scholarly journals Glucosylsterols in extracts of Euryale ferox identified by high resolution NMR and mass spectrometry.

1989 ◽  
Vol 30 (10) ◽  
pp. 1633-1637
Author(s):  
H R Zhao ◽  
S X Zhao ◽  
C Q Sun ◽  
D Guillaume
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Euryale Ferox ◽  
High Resolution Nmr

Taxus canadensis taxanes: structures and stereochemistry

1995 ◽  
Vol 73 (5) ◽  
pp. 655-665 ◽  
Author(s):  
Lolita O. Zamir ◽  
Maria E. Nedea ◽  
Zhen-Hua Zhou ◽  
Sophie Bélair ◽  
Gaétan Caron ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Natural Products ◽  
High Resolution ◽  
Taxus Canadensis ◽  
High Resolution Nmr ◽  
Nmr Techniques

The structures and stereochemistry of 14 taxanes isolated from Taxuscanadensis have been rigorously established by high-resolution NMR techniques and mass spectrometry. Taxuscanadensis is the only yew that accumulates 9-dihydro-13-acetylbaccatin III (also called 7,9-deacetylbaccatin VI) as the most abundant taxane. Five 9-dihydrotaxanes derived from the Canadian yew are novel natural products not reported in the needles of other species of yew (8–11, 14, Fig. 1). Keywords: Taxuscanadensis, Taxaceae, taxanes, 9-dihydro-13-acetylbaccatin III, taxol.

Constitution and Properties of the 8,8'-μ-(H2NO)=(1,2-C2B9H10)2-3-Co Bridged Cobaltaborane

1994 ◽  
Vol 59 (6) ◽  
pp. 1326-1336 ◽  
Author(s):  
Jaromír Plešek ◽  
Farzaneh Hosseinpour Rajabi ◽  
Veena Vangani ◽  
Jiří Fusek
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Reductive Cleavage ◽  
High Resolution Nmr ◽  
Nmr Methods ◽  
Derivatives Of

Constitution of 8,8'-μ-H2N(-O-)(1,2-C2B9H10)2-3-Co sandwich has been elucidated 17 years after its first synthesis, via high resolution NMR methods supplemented by mass spectrometry. The species gives relevant "oximes" with acetone and benzaldehyde and is quantitatively methylated to the N,N'-dimethyl derivative, which shows an interesting redox disproportionation to a triatomically bridged sandwich with a 8,8'-μ-O-CH=N(Me)- bridge between both ligands. Several other "peculiar" reactions of this dimethyl derivative are discussed. On reductive cleavage of the parent hydroxylamine the non-bridged 8-HO-8-H3N(1,2-C3B3H10)2-3-Co zwitterion is obtained. Mono-, di- and trimethylated derivatives of this non-bridged species are characterized.

Exploring the Active Compounds of Traditional Mongolian Medicine Agsirga in Intervention of Novel Coronavirus (2019-nCoV) Based on HPLC-Q-Exactive-MS/MS and Molecular Docking Method

2020 ◽  
Author(s):  
Jie Cheng ◽  
Yuchen Tang ◽  
Baoquan Bao ◽  
Ping Zhang
Keyword(s):  
Mass Spectrometry ◽  
Molecular Docking ◽  
High Resolution ◽  
Mass Spectra ◽  
High Resolution Mass Spectrometry ◽  
Structural Formula ◽  
Active Compounds ◽  
High Resolution Mass ◽  
Q Exactive ◽  
Resolution Mass

<p><a></a><a></a><a></a><a><b>Objective</b></a>: To screen all compounds of Agsirga based on the HPLC-Q-Exactive high-resolution mass spectrometry and find potential inhibitors that can respond to 2019-nCoV from active compounds of Agsirga by molecular docking technology.</p> <p><b>Methods</b>: HPLC-Q-Exactive high-resolution mass spectrometry was adopted to identify the complex components of Mongolian medicine Agsirga, and separated by the high-resolution mass spectrometry Q-Exactive detector. Then the Orbitrap detector was used in tandem high-resolution mass spectrometry, and the related molecular and structural formula were found by using the chemsipider database and related literature, combined with precise molecular formulas (errors ≤ 5 × 10<sup>−6</sup>) , retention time, primary mass spectra, and secondary mass spectra information, The fragmentation regularities of mass spectra of these compounds were deduced. Taking ACE2 as the receptor and deduced compounds as the ligand, all of them were pretreated by discover studio, autodock and Chem3D. The molecular docking between the active ingredients and the target protein was studied by using AutoDock molecular docking software. The interaction between ligand and receptor is applied to provide a choice for screening anti-2019-nCoV drugs.</p> <p><b>Result</b>: Based on the fragmentation patterns of the reference compounds and consulting literature, a total of 96 major alkaloids and stilbenes were screened and identified in Agsirga by the HPLC-Q-Exactive-MS/MS method. Combining with molecular docking, a conclusion was got that there are potential active substances in Mongolian medicine Agsirga which can block the binding of ACE2 and 2019-nCoV at the molecular level.</p>

