Synthesis of (E,Z)-α-,(Z,Z)-α-, and (Z)-β-farnesene

1970 ◽  
Vol 23 (10) ◽  
pp. 2101 ◽  
Author(s):  
EFLJ Anet
Keyword(s):  
Mass Spectra ◽  
Phosphoryl Chloride ◽  
Minor Isomer ◽  
Liquid Phases

The three farnesenes (E,Z)-or-, (Z,Z)-or-, and (2)-P- were synthesized from (cis) (2)-nerolidol by dehydration with phosphoryl chloride in pyridine. The i.r., u.v., N.M.R., and mass spectra of the six possible α- and β-farnesenes are compared as well as their behaviour on g.1.c. on several liquid phases. The α-farnesene which predominates in apples was confirmed as being (E,E)-α-farnesene and the minor isomer, previously thought to be (E,Z)-α-farnesene, was shown to be (Z,E)-α- farnesene.

Aza analogues of pteridine. VIII. 3-Amino- from 3-Alkoxy-pyrimido[5,4-e]-as-triazin- 5-ones prepared by cyclization of 3-Ethoxy-1,2,4-triazines or other means

1974 ◽  
Vol 27 (8) ◽  
pp. 1781 ◽  
Author(s):  
DJ Brown ◽  
RK Lynn
Keyword(s):  
Hydrochloric Acid ◽  
Acetic Anhydride ◽  
Mass Spectra ◽  
Ionization Constants ◽  
Phosphoryl Chloride ◽  
Methyl Derivative ◽  
Selective Hydrolysis ◽  
Hydrolytic Product ◽  
Methanolic Hydrochloric Acid ◽  
Hydrolysis Of

Syntheses of hitherto unknown 3-aminopyrimido[5,4-e]-as-triazin-5-ones are described. One route involves selective hydrolysis of 3,5-di- or 3,5,7-tri-alkoxypyrimidotriazines at the 5-position followed by aminolysis. Another is exemplified thus: 3-ethoxy-5-methoxypyrimidotriazine (2a) is converted by methanolic hydrochloric acid into methyl 6-amino-3-ethoxy-1,2,4-triazine-5-carboxylate (3a) which then undergoes successive ammonolysis to the corresponding amide (3b), cyclization by triethyl orthoformate-acetic anhydride to 3-ethoxypyrimidotriazin-5-one (1d) and final ammonolysis to the corresponding amine (1a). The second route may be modified to furnish 3-aminopyrimidotriazine- 5,7-dione (5c) and its 6-methyl derivative (5d). Dehydration of the above amide (3b) with phosphoryl chloride gives both the corresponding nitrile (3h) and an unusual hydrolytic product, 6-amino-3- ethoxytriazin-5-one (6). The ionization constants and the u.v., N.M.R. and mass spectra are discussed.

A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

2015 ◽  
Vol 12 (1) ◽  
pp. 3910-3918 ◽  
Author(s):  
Dr Remon M Zaki ◽  
Prof Adel M. Kamal El-Dean ◽  
Dr Nermin A Marzouk ◽  
Prof Jehan A Micky ◽  
Mrs Rasha H Ahmed
Keyword(s):  
Biological Activity ◽  
Carbonyl Compounds ◽  
Mass Spectra ◽  
The Other ◽  
Pyridine Derivatives ◽  
Facile Synthesis ◽  
High Biological Activity ◽  
Basic Hydrolysis ◽  
Pyridine Carboxylate ◽  
Hydrolysis Of

 Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f  which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

In Memoriam. Professor Stefan ERNST

2015 ◽  
Vol 39 (4) ◽  
pp. 665-666
Author(s):  
Mirosław Chorazewski
Keyword(s):  
Secondary Education ◽  
Primary Education ◽  
Unexpected Death ◽  
Uranyl Compounds ◽  
Liquid Phases ◽  
German Speaking ◽  
In Memoriam ◽  
The University ◽  
Phd Thesis ◽  
Molecular Acoustics

