Préparation et étude des isothiocyanatoboranes halogènes

1976 ◽  
Vol 54 (13) ◽  
pp. 2135-2140 ◽  
Author(s):  
J. Dazord ◽  
H. Mongeot ◽  
H. Atchekzai ◽  
J. P. Tuchagues
Keyword(s):  
Mass Spectrometry ◽  
Mixed Species ◽  
Nmr Data ◽  
Redistribution Reactions

The mixed halide–pseudohalides BXn(NCS)3−n (n = 1 or 2) have been obtained except for X = F. Mixtures of these compounds with boron trihalide and boron triisothiocyanate are prepared by the reaction of BX3 either with metal isothiocyanates or with boron triisothiocyanate. Mass spectrometry, infrared, Raman, and 11B nmr data are reported. Rapid redistribution reactions prevent the isolation of the mixed species. Vibration spectrometry shows that boron is bonded to the nitrogen of the NCS group and not to the sulfur.

scholarly journals Two New Phomaligols from the Marine-Derived Fungus Aspergillus flocculosus and Their Anti-Neuroinflammatory Activity in BV-2 Microglial Cells

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 65
Author(s):  
Byeoung-Kyu Choi ◽  
Duk-Yeon Cho ◽  
Dong-Kug Choi ◽  
Phan Thi Hoai Trinh ◽  
Hee Jae Shin
Keyword(s):  
Nitric Oxide ◽  
Mass Spectrometry ◽  
Optical Rotation ◽  
Chemical Oxidation ◽  
Culture Broth ◽  
Membered Ring ◽  
Microglial Cells ◽  
No Production ◽  
Nmr Data ◽  
Ic50 Value

Two new phomaligols, deketo-phomaligol A (1) and phomaligol E (2), together with six known compounds (3–8) were isolated from the culture broth of the marine-derived fungus Aspergillus flocculosus. Compound 1 was first isolated as a phomaligol derivative possessing a five-membered ring. The structures and absolute configurations of the new phomaligols were determined by detailed analyses of mass spectrometry (MS), nuclear magnetic resonance (NMR) data, optical rotation values and electronic circular dichroism (ECD). In addition, the absolute configurations of the known compounds 3 and 4 were confirmed by chemical oxidation and comparison of optical rotation values. Isolated compounds at a concentration of 100 μM were screened for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Among the compounds, 4 showed moderate anti-neuroinflammatory effects with an IC50 value of 56.6 μM by suppressing the production of pro-inflammatory mediators in activated microglial cells without cytotoxicity.

scholarly journals A NEW CYTOTOXIC DOLABELLANE FROM THE INDONESIAN SOFT CORAL Anthelia sp.

2013 ◽  
Vol 13 (3) ◽  
pp. 216-220 ◽  
Author(s):  
Anggia Murni ◽  
Novriyandi Hanif ◽  
Junichi Tanaka
Keyword(s):  
Mass Spectrometry ◽  
Drug Development ◽  
Ethyl Acetate ◽  
Spectroscopic Data ◽  
Soft Coral ◽  
Ethyl Acetate Extract ◽  
2D Nmr ◽  
Cancer Drug ◽  
Nmr Data ◽  
Anti Cancer

One new dolabellane (1) and two known diterpenoids stolonidiol (2) and clavinflol B (3) have been isolated from the ethyl acetate extract of the Indonesian soft coral Anthelia sp. A new compound 1 exhibited a moderate cytotoxicity against NBT-T2 cells at 10 µg/mL, while known compounds 2 and 3 showed cytotoxicity at 1 and 0.5 µg/mL, respectively. Structure of the new compound 1 was elucidated by interpretation of NMR spectroscopic data (1D and 2D NMR data) and mass spectrometry (ESIMS data) as well as comparison with those of related ones. This finding should be useful for anti cancer drug development of the promising dolabellane-types compound.

Sur une nouvelle méthode de synthèse de δ-lactones cyclopenténiques

1986 ◽  
Vol 64 (4) ◽  
pp. 831-836 ◽  
Author(s):  
Jean Claude Caille ◽  
Michel Farnier ◽  
Roger Guilard ◽  
André Aubry ◽  
Claude Lecomte
Keyword(s):  
Mass Spectrometry ◽  
Carbon Atom ◽  
X Ray ◽  
Nmr Data ◽  
C Nmr

Synthesis of two cyclopentenic δ-lactones, 1,3,4,4a,5,6-hexahydrocyclopenta[c]pyran-1-one and its analogue possessing a cyclopentenyl group bonded to the carbon atom 4a is described, starting from the cyclopentanone or cyclopentylidene cyclopentanone. The remarkable reactivity of the tosylhydrazones allows transformation of these compounds into substituted cyclopentenes, which lead to δ-lactones by cyclization. The conditions of cyclization depend on the nature of the cyclopentanone. The structure of the two δ-lactones is established by 1H and 13C nmr data, mass spectrometry, and, in one case, by X-ray analysis.

