severely impaired by VPA concentrations above 100 µM...
September 6, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28858505/synthesis-of-intrinsically-blue-colored-bis-nitronyl-nitroxide-peptidomimetic-templates-and-their-conformational-preferences-as-revealed-by-a-combined-spectroscopic-analysis
#6
Marta De Zotti, Karen Wright, Edouard d'Aboville, Antonio Toffoletti, Claudio Toniolo, Giovanna Longhi, Giuseppe Mazzeo, Sergio Abbate, Fernando Formaggio
The intrinsically blue-colored Ullman imidazolinyl nitronyl nitroxide (NN) mono-radicals have found various applications, in particular as spin probes and organic magnetic materials. Here, we present the solution-phase synthesis, extensive characterization, and conformational analysis of the first peptidomimetics with two pendant, chiral nitronyl nitroxide free radical units. Two (R)-Aic(NN) residues, where Aic(NN) is 2-amino-5-nitronylnitroxide-indan-2-carboxylic acid, have been inserted at positions i and i+3 of the pentapeptide Boc-(R)-Aic(NN)-(Ala)2-(R)-Aic(NN)-Ala-OMe and the hexapeptide Boc-[Ala-(R)-Aic(NN)-Ala]2-OMe as well...
August 31, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28857367/circular-dichroism-spectroscopy-and-dft-calculations-in-determining-absolute-configuration-and-e-z-isomers-of-conjugated-oximes
#7
Joanna E Rode, Jadwiga Frelek
The primary purpose of this work was to demonstrate the suitability of circular dichroism (CD) spectroscopy in stereochemical studies of α,β-unsaturated oximes, with particular emphasis on determination of E and Z geometry of the oxime double bond. As models for this study, O-phenyl and O-triphenylmethyl (trityl) oximes of 4-hydroxy-2-methylcyclopent-2-en-1-one were selected. These model compounds differ in both absolute configuration at C4 carbon atom and E-Z configuration of the oxime double bond. The basic dichroic technique applied was electronic circular dichroism (ECD) assisted by quantum-chemical calculations and vibrational circular dichroism (VCD) for selected cases...
August 31, 2017: Chirality
https://www.readbyqxmd.com/read/28851255/comparison-of-radial-access-versus-femoral-access-with-the-use-of-a-vascular-closure-device-for-the-prevention-of-vascular-complications-and-mortality-after-percutaneous-coronary-intervention
#8
Arno Téblick, Wies Vanderbruggen, Tom Vandendriessche, Johan Bosmans, Steven Els Frans Haine, Hielko Miljoen, Vincent Segers, Kristien Wouters, Christiaan Vrints, Marc J Claeys
BACKGROUND: Radial access (RA) and vascular closure devices (VCD) have been shown to be superior to transfemoral access (TFA) with regard to the prevention of vascular complications after percutaneous coronary intervention (PCI). OBJECTIVE: The present study evaluates whether RA is associated with less vascular complications and a lower mortality than VCD. METHODS: A total of 6999 consecutive PCI patients were studied through a single-centre prospective registry from January 2011 to August 2015...
August 29, 2017: Acta Cardiologica
https://www.readbyqxmd.com/read/28840973/absolute-configuration-of-the-ocimene-monoterpenoids-from-artemisia-absinthium
#9
Luis F Julio, Eleuterio Burgueño-Tapia, Carmen E Díaz, Nury Pérez-Hernández, Azucena González-Coloma, Pedro Joseph-Nathan
The absolute configuration (AC) of the naturally occurring ocimenes (-)-(3S,5Z)-2,6-dimethyl-2,3-epoxyocta-5,7-diene (1) and (-)-(3S,5Z)-2,6-dimethylocta-5,7-dien-2,3-diol (2), isolated from the essential oils of domesticated specimens of Artemisia absinthium, followed by vibrational circular dichroism (VCD) studies of 1, as well as from the acetonide 3 and the monoacetate 4, both derived from 2, since secondary alcohols are not the best functional groups to be present during VCD studies in solution due to intermolecular associations...
August 25, 2017: Chirality
https://www.readbyqxmd.com/read/28833487/absolute-configuration-of-an-axially-chiral-sulfonate-determined-from-its-optical-rotatory-dispersion-electronic-circular-dichroism-and-vibrational-circular-dichroism-spectra
#10
Cody L Covington, Vijay Raghavan, Jonathan P Smuts, Daniel W Armstrong, Prasad L Polavarapu
The absolute configuration (AC) of an axially chiral sulfonate (aCSO), 3,5-dimethyl-2-(naphthalen-1-yl)-6-(naphthalen-1-yl)benzenesulfonate (labeled as aCSO5), was investigated using optical rotatory dispersion (ORD), electronic circular dichroism (ECD), and vibrational circular dichroism (VCD) spectroscopies. All three methods led to the same conclusion and the AC of aCSO5 is reliably determined to be (-)-(aR, aR), or conversely (+)-(aS, aS).
