scholarly journals Detection of L-Proline-Catalyzed Michael Addition Reaction in Model Biomembrane

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Masanori Hirose ◽  
Shigenori Sugisaki ◽  
Keishi Suga ◽  
Hiroshi Umakoshi
Keyword(s):  
Michael Addition ◽  
Reaction Rate ◽  
Phase State ◽  
Addition Reaction ◽  
Michael Addition Reaction ◽  
Membrane Systems ◽  
Liposome Membrane ◽  
Reaction Rate Constants ◽  
Plausible Model ◽  
Kinetics Of

A method to detect the L-proline- (L-Pro-) catalyzed Michael addition reaction in model biomembranes has been established, using N-[p(2-benzimidazolyl)phenyl]maleimide and acetone as reactants. The effect of liposome membranes on this reaction was kinetically analyzed using fluorescence spectroscopy. The kinetics of the reaction were different from those of the constituent lipids of the liposomes. Zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine liposome, which is in the solid-ordered phase, had a better value of reaction rate, suggesting that the reaction rate constants of this reaction in liposome membrane systems could be regulated by the characteristics of the liposome membrane (i.e., the phase state and surface charge). Based on the results obtained, a plausible model of the L-Pro-catalyzed Michael addition reaction was discussed. The obtained results provide us with an easily detectable method to assess the reactivity of L-Pro in biological systems.

scholarly journals Thin Layer Chromatography-A Tool to Investigate Kinetics of Michael Addition Reaction

2018 ◽  
Vol 10 (3) ◽  
pp. 323-329 ◽  
Author(s):  
M. A. B. H. Susan ◽  
G. Ara ◽  
M. M. Islam ◽  
M. M. Rahman ◽  
M. Y. A. Mollah
Keyword(s):  
Ionic Liquids ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Michael Addition ◽  
Binary Systems ◽  
Addition Reaction ◽  
Average Rate ◽  
Michael Addition Reaction ◽  
Layer Chromatography ◽  
Kinetics Of

Thin layer chromatography (TLC), a tool for defining identity, purity, and quantitation of a compound, has also been proved useful for monitoring the progress of a chemical reaction. However, the   technique is yet to be exploited for investigating the kinetics of a reaction systematically. In this work, we used TLC for measuring the time for consumption of a reactant in Michael addition reaction of acetylacetone with 2-cyclohexene-1-one. Average rate of the model reaction was determined using a definite initial concentration of acetylacetone for a series of catalyst systems like NaOH, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), DBU based protic ionic liquids (PILs) 1,8-diazabicyclo[5.4.0]undec-7-ene-8-ium hydroxide ([HDBU]OH) and 1,8-diazabicyclo[5.4.0]undec-7-ene-8-ium acetate ([HDBU]CH3COO), a DBU based aprotic ionic liquid (AIL), 8-hexyl-1,8-diazabicyclo [5.4.0]undec-7-ene-8-ium hydroxide ([C6DBU]OH), and binary systems of the ionic liquids with molecular solvents, such as, water, DBU, and acetic acid. The kinetic data on the performance of the chosen catalysts were interpreted on the basis of the established mechanism of the reaction. Finally, the prospect of the method based on TLC as a suitable technique for kinetic study of chemical reactions has been discussed.

STUDYING THE KINETIC CHARACTERISTICS OF THE EXTRACTION OF ANTHOCYANINS FROM THE SQUEEZE OF KRASNOSTOP ZOLOTOVSKY

2020 ◽  
Author(s):  
M.A. Egyan ◽  
Keyword(s):  
Reaction Rate ◽  
Sugar Content ◽  
Extraction Process ◽  
Efficiency Coefficient ◽  
Kinetic Characteristics ◽  
Reaction Rate Constants ◽  
Solids Content ◽  
Kinetics Of ◽  
Process Speed

The article shows studies characterizing the quality of the squeeze: the mechanical composition of the squeeze is determined, the structural moisture of each component is determined, the sugar content in the formed process of sedimentation of the juice and its acidity are determined refractometrically. The kinetics of anthocyanins extraction was determined in two ways, the solids content in the extract was calculated, and the reaction rate constants of the extraction process and the efficiency coefficient of ultrasonic amplification of the extraction process speed were calculated.

Cupin Variants as Macromolecular Ligand Library for Stereoselective Michael Addition of Nitroalkanes

2019 ◽  
Author(s):  
Nobutaka Fujieda ◽  
Miho Yuasa ◽  
Yosuke Nishikawa ◽  
Genji Kurisu ◽  
Shinobu Itoh ◽  
...  
Keyword(s):  
Michael Addition ◽  
In Silico ◽  
Addition Reaction ◽  
Single Point ◽  
Point Mutations ◽  
Unsaturated Ketone ◽  
Michael Addition Reaction ◽  
Beta Barrel ◽  
Cupin Superfamily ◽  
Single Point Mutations

Cupin superfamily proteins (TM1459) work as a macromolecular ligand framework with a double-stranded beta-barrel structure ligating to a Cu ion through histidine side chains. Variegating the first coordination sphere of TM1459 revealed that H52A and H54A/H58A mutants effectively catalyzed the diastereo- and enantio-selective Michael addition reaction of nitroalkanes to an α,β-unsaturated ketone. Moreover, in silico substrate docking signified C106N and F104W single-point mutations, which inverted the diastereoselectivity of H52A and further improved the stereoselectivity of H54A/H58A, respectively.

Tandem Alkylation/Michael Addition Reaction of Dithiocarbamic Acids with Alkyl γ-Bromocrotonates: Access to Functionalized 1,3-Thiazolidine-2-thiones

Synthesis ◽  
2021 ◽  
Author(s):  
Azim Ziyaei Halimehjani ◽  
Petr Beier ◽  
Maryam Khalili Foumeshi ◽  
Ali Alaei ◽  
Blanka Klepetářová
Keyword(s):  
Amino Acids ◽  
Carbon Disulfide ◽  
Multicomponent Reaction ◽  
Michael Addition ◽  
Addition Reaction ◽  
Primary Amines ◽  
Oxidation Reactions ◽  
Michael Addition Reaction ◽  
Synthetic Utility ◽  
Reaction Proceeds

AbstractThiazolidine-2-thiones were prepared via a novel multicomponent reaction of primary amines (amino acids), carbon disulfide, and γ-bromocrotonates. The reaction proceeds via a domino alkylation/intramolecular Michael addition to provide the corresponding thiazolidine-2-thiones in high to excellent yields. By using diamines in this protocol, bis(thiazolidine-2-thiones) derivatives were synthesized. The synthetic utility of the adducts was demonstrated by hydrolysis, amidation, and oxidation reactions.

Bisphosphine catalyzed sequential [3 + 2] cycloaddition and Michael addition of ynones with benzylidenepyrazolones via dual α′,α′-C(sp3)–H bifunctionalization to construct cyclopentanone-fused spiro-pyrazolones

2018 ◽  
Vol 16 (48) ◽  
pp. 9461-9471 ◽  
Author(s):  
Jiayong Zhang ◽  
Zhiwei Miao
Keyword(s):  
Michael Addition ◽  
Addition Reaction ◽  
Michael Addition Reaction

A sequential [3 + 2] cycloaddition and Michael addition reaction of ynones with benzylidenepyrazolones afforded cyclopentanone-fused spiro-pyrazolones catalyzed by DPPB via dual α′,α′-C(sp3)–H bifunctionalization.

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