626-15-3Relevant articles and documents
A new fluorescent probe based on quinoline for detection of Al3+ and Fe3+ with "off-on-off" response in aqueous solution
Dai, Yanpeng,Liu, Xiaoyan,Wang, Peng,Fu, Jiaxin,Yao, Kun,Xu, Kuoxi
, p. 99933 - 99939 (2016)
A new quinoline-based fluorescent probe 1 has been designed and synthesized. Fluorescence emission spectra of the probe showed red-shift and obvious enhancement of fluorescent intensity upon the addition of Al3+ (turn-on). 1-Al3+ showed high selectivity for Fe3+ over other metal ions, and eliminated the interference of Al3+ during Fe3+ detection (turn-off). It showed highly selective relay recognition of Al3+ and Fe3+via a fluorescence "off-on-off" mechanism. Fluorescence spectra indicated that the response of 1-Al3+ to Fe3+ was caused by central metal displacement. The detection limits for the analysis of Al3+ and 1-Al3+-Fe3+ ions were calculated to be 2.20 × 10-6 M and 1.96 × 10-5 M, respectively. Living HeLa cell imaging studies revealed that the probe was cell-permeable and it could be used to detect intracellular Al3+ and Fe3+ ions.
Exploiting Peptidomimetics to Synthesize Compounds That Activate Ryanodine Receptor Calcium Release Channels
Robinson, Ken,Easton, Christopher J.,Dulhunty, Angela F.,Casarotto, Marco G.
, p. 1957 - 1971 (2018/09/11)
Ryanodine receptor (RyR) Ca2+-release channels are essential for contraction in skeletal and cardiac muscle and are prime targets for modification of contraction in disorders that affect either the skeletal or heart musculature. We designed and synthesized a number of compounds with structures based on a naturally occurring peptide (A peptides) that modifies the activity of RyRs. In total, 34 compounds belonging to eight different classes were prepared. The compounds were screened for their ability to enhance Ca2+ release from isolated cardiac sarcoplasmic reticulum (SR) vesicles, with 25 displaying enhanced Ca2+ release. Competition studies with the parent peptides indicated that the synthetic compounds act at a competing site. The activity of the most effective of the compounds, BIT 180, was further explored using Ca2+ release from skeletal SR vesicles and contraction in intact skeletal muscle fibers. The compounds did not alter tension in intact fibers, indicating that (as expected) they are not membrane permeable, but importantly, that they are not toxic to the intact cells. Proof in principal that the compounds would be effective in intact muscle fibers if rendered membrane permeable was obtained with a structurally related membrane-permeable scorpion toxin (imperatoxin A), which was found to enhance contraction.
Study on the synthesis of novel fluorescent macrocyclic sensors and their sensitive properties for Cu2+ and Fe3+ in aqueous solution
Dai, Yanpeng,Xu, Kuoxi,Wang, Chaoyu,Liu, Xiaoyan,Wang, Peng
, p. 315 - 322 (2017/02/15)
In this work, we synthesised and characterised three novel fluorescence macrocyclic sensors containing optically active dansyl groups. The studies for the interaction of the synthesised compounds with various mental ions (Li+, Na+, K+, Ag+, Mg2+, Ca2+, Ba2+, Pb2+, Zn2+, Co2+, Cd2+, Hg2+, Ni2+, Cu2+, Mn2+, Cr3+, Al3+, Fe3+) were performed by fluorescence titration, Job’s plot, ESI-MS and DFT calculations. The results showed that the sensors 1a–1c displayed selective recognition for Cu2+ and Fe3+ ions and formed stoichiometry 1:1 complex through PET mechanism in DMSO/H2O solution (1:1, v/v, pH 7.4 of HEPES). The binding constant (K) and detection limit were calculated.
Pinpoint-fluorinated polycyclic aromatic hydrocarbons (F-PAHs): Syntheses of difluorinated subfamily and their properties
Fuchibe, Kohei,Shigeno, Kento,Zhao, Nan,Aihara, Hiromichi,Akisaka, Rikuo,Morikawa, Toshiyuki,Fujita, Takeshi,Yamakawa, Kie,Shimada, Toshihiro,Ichikawa, Junji
, p. 173 - 184 (2017/10/23)
Difluorinated polycyclic aromatic hydrocarbons (PAHs) containing three to five benzene rings were systematically synthesized by the Pd(II)-catalyzed Friedel–Crafts-type cyclization of 1,1,2-trifluoro- and 1,1-difluoro-1-alkenes and the In(III)-catalyzed tandem cyclization of bis(1,1-difluoroallene)s. Using an array of the difluorinated PAHs that were obtained and previously reported monofluorinated PAHs, the physical properties of the pinpoint-fluorinated PAHs were investigated. (i) The 19F NMR signals of the bay-region fluorine atoms were shifted downfield by ca. 8–14 ppm for vic-difluorinated PAHs and ca. 11–19 ppm for non-vic-difluorinated and monofluorinated PAHs. (ii) The introduction of fluorine into PAH molecules increased their solubilities in organic solvents, which was best exemplified by the high solubilities of 6,7-difluoropicene (5.4 wt%) and 6-fluoropicene (5.3 wt%) in THF. (iii) The HOMO–LUMO energy gaps of the pinpoint-fluorinated PAHs were smaller than that of the corresponding fluorine-free PAH (i.e., picene) by 0.02–0.26 eV, and the HOMO and LUMO energy levels were lowered by 0.10–0.22 eV and 0.12–0.41 eV, respectively.
