123-98-8Relevant academic research and scientific papers
Temperatures and enthalpies of solid-solid and melting transitions of the odd-numbered n-alkanes C21, C23, C25, C27, and C29
Chevallier, Virginie,Bouroukba, Mohammed,Petitjean, Dominique,Barth, Danielle,Dupuis, Paul,Dirand, Michel
, p. 1114 - 1122 (2001)
Very high purity samples of normal pentacosane and heptacosane are made by synthesis: the procedures for the C25 and C27 synthesis and the original conditions of their purification, particularly using the extraction by supercritical carbon dioxide, are described. Measurements of temperatures and enthalpies of the solid-solid transitions and of the melting transition were carried out by differential scanning calorimetry on the C25 and C27 synthetic samples and the odd-numbered homologous n-alkanes (from C21 to C29). The results show the importance of the effect of the impurities, particularly for the δ and γ crystal-crystal transition temperatures of C25 and C27. Several current data of the literature are also shown concerning the temperatures and the enthalpies of solid-solid and melting transitions of these five n-alkanes.
Aziridine-2-carboxylic acid derivatives and its open-ring isomers as a novel PDIA1 inhibitors
Leite, Irena,Andrianov, Victor,Zelencova-Gopejenko, Diana,Loza, Einars,Kazhoka-Lapsa, Iveta,Domracheva, Ilona,Stoyak, Marta,Chlopicki, Stefan,Kalvins, Ivars
, p. 1086 - 1106 (2022/01/12)
[Figure not available: see fulltext.] Acyl derivatives of aziridine-2-carboxylic acid have been synthesized and tested as PDIA1 inhibitors. Calculations of charge value and distribution in aziridine ring system and some alkylating agents were performed. For the first time was found that acyl derivatives of aziridine-2-carboxylic acid are weak to moderately active PDIA1 inhibitors.
Synthesis of 1-Palmitoyl-2-((E)-9- and (E)-10-nitrooleoyl)- sn -glycero-3-phosphatidylcholines
Dietz, Ulrich,Frank, Andrea,Lehr, Alexander,Münch, Winfried,Nubbemeyer, Udo
supporting information, p. 3295 - 3304 (2019/08/28)
Extensive investigation of nitrated phospholipids in connection with various biologically important processes requires reliable access to suitable material. A selective chemical synthesis introducing a defined nitrofatty acid at the sn -2 position of a 2-lyso sn -glycero-3-phosphatidylcholine was developed. Given that the nitroalkene moiety of both reactant nitrofatty acid derivative and the product esters is characterised by particular sensitivity to nucleophile addition and, depending on the intermediate, subsequent olefin isomerisation and retro-Henry-type reaction, a reliable two-step ester formation was introduced. The activation of the nitrofatty acid succeeded after reaction with trichlorobenzoyl chloride, and the mixed anhydride could be isolated via extractive work-up. Subsequent reaction with 1-palmitoyl-2-lyso- sn -glycero-3-phosphatidylcholine enabled the sn -2 esterification to be achieved with high yield by using a minimum of reagents, avoiding the formation of side products and facilitating final isolation and purification.
Small-Molecule Activators of Glucose-6-phosphate Dehydrogenase (G6PD) Bridging the Dimer Interface
Raub, Andrew G.,Hwang, Sunhee,Horikoshi, Naoki,Cunningham, Anna D.,Rahighi, Simin,Wakatsuki, Soichi,Mochly-Rosen, Daria
supporting information, p. 1321 - 1324 (2019/07/04)
We recently identified AG1, a small-molecule activator that functions by promoting oligomerization of glucose-6-phosphate dehydrogenase (G6PD) to the catalytically competent forms. Biochemical experiments indicate that the activation of G6PD by the original hit molecule (AG1) is noncovalent and that one C2-symmetric region of the G6PD homodimer is important for ligand function. Consequently, the disulfide in AG1 is not required for activation of G6PD, and a number of analogues were prepared without this reactive moiety. Our study supports a mechanism of action whereby AG1 bridges the dimer interface at the structural nicotinamide adenine dinucleotide phosphate (NADP+) binding sites of two interacting G6PD monomers. Small molecules that promote G6PD oligomerization have the potential to provide a first-in-class treatment for G6PD deficiency. This general strategy could be applied to other enzyme deficiencies in which control of oligomerization can enhance enzymatic activity and/or stability.
Azelanitrile preparation method
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Paragraph 0068-0071, (2019/10/01)
The invention relates to an azelanitrile preparation method, which comprises: (1) dissolving glutaraldehyde in a solvent, adding a condensation catalyst and an optional cocatalyst, adding cyanoaceticacid in batches to maintain the temperature of the reaction solution of not more than 40 DEG C, and carrying out a condensation reaction, wherein a molar ratio of the glutaraldehyde to the cyanoaceticacid is 1:2; and (2) further adding a palladium carbon catalyst (Pd/C) to the condensation reaction liquid obtained in the step (1), introducing hydrogen gas, maintaining the pressure, heating, and carrying out a decarboxylation and hydrogenation reaction to obtain azelanitrile, wherein the hydrogen pressure is 3.0-4.0 MPa. According to the present invention, the method can perform the reaction by using the one-step method so as to eliminate the separation and purification process of the intermediate product, such that the reaction process is simple, and the cost is low.