Synthesis of metal-free tetraazaisobacteriochlorin and via template condensation of phthalogenes

2020 ◽  
Vol 24 (05n07) ◽  
pp. 878-886
Author(s):  
Semyon V. Dudkin ◽  
Takahiro Kawata ◽  
Svetlana A. Belova ◽  
Yusuke Okada ◽  
Nagao Kobayashi
Keyword(s):  
Mass Spectrometry ◽  
Quantum Chemical ◽  
2D Nmr ◽  
Metal Free ◽  
Tert Butyl ◽  
H Nmr ◽  
Nmr Data ◽  
Template Condensation ◽  
Td Dft ◽  
Low Symmetry

The indium(III) complexes of (4-(tert-butyl)phenyl)-substituted tetraazaisobacteriochlorin (TAiBC) and tetraazachlorin (TAC) were synthesized by direct template condensation of bis(4-(tert-butyl)phenyl)fumaronitrile and tetramethylsuccinonitrile using indium(III) ion as a matrix. The corresponding metal-free tetraazaisobacteriochlorin and tetraazachlorin were obtained by demetallation of their indium(III) complexes. These metal-free complexes were characterized using elemental analysis, mass-spectrometry, 1H and [Formula: see text]C{1H}NMR spectroscopy, UV-vis and MCD spectroscopy as well as DFT and TD-DFT calculations. Due to the low symmetry of the molecules, the NMR data were complex, but could be assigned by collecting 1D- and 2D NMR data and comparing with the results of quantum chemical calculations. From the position of the pyrrole proton signal (6.78 ppm), it was found that the diatropic current of TAiBC is much weaker than that of TAC, and plausibly the weakest among porphyrinoids so far reported. Absorption and MCD spectra were reasonably interpreted using the calculated absorption spectra.

scholarly journals Spirostane-type Saponins from Dracaena fragrans « Yellow Coast »

2015 ◽  
Vol 10 (1) ◽  
pp. 1934578X1501000
Author(s):  
Abdelmalek Rezgui ◽  
Anne-Claire Mitaine-Offer ◽  
Tomofumi Miyamoto ◽  
Chiaki Tanaka ◽  
Marie-Aleth Lacaille-Dubois
Keyword(s):  
Mass Spectrometry ◽  
2D Nmr ◽  
Steroidal Glycosides ◽  
Nmr Data ◽  
First Time

Three steroidal glycosides were isolated from the bark of Dracaena fragrans (L.) Ker Gawl. « Yellow Coast », and a fourth from the roots and the leaves. Their structures were characterized on the basis of extensive 1D and 2D NMR experiments and mass spectrometry, and by comparison with NMR data of the literature. These saponins have the spirostane-type skeleton and are reported in this species for the first time.

scholarly journals Etude chimique et spectroscopique du système B(SCH3)3–B(NCS)3

1979 ◽  
Vol 57 (10) ◽  
pp. 1122-1126 ◽  
Author(s):  
Habib-Raman Atchekzai ◽  
Henri Mongeot ◽  
Jacques Dazord ◽  
Jean-Pierre Tuchagues
Keyword(s):  
Mass Spectrometry ◽  
Room Temperature ◽  
Low Concentration ◽  
Nmr Data ◽  
Donor Acceptor ◽  
Set Up

Reaction of trimethylthioborate, B(SMe)3, with triisothiocyanatoborane, B(NCS)3, at room temperature gives mixtures containing B(SMe)3, the mixed compounds B(NCS)(SMe)2 and B(NCS)2(SMe) in low concentration, and association compounds. The previous compounds cannot be isolated due to equilibria being set up. Mass spectrometry, infrared and nmr data are reported. Structures involving S–B donor–acceptor bonds between the monomers are proposed for the association compounds {B(NCS)2(SMe)}2, {B(NCS)2(SMe)}2{B(NCS)3}, and {B(NCS)2(SMe)}2{B(NCS)3}2. Reaction of these compounds with trimethylamine yields Me3NB(NCS)3 and Me3NB(NCS)2(SMe). The same reaction with dimethylsulphide is incomplete and yields only Me2SB(NCS)3. Acidity strength decreases in the order B(NCS)3 > B(NCS)2(SMe) > B(NCS)(SMe)2 > B(SMe)3. This trend explains why dimerization of B(NCS)2(SMe) occurs whereas B(NCS)(SMe)2 is unassociated.