Abstract It is with great sadness that we inform our readers about the recent death of Professor Stefan Ernst. Stefan Ernst was born in Piaśniki, Upper Silesia, on November 03, 1934, to parents of Polish-German descent. His primary education started during the war at a German-speaking school in Wirek and continued in Olesno, where he also got his secondary education. As chemistry studies were not yet available at the University ofWrocław in 1953, he started studying biology and switched to chemistry a year later. He received his master’s degree in chemistry in 1959, as one of the first graduates in that major. Then, he started his work on application of thermodynamics and molecular acoustics in investigation of liquid phases under the guidance of the Prof. Bogusława Jeżowska-Trzebiatowska. On 28 November 1967, he defended his PhD thesis entitled “Association-Dissociation Equilibria and the Structure of Uranyl Compounds in Organic Solvents” at the University of Wrocław. Professor Stefan Ernst was a linguist, a polyglot, a renowned thermodynamisist and a researcher of molecular acoustics. With great regret and shock we have learned of his sudden and unexpected death on August 03, 2014, in a hospital in Kraków.

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>

α-Methylene-β-Lactone Probe for Measuring Live-Cell Reactions of Small Molecules

2020 ◽  
Author(s):  
Lei Wang ◽  
Louis Riel ◽  
Bekim Bajrami ◽  
Bin Deng ◽  
Amy Howell ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Live Cell ◽  
Live Cells ◽  
The Novel ◽  
Proteomics Analysis ◽  
Chemical Proteomics ◽  
Tandem Mass Spectra ◽  
Modified Peptides ◽  
Covalent Probes ◽  
Ht 29

The novel use of the α-methylene-β-lactone (MeLac) moiety as a warhead of multiple electrophilic sites is reported. In this study, we demonstrate that a MeLac-alkyne is a competent covalent probe and reacts with diverse proteins in live cells. Proteomics analysis of affinity-enriched samples identifies probe-reacted proteins, resolves their modified peptides/residues, and thus characterizes probe-protein reactions. Unique methods are developed to evaluate confidence in the identification of the reacted proteins and modified peptides. Tandem mass spectra of the peptides reveal that MeLac reacts with nucleophilic cysteine, serine, lysine, threonine, and tyrosine residues, through either Michael addition or acyl addition. A peptide-centric proteomics platform, using MeLac-alkyne as the measurement probe, successfully analyzes the Orlistat selectivity in live HT-29 cells. MeLac is a versatile warhead demonstrating enormous potential to expedite the development of covalent probes and inhibitors in interrogating protein (re)activity. MeLac-empowered platforms in chemical proteomics are widely adaptable for measuring the live-cell action of reactive molecules.

Structure Revision of Protoaculeine B, a Posttranslationally Modified N-Terminal Residue in the Peptide Toxin Aculeine B

2020 ◽  
Author(s):  
Raku Irie ◽  
Kei Miyako ◽  
Satoko Matsunaga ◽  
Ryuichi Sakai ◽  
Masato Oikawa
Keyword(s):  
Mass Spectra ◽  
Chemical Reactivity ◽  
Model Compounds ◽  
Structural Revision ◽  
Structure Revision ◽  
Peptide Toxin ◽  
One Step ◽  
Marine Peptide ◽  
Synthetic Models ◽  
Long Chain

<div>Here, we newly propose the structure of protoaculeine B, an N-terminal moiety of the marine peptide toxin aculeine B, as possessing the cis-disubstituted tetrahydro-beta-carboline framework. We prepared two truncated model compounds that lack long-chain polyamine by one-step Pictet-Spengler reaction of tryptophan, and compared the NMR and mass spectra and chemical reactivity with those of natural protoaculeine B. The synthetic models reproduced the profiles of the natural product well, which was conclusive for the structural revision.</div>

Unrestrictive protein modification localization and quality control for open search of mass spectra

2018 ◽  
Author(s):  
Zhiwu An ◽  
Fuzhou Gong ◽  
Yan Fu
Keyword(s):  
Mass Spectrometry ◽  
Quality Control ◽  
Tandem Mass Spectrometry ◽  
Mass Spectra ◽  
Protein Modification ◽  
Software Tool ◽  
Tandem Mass ◽  
Simulation Data ◽  
Post Translational Modifications

We have developed PTMiner, a first software tool for automated, confident filtering, localization and annotation of protein post-translational modifications identified by open (mass-tolerant) search of large tandem mass spectrometry datasets. The performance of the software was validated on carefully designed simulation data. <br>

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