August 18, 2017: Chirality
https://www.readbyqxmd.com/read/28818271/the-vestibulocochlear-bases-for-wartime-posttraumatic-stress-disorder-manifestations
#11
T A Tigno, R A Armonda, R S Bell, M A Severson
Preliminary findings based on earlier retrospective studies of 229 wartime head injuries managed by the Walter Reed Army Medical Center (WRAMC)/National Naval Medical Center (NNMC) Neurosurgery Service during the period 2003-08 detected a threefold rise in Posttraumatic Stress Disorder (PTSD) manifestations (10.45%) among Traumatic Brain Injuries (TBI) having concomitant vestibulocochlear injuries compared to 3% for the TBI group without vestibulo-cochlear damage (VCD), prompting the authors to undertake a more focused study of the vestibulo-auditory pathway in explaining the development of posttraumatic stress disorder manifestations among the mostly Blast-exposed head-injured...
September 2017: Medical Hypotheses
https://www.readbyqxmd.com/read/28777576/a-chiral-thiophene-sulfonamide-a-challenge-for-voa-calculations
#12
Joanna E Rode, Jan Cz Dobrowolski, Krzysztof Lyczko, Aleksandra Wasiewicz, Dorota Kaczorek, Robert Kawęcki, Grzegorz Zajac, Malgorzata Baranska
Two enantiomers of 2-methyl-N-(1-thien-2-ylethyl)propane-2-sulfonamide (TSA), were synthesized and their VCD, ROA, IR, and Raman spectra were registered. The solved (S)-TSA X-ray structure shows a disorder connected to the presence of two TSA conformers differing by a slight rotation of the thiophene ring. Two molecules in the units cell of monoclinic P21 crystal form a net of NH∙∙∙OS and C*H∙∙∙OS hydrogen bonds. Out of a series of computational levels tested to interpret the spectra, the B3LYP functional combined with the def2TZVP basis set satisfactorily reproduces the experimental VCD and ROA spectra...
August 4, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28771833/chirality-sensing-of-bioactive-compounds-with-amino-alcohol-unit-via-circular-dichroism
#13
Marcin Górecki, Grażyna Groszek, Jadwiga Frelek
The aim of the present work was to test various chiroptical techniques, including in particular the in situ dirhodium methodology, to assign the absolute configuration of 1,2- and 1,3-amino alcohols. As models, we selected mainly compounds that have both an additional strongly absorbing and interfering chromophoric system and application in medicinal chemistry. Determination of the absolute configuration (AC) of the tested molecules such as cinchona alkaloids, Tamiflu, and others was carried out using a combination of electronic and vibrational circular dichroism (ECD, VCD) spectroscopy...
August 3, 2017: Chirality
https://www.readbyqxmd.com/read/28767061/bifurcatriol-a-new-antiprotozoal-acyclic-diterpene-from-the-brown-alga-bifurcaria-bifurcata
#14
Vangelis Smyrniotopoulos, Christian Merten, Marcel Kaiser, Deniz Tasdemir
Linear diterpenes that are commonly found in brown algae are of high chemotaxonomic and ecological importance. This study reports bifurcatriol (1), a new linear diterpene featuring two stereogenic centers isolated from the Irish brown alga Bifurcariabifurcata. The gross structure of this new natural product was elucidated based on its spectroscopic data (IR, 1D and 2D-NMR, HRMS). Its absolute configuration was identified by experimental and computational vibrational circular dichroism (VCD) spectroscopy, combined with the calculation of (13)C-NMR chemical shielding constants...
August 2, 2017: Marine Drugs
https://www.readbyqxmd.com/read/28745019/identifying-cancer-drug-regimens-in-french-health-insurance-database-an-application-in-multiple-myeloma-patients
#15
Aurore Palmaro, Martin Gauthier, Fabien Despas, Maryse Lapeyre-Mestre
PURPOSE: There is no consensus on how to handle complex drug combinations of cancer drugs through medico-administrative databases. Our objective was to develop an algorithm for identifying the nature and patterns of treatment lines in a cohort of newly treated multiple myeloma patients. METHODS: A cohort of multiple myeloma patients starting a first treatment line was built using both ambulatory and hospital data from regional data of the French national healthcare system database (SNIIRAM)...
