scholarly journals Synthesis and Conformational Assignment of N-(E)-Stilbenyloxymethylenecarbonyl-Substituted Hydrazones of Acetone ando-(m- andp-) Chloro- (nitro-) benzaldehydes by Means of and NMR Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Przemysław Patorski ◽  
Elżbieta Wyrzykiewicz ◽  
Grażyna Bartkowiak
Keyword(s):  
Nmr Spectroscopy ◽  
Spectral Data ◽  
Energy Barriers ◽  
Geometrical Isomers ◽  
Nmr Techniques ◽  
Supporting Material ◽  
Amide Conformers

Eighteen new N-(E)-stilbenyloxyalkylcarbonyl-substituted hydrazones ofortho- (meta- andpara-) chloro- (nitro-) benzaldehydes1–18and two analogous hydrazones of acetone19-20were prepared. The stereochemical behavior of1–18in dimethyl-d6sulfoxide solution has been studied by NMR and NMR techniques, using spectral data of19and20as supporting material. The E-geometrical isomers and cis-/trans-amide conformers have been found for these hydrazones. Energy barriers of isomers are reported.

Isolation of New Glycosides from Anemarrhena Asphodeloides Rhizome and Screening of their Anticancer Activity

2019 ◽  
Vol 16 (6) ◽  
pp. 474-477 ◽  
Author(s):  
Pham Van Khang ◽  
Nguyen Thi Hien Lan ◽  
Le Quang Truong ◽  
Mai Thi Minh Chau ◽  
Mai Xuan Truong ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Spectral Data ◽  
Cell Lines ◽  
Cancer Cell ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Ic50 Values ◽  
Nmr Techniques ◽  
Inhibitory Activities ◽  
Anemarrhena Asphodeloides

In this report, two new steroidal glycosides were isolated and determined from n-butanol fraction of A.asphodeloides. The structures were confirmed in comparison with the spectral data of known compounds by using different spectroscopic analysis approaches including 1D & 2D-NMR techniques and HRMS. The anti-proliferation screening against cancer cell lines A549 and HeLa indicated that compound 1 exhibited good inhibitory activities with IC50 values of 0.79 and 0.55 µg/mL, respectively.

scholarly journals NMR Spectroscopy as a Tool for Studying Asphaltene Composition

2019 ◽  
Vol 92 (3) ◽  
pp. 323-329 ◽  
Author(s):  
Jelena Parlov Vuković ◽  
Predrag Novak ◽  
Tomislav Jednačak
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Analytical Techniques ◽  
Complex Mixtures ◽  
Aggregation Process ◽  
Molecular Architecture ◽  
Valuable Data ◽  
Molecular Weights ◽  
Nmr Techniques ◽  
Oil Components

Asphaltenes are the most polar oil components with molecular weights between 500 and 1000 Da, which primarily consist of carbons and hydrogens, some heteroatoms, such as nitrogen, sulphur, oxygen and traces of nickel, vanadium and iron. Owing to their extreme complexity, it is almost impossible to completely identify all the compounds present in asphaltene samples. Various analytical techniques and approaches were used to characterize asphaltenes but their structure and composition are still a matter of thorough investigations. NMR spectroscopy can reveal useful information on asphaltene molecular architecture and aggregation process. In that respect, one- and two-dimensional NMR techniques have widely been employed. Although NMR spectra of these complex mixtures are difficult to interpret, they still can provide valuable data, especially in combination with statistical methods. Some distinctive examples of using NMR spectroscopy to study asphaltenes are given in this review.

