keyword
MENU ▼
Read by QxMD icon Read
search

vcd

keyword
https://www.readbyqxmd.com/read/28777576/a-chiral-thiophene-sulfonamide-a-challenge-for-voa-calculations
#1
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
#2
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
#3
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
#4
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
#5
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
#6
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
#7
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...
July 15, 2017: Chirality
https://www.readbyqxmd.com/read/28710791/origin-of-enhanced-vcd-in-amyloid-fibril-spectra-effect-of-deuteriation-and-ph
#8
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...
July 15, 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
#9
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
https://www.readbyqxmd.com/read/28700240/the-curious-case-of-2-propyl-1h-benzimidazole-in-the-solid-state-an-experimental-and-theoretical-study
#10
María Mar Quesada-Moreno, Aurora J Cruz-Cabeza, Juan Ramón Avilés-Moreno, Pilar Cabildo, Rosa M Claramunt, Ibon Alkorta, José Elguero, Francisco J Zúñiga, Juan Jesús López-González
2-Propyl-1H-benzimidazole (2PrBzIm) is a small molecule, commercially available, which displays a curious behavior in the solid state. 2PrBzIm, although devoid of chirality by fast rotation about a single bond of the propyl group in solution, crystallizes as a conglomerate showing chiroptical properties. An exhaustive analysis of its crystal structure and a wide range of experiments monitored by vibrational circular dichroism spectroscopy eliminated all possibilities of an artifact. What remains is a new example of the unexplained phenomenon of persistent supramolecular chirality...
July 26, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28685956/cocaine-hydrochloride-structure-in-solution-revealed-by-three-chiroptical-methods
#11
Patrik Fagan, Lucie Kocourková, Michal Tatarkovič, František Králík, Martin Kuchař, Vladimír Setnička, Petr Bouř
Structure and flexibility of natural compounds determine their biological activity. In the present study, electronic circular dichroism (ECD), vibrational circular dichroism (VCD), and Raman optical activity (ROA) spectra of cocaine hydrochloride in aqueous solutions were measured and related to the structure with the aid of density functional theory (DFT) computations. Additional measurements in deuterated environment made assignment of vibrational bands easier. The results suggest that the prevalent cocaine conformation in solution differs from that adopted in hydrochloride crystal...
June 8, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28676874/chiroptical-properties-of-cryptophane-111
#12
Thierry Buffeteau, Delphine Pitrat, Nicolas Daugey, Nathalie Calin, Marion Jean, Nicolas Vanthuyne, Laurent Ducasse, Frank Wien, Thierry Brotin
The two enantiomers of cryptophane-111 (1), which possesses the most simplified chemical structure of cryptophane derivatives and exhibits the highest binding constant for xenon encapsulation in organic solution, were separated by HPLC using chiral stationary phases. The chiroptical properties of [CD(+)254]-1 and [CD(-)254]-1 were determined in CH2Cl2 and CHCl3 solutions by polarimetry, electronic circular dichroism (ECD), vibrational circular dichroism (VCD), and Raman optical activity (ROA) experiments and were compared to those of cryptophane-222 (2) derivative...
July 5, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28665467/single-center-comparison-of-the-efficacy-and-complications-of-arterial-vascular-closure-devices-in-interventional-radiology
#13
Matthew A Elmasri, Stephen T Kee, John M Moriarty, Antoinette Gomes, Edward W Lee, Justin P McWilliams
INTRODUCTION: Vascular closure devices (VCDs) are commonly used to achieve hemostasis of arterial access sites, but there is little comparative data on the variety of VCDs currently in clinical use. We reviewed the VCD experience at our institution to determine the safest and most effective VCD. MATERIALS AND METHODS: Retrospective analysis of 907 consecutive arterial procedures in interventional radiology from June 2012 to June 2014 was performed. Five VCDs were used: Angio-Seal (n = 478), FISH (n = 56), Mynx (n = 56), Perclose (n = 61), and Starclose (n = 68)...
June 20, 2017: Journal of Vascular Access
https://www.readbyqxmd.com/read/28650488/solvation-of-a-chiral-carboxylic-acid-effects-of-hydrogen-bonding-on-the-ir-and-vcd-spectra-of-%C3%AE-methoxyphenylacetic-acid
#14
Karoline Bünnemann, Christian Merten
Strong hydrogen bonding to solvent molecules can significantly alter the IR and VCD spectra of a chiral solute. This can be particularly troublesome for the determination of absolute configurations, as all spatial configurations of solute-solvent clusters need to be considered explicitly in spectra calculations. With this contribution, we aim to derive general guidelines for the explicit solvation of carboxylic acids, and characterize the solute-solvent interactions of the model compound α-methoxyphenylacetic acid (MPAA) in organic solvents of different polarity...
July 26, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28648533/recurrent-laryngeal-nerve-injury-and-swallowing-dysfunction-in-neonatal-aortic-arch-repair
#15
Kamal K Pourmoghadam, William M DeCampli, Mark Ruzmetov, James Kosko, Sami Kishawi, Michael O'Brien, Amanda Cowden, Kurt Piggott, Harun Fakioglu
BACKGROUND: We evaluated the incidence, clinical effect, and recovery rate of vocal cord dysfunction (VCD) and swallowing dysfunction in neonates undergoing aortic arch repair. METHODS: We retrospectively evaluated 101 neonates who underwent aortic arch reconstruction from 2008 to 2015. Direct flexible laryngoscopy was performed in 89 patients before initiation of postoperative oral feeding after Norwood (n = 63) and non-Norwood (n = 26) arch reconstruction. We defined VCD as immobility of vocal cords or their lack of coaptation and poor mobility...