July 25, 2017: Pharmacoepidemiology and Drug Safety
https://www.readbyqxmd.com/read/28742349/exploring-the-sponge-consortium-plakortis-symbiotica-xestospongia-deweerdtae-as-a-potential-source-of-antimicrobial-compounds-and-probing-the-pharmacophore-for-antituberculosis-activity-of-smenothiazole-a-by-diverted-total-synthesis
#16
Carlos Jiménez-Romero, Joanna E Rode, Yeiry M Pérez, Scott G Franzblau, Abimael D Rodríguez
Fractionation of the bioactive CHCl3-MeOH (1:1) extracts obtained from two collections of the sponge consortium Plakortis symbiotica-Xestospongia deweerdtae from Puerto Rico provided two new plakinidone analogues, designated as plakinidone B (2) and plakinidone C (3), as well as the known plakinidone (1), plakortolide F (4), and smenothiazole A (5). The structures of 1-5 were characterized on the basis of 1D and 2D NMR spectroscopic, IR, UV, and HRMS analysis. The absolute configurations of plakinidones 2 and 3 were established through chemical correlation methods, VCD/ECD experiments, and spectroscopic data comparisons...
July 25, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28724912/annual-variations-of-monsoon-and-drought-detected-by-gps-a-case-study-in-yunnan-china
#17
Weiping Jiang, Peng Yuan, Hua Chen, Jianqing Cai, Zhao Li, Nengfang Chao, Nico Sneeuw
The Global Positioning System (GPS) records monsoonal precipitable water vapor (PWV) and vertical crustal displacement (VCD) due to hydrological loading, and can thus be applied jointly to diagnose meteorological and hydrological droughts. We have analyzed the PWV and VCD observations during 2007.0-2015.0 at 26 continuous GPS stations located in Yunnan province, China. We also obtained equivalent water height (EWH) derived from the Gravity Recovery And Climate Experiment (GRACE) and precipitation at these stations with the same period...
July 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28710844/reliable-hplc-separation-vibrational-circular-dichroism-spectra-and-absolute-configurations-of-isoborneol-enantiomers
#18
Rui-Qi Gao, Jun Fan, Qi Tan, Dong Guo, Tao Chen, Ru-Jian He, Dan Li, Hui Zhang, Wei-Guang Zhang
Resolution of chiral compounds has played an important role in the pharmaceutical field, involving detailed studies of pharmacokinetics, physiological, toxicological, and metabolic activities of enantiomers. Herein, a reliable method by high-performance liquid chromatography (HPLC) coupled with an optical rotation detector was developed to separate isoborneol enantiomers. A cellulose tris(3, 5-dimethylphenylcarbamate)-coated chiral stationary phase showed the best separation performance for isoborneol enantiomers in the normal phase among four polysaccharide chiral packings...
September 2017: Chirality
https://www.readbyqxmd.com/read/28710791/origin-of-enhanced-vcd-in-amyloid-fibril-spectra-effect-of-deuteriation-and-ph
#19
Markéta Pazderková, Tomáš Pazderka, Maruda Shanmugasundaram, Rina K Dukor, Igor K Lednev, Laurence A Nafie
Supramolecular chirality of amyloid fibrils, protein aggregates related to many neurodegenerative diseases, is a remarkable property associated with fibril structure and polymorphism. Since its discovery almost 10 years ago there is still little understanding of this phenomenon, including the cause of the highly enhanced vibrational circular dichroism (VCD) intensity arising from fibril supramolecular chirality. In this study, VCD spectra, enhanced by filament supramolecular chirality, are presented for lysozyme and insulin fibrils above and below pH 2 and after deuterium exchange, above and below pD 2...
September 2017: Chirality
https://www.readbyqxmd.com/read/28700810/to-avoid-chasing-incorrect-chemical-structures-of-chiral-compounds-raman-optical-activity-and-vibrational-circular-dichroism-spectroscopies
#20
Prasad L Polavarapu, Cody L Covington, Vijay Raghavan
A chemical structure (CS) identifies the connectivities between atoms, and the nature of those connections, for a given elemental composition. For chiral molecules, in addition to the identification of CS, the identification of the correct absolute configuration (AC) is also needed. Several chiral natural products are known whose CSs were initially mis-identified and later corrected, and these errors were often discovered during the total synthesis of natural products. In this work, we present a new and convenient approach that can be used with Raman optical activity (ROA) and vibrational circular dichroism (VCD) spectroscopies, to distinguish between the correct and incorrect CSs of chiral compounds...
July 12, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
keyword
keyword
66110
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"