Darstellung neuer Phosphazene und ihre Reaktionen / Preparation of new Phosphazenes and their Reactions

1972 ◽  
Vol 27 (5) ◽  
pp. 486-491 ◽  
Author(s):  
Herbert W. Roesky ◽  
Wolfgang Kloker
Keyword(s):  
Nmr Spectroscopy ◽  
Spectral Data ◽  
Mass Spectral Data ◽  
Mass Spectral

The preparations of the following compounds are described: O = PF2N = PCl2N = PCl3, O = PF2N = PCl2N = PCl2N (CH3) 2, O = PF2N=PCl2N = PCl2N (C2H5) 2, O = PF2N = PCl2N (CH3) 2, O = PF2N = PCl2N (C2H5)2, O = PF2N = PCl2N (CH3) Si (CH3)3, O = PF2N = PCl2NCS, O = PFClN = PCl2N (CH3)2, O = PFClN = PCl2N (C2H5)2, O = PFClN = PCl [N (C2H5)2]2 and O =P (C6H5) FN = PCl3. They were characterized by 1H-, 19F- and 31P-nmr spectroscopy. Analytical, ir and mass spectral data are reported. The properties of these substances are compared with the corresponding thiophosphorylderivatives.

scholarly journals Composition and Chemical Variability of Ivoirian Xylopia staudtii Leaf Oil

2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000
Author(s):  
Thierry Acafou Yapi ◽  
Jean Brice Boti ◽  
Antoine Coffy Ahibo ◽  
Sylvain Sutour ◽  
Ange Bighelli ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Nmr Spectroscopy ◽  
Essential Oils ◽  
Oil Composition ◽  
Chemical Variability ◽  
Germacrene D ◽  
Leaf Oil ◽  
Nmr Techniques ◽  
C Nmr

The chemical composition of a leaf oil sample from Ivoirian Xylopia staudtii Engler & Diels (Annonaceae) has been investigated by a combination of chromatographic [GC(RI)] and spectroscopic (GC-MS, 13C NMR) techniques. Thirty-five components that accounted for 91.8% of the whole composition have been identified. The oil composition was dominated by the furanoguaiadienes furanoguaia-1,4-diene (39.0%) and furanoguaia-1,3-diene (7.5%), and by germacrene D (17.5%). The composition of twelve other leaf oil samples demonstrated qualitative homogeneity, but quantitative variability. Indeed, the contents of the major components varied substantially: furanoguaia-1,4-diene (24.7–51.7%) and germacrene D (5.9–24.8%). The composition of X. staudtii leaf oil is close to that of X. rubescens leaf oil but varied drastically from those of the essential oils isolated from other Xylopia species. 13C NMR spectroscopy appeared as a powerful and complementary tool for analysis of sesquiterpene-rich essential oils.

scholarly journals A Phenylpropanoid and Biflavonoids from the Needles of Cephalotaxus harringtonia var. harringtonia

2017 ◽  
Vol 12 (11) ◽  
pp. 1934578X1701201 ◽  
Author(s):  
Anju Mendiratta (Nee Chugh) ◽  
Rameshwar Dayal ◽  
John P. Bartley ◽  
Graham Smith
Keyword(s):  
Nmr Spectroscopy ◽  
Oral Dose ◽  
Spectral Data ◽  
2D Nmr ◽  
Hepatoprotective Activity ◽  
X Ray Diffraction ◽  
Soluble Extract ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
First Time

A phenylpropanoid [2-(3-methoxy-4-hydroxyphenyl)-propane-1,3-diol] (1) together with four known biflavonoids namely 7, 4′, 7′″, 4′″-tetra- O-methyl amentoflavone (2); 7, 4′, 7″-tri- O-methyl amentoflavone (3); ginkgetin (4); sequoiaflavone (5) were isolated from the acetone soluble extract of needles of Cephalotaxus harringtonia var. harringtonia. Their structures were elucidated mainly on the basis of interpretation of 1D and 2D NMR spectroscopy and X-ray diffraction studies. The detailed spectral data of phenylpropanoid have been described for the first time. Ginkgetin (4) exhibited significant hepatoprotective activity in rat at 6 mg/kg oral dose level.