Structural units of maltenes and asphaltenes from hydrogenation of coal

1982 ◽  
Vol 47 (3) ◽  
pp. 843-852 ◽  
Author(s):  
Ivo Lang
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Physical Meaning ◽  
Average Molecular Weight ◽  
Condensed System ◽  
Vapour Phase ◽  
Aromatic System ◽  
Structural Units ◽  
Unit Structure ◽  
Nmr Data

The calculation of the unit structure weight (USW) from NMR data is discussed. A comparison with the average molecular weight (Mr) values from vapour phase osmometry and mass spectrometry measurements showed that for the coal maltenes investigated (the fraction from the coal hydrogenation product soluble in pentane), USW can be looked upon as a rapid approximation of Mr. For asphaltenes, the calculation of USW is to a high extent dependent upon the assumed arrangement of the aromatic system. For an approximation of Mr of the asphaltenes studied, the most satisfactory was the calculation of USW from parameters of the Williams method assuming the occurrence of a peri-cata-condensed system. The USW of coal hydrogenation products calculated from NMR (1H and 13C) spectra should not be attributed the physical meaning of their smallest building units.

scholarly journals A Deeper Investigation of Drug Degradation Mixtures Using a Combination of MS and NMR Data: Application to Indapamide

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1764 ◽  
Author(s):  
Cécile Palaric ◽  
Roland Molinié ◽  
Dominique Cailleu ◽  
Jean-Xavier Fontaine ◽  
David Mathiron ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Degradation Products ◽  
Multivariable Analysis ◽  
Active Pharmaceutical Ingredient ◽  
2D Nmr ◽  
Forced Degradation ◽  
Drug Degradation ◽  
Uniform Sampling ◽  
Nmr Data ◽  
Data Application

A global approach that is based on a combination of mass spectrometry (MS) and nuclear magnetic resonance (NMR) data has been developed for a complete and rapid understanding of drug degradation mixtures. We proposed a workflow based on a sample preparation protocol that is compatible to MS and NMR, the selection of the most appropriate experiments for each technique, and the implementation of prediction software and multivariable analysis method for a better interpretation and correlation of MS and NMR spectra. We have demonstrated the efficient quantification of the remaining active pharmaceutical ingredient (API). The unambiguous characterization of degradation products (DPs) was reached while using the potential of ion mobility-mass spectrometry (IM-MS) for fragment ions filtering (HDMSE) and the implementation of two-dimensional (2D) NMR experiments with the non-uniform sampling (NUS) method. We have demonstrated the potential of quantitative NMR (qNMR) for the estimation of low level DPs. Finally, in order to simultaneously monitor multi-samples, the contribution of partial least squares (PLS) regression was evaluated. Our methodology was tested on three indapamide forced degradation conditions (acidic, basic, and oxidative) and it could be easily transposed in the drug development field to assist in the interpretation of complex mixtures (stability studies, impurities profiling, and biotransformation screening).

An Extension to the JCAMP-DX Standard File Format, JCAMP-DX V.5.01

1999 ◽  
Vol 71 (8) ◽  
pp. 1549-1556 ◽  
Author(s):  
Peter Lampen ◽  
Jörg Lambert ◽  
R. J. Lancashire ◽  
R. S. McDonald ◽  
P. S. McIntyre ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Careful Consideration ◽  
File Format ◽  
Nmr Data ◽  
File Formats ◽  
Standard File Format ◽  
Good Laboratory ◽  
Year 2000

Version 5.00 of the JCAMP-DX specifications were published for NMR and Mass Spectrometry file formats in Appl. Spectrosc.47, 1093-1099, (1993) and Appl. Spectrosc.48, 1545-1552, (1994). Since publication of these protocols developments in spectroscopy have led to a large number of requests for additions for applications not originally covered. Following careful consideration, it has become apparent that a few minor modifications will significantly increase the range of possible applications.In addition, new data labels have been introduced to ensure that files are year 2000 compliant and allow for conformity with good laboratory practices (GLP). These modifications are detailed in this publication as well as examples of the official NTUPLE JCAMP-DX definition as applied to NMR data.

Preparation, isolation, and characterization of permethylated galactosides and fucosides

1999 ◽  
Vol 77 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Daniel D Asres ◽  
Hélène Perreault
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Gas Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Characterization Methods ◽  
Isolation And Characterization ◽  
Nmr Data ◽  
Layer Chromatography ◽  
Structural Aspects

Sugar analysis involving permethylation followed by methanolysis can lead to significant results, given that permethylated monosaccharide standards are available for comparison of spectral and chromatographic data. Such standards are not readily commercially available, especially the furanoside forms. This note describes the isolation and characterization of permethylated pyranoside and furanoside species of D(+)-galactose and L(-)-fucose. Separation of the isomers was optimized using a combination of column chromatography and continuous elution thin-layer chromatography (TLC). TLC, gas chromatography - mass spectrometry, and 1H nuclear magnetic resonance (NMR) spectroscopy were used as the characterization methods. The isolation of furanosides is emphasized, since no specific NMR data have been reported on those to date, while several reports have already discussed the structural aspects of pyranosides.Key words: permethylation, monosaccharide, GC-MS, TLC, NMR.

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