Analysis of Squalene and Its Transformation By-Products in Latent Fingermarks by Ultrahigh-Pressure Liquid Chromatography-High Resolution Accurate Mass Orbitrap™ Mass Spectrometry

2019 ◽  
Author(s):  
Buddhika Dorakumbura ◽  
Francesco Busetti ◽  
Simon Lewis
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
High Resolution ◽  
Storage Conditions ◽  
Ultrahigh Pressure ◽  
Accurate Mass ◽  
Rational Approach ◽  
By Products ◽  
Over Time ◽  
High Resolution Accurate Mass

<p>Transformation of squalene and its by-products in fingermarks over time under different storage conditions (light, dark and underwater) was examined through ultrahigh-pressure liquid chromatography high resolution accurate mass Orbitrap™ mass spectrometry. Complications of assessing fingermark compositional variation over time using multiple samples with varying initial compositions were elucidated and a more rational approach was successfully demonstrated. Squalene was detected in all fresh natural fingermarks and the amount ranged between 0.20 to 11.32 μg/5 fingertips. A notable difference in the transformation of squalene was observed with different storage conditions, where a dark aquatic environment accelerated degradation of squalene compared to dark but dry conditions. Squalene monohydroperoxide was extremely short-lived in natural deposits while the amount of squalene epoxide was still increasing relative to the initial amount, after ageing under dark and aquatic conditions for up to 7 days. Some oxidation by-products of cholesterol were also tentatively identified, which exhibited a growth over time against their initial concentration under any of the storage condition tested. These by-products, therefore, show potential as biomarkers for targeted visualisation of aged deposits.</p>

Determination of quaternary ammonium compounds in food products by the method of ultra-performance liquid chromatography/high resolution mass-spectrometry

2020 ◽  
Vol 86 (8) ◽  
pp. 23-31
Author(s):  
V. G. Amelin ◽  
D. S. Bolshakov
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Quaternary Ammonium ◽  
High Resolution Mass Spectrometry ◽  
Food Products ◽  
Quaternary Ammonium Compounds ◽  
High Resolution Mass ◽  
Ammonium Compounds ◽  
Resolution Mass

The goal of the study is developing a methodology for determination of the residual amounts of quaternary ammonium compounds (QAC) in food products by UHPLC/high-resolution mass spectrometry after water-acetonitrile extraction of the determined components from the analyzed samples. The identification and determination of QAC was carried out on an «UltiMate 3000» ultra-high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a «maXis 4G» high-resolution quadrupole-time-of-flight mass spectrometric detector and an ion spray «ionBooster» source (Bruker Daltonics, Germany). Samples of milk, cheese (upper cortical layer), dumplings, pork, chicken skin and ground beef were used as working samples. Optimal conditions are specified for chromatographic separation of the mixture of five QAC, two of them being a mixture of homologues with a linear structure (including isomeric forms). The identification of QAC is carried out by the retention time, exact mass of the ions, and coincidence of the mSigma isotopic distribution. The limits for QAC detection are 0.1 – 0.5 ng/ml, the determination limits are 1 ng/ml for aqueous standard solutions. The determinable content of QAC in food products ranges within 1 – 100 ng/g. The results of analysis revealed the residual amount of QAC present in all samples, which confirms data of numerous sources of information about active use of QAC-based disinfectants in the meat and dairy industry. The correctness of the obtained results is verified by introduction of the additives in food products at a level of 10 ng/g for each QAC. The relative standard deviation of the analysis results does not exceed 0.18. The duration of the analysis is 30 – 40 min.

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