Elucidation of Polymer Microstructure by High Resolution NMR Spectroscopy

1967 ◽  
Vol 40 (2) ◽  
pp. 385-399 ◽  
Author(s):  
Raymond C. Ferguson
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Spectral Data ◽  
High Field ◽  
Structural Features ◽  
Polymer Microstructure ◽  
Structural Isomerism ◽  
High Resolution Nmr ◽  
Polymer Tacticity

Abstract High resolution NMR spectroscopy is proving to be a useful experimental technique for determining the microstructures of high polymers. Its major utility, aside from identifying structural features often not detectable by other methods, lies in quantitative applications. Some examples are the determination of monomer ratios in copolymers, polymer tacticity, sequence isomerism of monomer units, and other types of structural isomerism. The applicability of the method is being enhanced by continuing development of high-field spectrometers, special accessories, and new experimental techniques, and by application of computers to the analysis of spectral data.

scholarly journals Probing the interaction of U(vi) with phosphonate-functionalized mesoporous silica using solid-state NMR spectroscopy

2016 ◽  
Vol 45 (25) ◽  
pp. 10447-10458 ◽  
Author(s):  
Eva C. Uribe ◽  
Harris E. Mason ◽  
Jennifer A. Shusterman ◽  
Anthony Bruchet ◽  
Heino Nitsche
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Mesoporous Silica ◽  
Solid State Nmr ◽  
Solid State Nmr Spectroscopy ◽  
Functionalized Mesoporous Silica ◽  
Nmr Techniques ◽  
Contact Experiments

Solid-state NMR techniques combined with batch contact experiments elucidate how U(vi) binds to phosphonate-functionalized mesoporous silica.

Structure assignment of aminoconduritols by 15N NMR correlation spectroscopy; synthesis of a positional isomer of 7-deoxypancratistatin

2001 ◽  
Vol 79 (11) ◽  
pp. 1659-1667 ◽  
Author(s):  
Stefan Schilling ◽  
Uwe Rinner ◽  
Collin Chan ◽  
Ion Ghiviriga ◽  
Tomas Hudlicky
Keyword(s):  
Nmr Spectroscopy ◽  
Lewis Acid ◽  
Positional Isomer ◽  
Correlation Spectroscopy ◽  
15N Nmr ◽  
Early Stages ◽  
12 Steps ◽  
Nmr Techniques ◽  
Acid Catalyzed ◽  
Structure Assignment

A positional isomer of 7-deoxypancratistatin was synthesized in 12 steps from epoxyaziridines 4 and 5. An intermolecular opening of the aziridine rather than the epoxide in the early stages of the synthesis led to 13, which did not match the properties of tetraacetate 10 derived from 7-deoxypancratistatin. At no stage of the synthesis did standard NMR techniques, involving 1H–1H or 1H–13C coupling, prove adequate for the structure assignment. Unambiguous structure was assigned by 1H–15N correlation NMR spectroscopy as well as by the conversion of epoxide 11 to diol 29 synthesized independently by another route. Experimental and spectral details are reported for all new compounds.Key words: 15N NMR spectroscopy, iso-7-deoxypancratistatin, Lewis acid catalyzed intramolecuar opening of epoxides, aminoconduritols.

scholarly journals cis- and trans-2,5,7,9-Tetranitro-2,5,7,9-tetraazabicyclo[4,3,0]nonan-8-one and Some of its Isomers-A DFT Treatise

2020 ◽  
pp. 77-88
Author(s):  
Lemi Türker
Keyword(s):  
Spectral Data ◽  
Carbonyl Group ◽  
Density Functional ◽  
Functional Treatment ◽  
Geometrical Isomers ◽  
Cis And Trans

Some geometrical isomers of tetranitro-tetraazabicyclonanones (the titled compounds) and some of their constitutional isomers are investigated quantum chemically at the level of B3LYP/6-311++G(d,p). The constitutional isomers differ from the title compounds by the position of the carbonyl group. All the structures are nitramines (actually nitramides of organic sense). The constitutional isomers considered are capable of exhibiting proton tautomerism (keto-enol type). The tautomers have also been subjected to density functional treatment at the same level of calculation. For all the structures various electronic, energetic and spectral data have been collected and discussed.

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