Thermotropic liquid crystalline polyesters derived from 2-chloro hydroquinone
Manurkar, Nagesh,More, Sayaji,Mulani, Khudbudin,Ganjave, Nitin,Chavan, Nayaku
, p. 1461 - 1468 (2017/09/27)
Abstract: Synthesis of thermotropic liquid crystalline polyesters derived from bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene (BHBOCB) and aliphatic dicarboxylic acid chlorides by interfacial polycondensation methodology is presented. Synthesised polyesters consist of bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene as a mesogen and aliphatic diacid chloride as flexible spacer. The length of oligomethylene units in the polymer was varied from the trimethylene to the dodecamethylene groups. Synthesized polyesters were characterized by differential scanning calorimetry and optical microscopy. The transition temperatures and thermodynamic properties were studied for all these polymers. These polyesters exhibited thermotropic liquid crystalline behavior and showed nematic texture except decamethylene spacer. Decamethylene spacer based polyester showed marble texture of smectic C. Mesophase stability of these polyesters was higher than 123 °C (except first heating cycle of PE-1). Graphical Abstract:: SYNOPSIS The present study deals with the synthesis of thermotropic liquid crystalline polyesters derived from bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene (BHBOCB) and aliphatic dicarboxylic acid chlorides by interfacial polycondensation methodology. [Figure not available: see fulltext.].
Towards New Oligomesogenic Phosphonic Acids as Stabilizers of Nanoparticles Colloids in Nematic Liquid Crystals
Prodanov, Maksym F.,Diakov, Maksym Y.,Vlasenko, Ganna S.,Vashchenko, Valerii V.
supporting information, p. 1905 - 1910 (2015/08/06)
Several synthetic strategies for the construction of linear and branched oligomesogenic phosphonic acids are examined, which differ in the method of building the key bimesogen unit. An efficient synthetic approach to the most promising compounds employs regioselective Kumada cross-coupling between [11-(4′-pentylbiphenyl-4-yl)undecyl]magnesium bromide and 4-(11-bromoundecyl)-4′-iodobiphenyl as the key step. Preliminary studies on the ability of the new ligands to stabilize nanoparticles colloids in nematic liquid crystals are undertaken for the example of quantum dots.
Synthesis and binding profile of haloperidol-based bivalent ligands targeting dopamine D2-like receptors
Salama, Ismail,L?ber, Stefan,Hübner, Harald,Gmeiner, Peter
supporting information, p. 3753 - 3756 (2014/09/16)
Homodimers of dopamine D2-like receptors are suggested to be of particular importance in the pathophysiology of schizophrenia and, thus, serve as promising targets for the discovery of atypical antipsychotics. This study describes the development of a series of novel bivalent molecules with a pharmacophore derived from the dopamine receptor antagonist haloperidol. These dimers were investigated in comparison to their monomeric analogues for their D2long, D2short, D3, and D4 receptor binding and the ability to bridge two neighboring receptor protomers. Radioligand binding studies provided diagnostic insights when Hill slopes close to two for the bivalent ligand 13 incorporating 22 spacer atoms and a comparative analysis with monovalent control ligands indicated a bivalent binding mode with a simultaneous occupancy of two neighboring binding sites.
Physical gels made of liquid crystalline B4 phase
Zep, Anna,Salamonczyk, Miroslaw,Vaupotic, Natasa,Pociecha, Damian,Gorecka, Ewa
supporting information, p. 3119 - 3121 (2013/06/27)
The achiral liquid crystalline materials showing two B4 (HN) phases have been found to exhibit strong gelation ability for various organic solvents with reversible sol-gel phase transition. The gel is formed by helical tubules, which build entangled 3D network, encapsulating the solvent. The equilibrium of left- and right-handed tubules is preserved in the gel, even if the chiral solvent is used.
Synthesis, thermal, and photocrosslinking studies of thermotropic liquid crystalline poly(benzylidene-ether)esters containing α,β-unsaturated ketone moiety in the main chain
Muthusamy, Athianna,Balaji, Krishnasamy,Murugavel, Salem Chandrasekaran
, p. 1707 - 1715 (2013/04/24)
A series of poly(benzylidene-ether)esters containing a photoreactive benzylidene chromophore in the main chain were synthesized from 2,6-bis(4-hydroxy-3-methoxybenzylidene)cyclohexanone (BHMBCH) with various aliphatic and aromatic diacid chlorides by an interfacial polycondensation technique. The intrinsic viscosity of the synthesized homo and copolymers determined by Ubbelohde viscometer was found to be 0.12 to 0.17 dL/g. The molecular structure of the monomer and polymers was confirmed by FT-IR, 1H NMR, and 13C NMR spectral analyses. These polymers were studied for their thermal stability and photochemical properties. Thermal properties were evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). It was found that the polymers were stable up to 280 °C and start degrading thereafter. Increase in acid methylene spacer length decreased the thermal stability. The self-extinguishing property of the synthesized polymers was studied by calculating the limiting oxygen index (LOI) value using a Van Krevelen's equation. The influence of the length of methylene spacer on phase transition was investigated using DSC and odd-even effect has been observed. Hot-stage optical polarizing microscopic (HOPM) study showed that most of the polymers exhibited birefringence and opalescence properties. The photolysis of liquid crystalline poly(benzylidene-ether)esters revealed that α,β-unsaturated ketone moiety in the main chain dimerises through 2π + 2π cycloaddition reaction to form a cyclobutane derivative and leads to crosslinking.