June 22, 2017: Annals of Thoracic Surgery
https://www.readbyqxmd.com/read/28636891/comparison-of-cyclophosphamide-thalidomide-dexamethasone-to-bortezomib-cyclophosphamide-dexamethasone-as-induction-therapy-for-multiple-myeloma-patients-in-brazil
#16
Suelen Vigolo, Joice Zuckermann, Rosane Isabel Bittencourt, Lúcia Silla, Diogo André Pilger
OBJECTIVE/BACKGROUND: Chemotherapy followed by autologous hematopoietic stem cell transplantation (HSCT) remains the standard treatment for multiple myeloma (MM). Thalidomide or bortezomib may be combined with cyclophosphamide and dexamethasone, in what are known as the CTD and VCD protocols, respectively. The objective of this study was to evaluate the clinical characteristics and response rates obtained with CTD and VCD, observing whether the inclusion of bortezomib to treat MM patients in Brazil increases therapeutic efficiency...
June 15, 2017: Hematology/oncology and Stem Cell Therapy
https://www.readbyqxmd.com/read/28630251/valnoctamide-inhibits-cytomegalovirus-infection-in-developing-brain-and-attenuates-neurobehavioral-dysfunctions-and-brain-abnormalities
#17
Sara Ornaghi, Lawrence S Hsieh, Angélique Bordey, Patrizia Vergani, Michael J Paidas, Anthony N van den Pol
Cytomegalovirus (CMV) is the most common infectious cause of brain defects and neurological dysfunction in developing human babies. Due to the teratogenicity and toxicity of available CMV antiviral agents, treatment options during early development are markedly limited. Valnoctamide (VCD), a neuroactive mood stabilizer with no known teratogenic activity, was recently demonstrated to have anti-CMV potential. However, it is not known whether this can be translated into an efficacious therapeutic effect to improve CMV-induced adverse neurological outcomes...
July 19, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28622306/changes-in-uninvolved-immunoglobulins-during-induction-therapy-for-newly-diagnosed-multiple-myeloma
#18
P Ravi, S Kumar, W Gonsalves, F Buadi, M Q Lacy, R S Go, A Dispenzieri, P Kapoor, J A Lust, D Dingli, Y Lin, S J Russell, N Leung, M A Gertz, R A Kyle, P L Bergsagel, S V Rajkumar
Little is known about the impact of multiple myeloma (MM) treatment on uninvolved immunoglobulins (Ig). We identified 448 patients who received high-dose dexamethasone (HD-DEX), lenalidomide and dexamethasone (RD), bortezomib and dexamethasone (VD), bortezomib, cyclophosphamide and dexamethasone (VCD) or bortezomib, lenalidomide and dexamethasone (VRD) for newly diagnosed MM at our institution between 2000 and 2013, and who had available data on absolute lymphocyte count (ALC) and quantitative uninvolved Ig at baseline and at the end of four cycles of therapy...
June 16, 2017: Blood Cancer Journal
https://www.readbyqxmd.com/read/28622303/addition-of-cyclophosphamide-and-higher-doses-of-dexamethasone-do-not-improve-outcomes-of-patients-with-al-amyloidosis-treated-with-bortezomib
#19
E Kastritis, M Gavriatopoulou, M Roussou, D Fotiou, D C Ziogas, M Migkou, E Eleutherakis-Papaiakovou, I Panagiotidis, N Kanellias, E Psimenou, E Papadopoulou, C Pamboucas, E Manios, H Gakiopoulou, A Ntalianis, A Tasidou, S Giannouli, E Terpos, M A Dimopoulos
Bortezomib, in combination with dexamethasone (VD) or with the addition of cyclophosphamide (VCD), is highly effective in patients with amyloid light-chain (AL) amyloidosis. Currently, VCD is considered as a primary regimen for patients with AL, but it is not clear whether the addition of cyclophosphamide to VD further and significantly improves efficacy, given the substantial activity of bortezomib itself. We retrospectively compared the outcomes of 101 patients with AL amyloidosis who received VD (n=59) or VCD (n=42) in two consecutive periods...
June 16, 2017: Blood Cancer Journal
https://www.readbyqxmd.com/read/28602578/femoral-arterial-haemostasis-using-an-anchored-collagen-plug-after-percutaneous-evar-with-an-ultra-low-profile-device-prospective-audit-of-an-evolving-post-close-technique
#20
A Chaudhuri
OBJECTIVE: To present an audit of a successful "post-close" haemostatic technique using the Angio-Seal VIP vascular closure device (VCD) after percutaneous endovascular aneurysm repair (p-EVAR) using an ultra-low profile (ULP) device. METHODS: Thirty patients underwent EVAR using the Ovation device, of which 26 procedures were totally percutaneous. Data including patient habitus, procedural details, number of VCDs deployed including use of the double wire approach, and technical success/complications were prospectively recorded...
June 8, 2017: European Journal of Vascular and Endovascular Surgery
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"