Improved Halogenation of Methyl Aromatics and Methyl Heteroaromatics: Unexpected Reactivity of Tetrahalogeno-diphenylglycolurils
Moretti, Florian,Poisson, Guillaume,Marsura, Alain
, p. 173 - 183 (2016/05/19)
1,3,4,6-Tetrachloro (TCDGU) and 1,3,4,6-tetrabromo-3α,6α-diphenylglycolurils smooth halogen oxidizers have been exploited in a new direction as reagents for free radical substitution toward some N-halosuccinimide nonreactive bis-heterocycles. An unexpected selectivity and reactivity were observed with methyl benzenes, methyl heterocycles, and methyl-bis-heterocycles of interest. A chemometric study has been performed to optimize five independent factors of the chlorination reaction with TCDGU. The predictive model was established either for the halogenation conversion and the ratio of monochlorination.
Synthesis and thermal stability of new polynitrostilbenes
Wei, Jianping,Li, Fangmei,Xu, Junhui,Peng, Xinhua
, p. 919 - 925 (2015/06/25)
New polynitrostilbenes were directly synthesised by the Knoevenagel condensation of aromatic aldehydes with nitrotoluenes. The differential scanning calorimetry results demonstrated that the introduction of an amino group and C≤C double bonds could improve the thermal stability.
Distinct structures of inorganic-organic supramolecular assemblies based on discrete metallocyclic complexes incorporating flexible imidazole ligands: Syntheses, crystal structures and properties
Yang, Li,Chang, Guanjun,Luo, Liang,Ding, Feng,You, Jingsong
, p. 307 - 314 (2013/10/22)
Three new interesting discrete dinuclear metallocyclic complexes, namely, {[Pd2(1)4](NO3)4· 2DMSO· 2H2O}n (4), [Pd2(2) 2Br4]n (5), and {[Pd2(3) 2Cl4]·4DMSO}n (6) have been successfully synthesized by the reaction of flexible exo-bidentate imidazole-containing ligands 1, 3-bis(imidazol-1-ylmethyl)benzene (1), 1, 3-bis(imidazol-1-ylmethyl)- 5-methylbenzene (2), and 2, 6-bis(imidazol-1-ylmethyl)-4-tert-butyl-phenol (3) with corresponding palladium salts. All these complexes were characterized by NMR spectroscopy in combination with elemental analysis, powder X-ray diffraction (PXRD), single-crystal X-ray diffraction, and thermal gravimetric analysis (TGA), respectively. Though all three complexes involve the similar supramolecular building blocks [2+2] metallocyclic units, under the inducement effect of the organic ligands, compounds 4-6 exhibit delicate geometric diversification of the resulting high-dimensional inorganic-organic supramolecular assemblies (e.g., [4+2] lantern-like cage structure, 1D channel, and 2D undulating framework, respectively). Furthermore, these results demonstrate that the secondary interactions such as intermolecular π ··· π stacking interactions and hydrogen bonds could play important roles in the aspect of linking low-dimensional entities into high-dimensional supramolecular frameworks.
Synthesis and intramolecular hydrogen bonding of syn -9-hydroxy-18- substituted [3.3]metacyclophanes
Tazoe, Kazuya,Feng, Xing,Sharma, Bigyan,Miyamoto, Shinpei,Yamato, Takehiko
body text, p. 222 - 229 (2012/03/07)
Various anti-9-methoxy[3.3]metacyclophane-2,11-diones are exclusively obtained by the coupling reaction of the corresponding 1,3-bis(bromomethyl) benzenes and 2,6-bis[2-isocyano-2-(tolylsulfonyl)ethyl]-4-tert-butylanisole in dimethylformamide (DMF) with an excess of sodium hydride, from which the corresponding syn-[3.3]metacyclophanes (MCPs) are synthesized via anti/syn-isomerization during the Wolff-Kishner reduction. Demethylation of syn-9-methoxy[3.3]MCPs with BBr3 afforded the corresponding syn-9-hydroxy[3.3]MCPs in good yields. The existence of the strong intramolecular hydrogen bonding between the 9-hydroxy group and the 18-substituents, such as F, OH, and OMe groups at the opposing aromatic rings, are observed in solution and in the solid state. A distinct low-field shift of the phenolic OH proton was observed in the 1H NMR spectrum compared with that of the 18-unsubstituted analog. Furthermore, O-H...F through-space coupling was observed.
Generation of (nonafluoro-tert-butoxy)methyl ponytails for enhanced fluorous partition of aromatics and heterocycles
Zhao, Xi,Ng, Wing Yan,Lau, Kai-Chung,Collis, Alana E. C.,Horvath, Istvan T.
experimental part, p. 3909 - 3914 (2012/06/30)
The reaction of sodium perfluoro-tert-butoxide with benzylic carbon-bromide bond(s) leads to the formation of (nonafluoro-tert-butoxy)methyl ponytail(s), which can enhance the fluorous solubility and partition of aromatics and heterocycles.
Homodimeric bis-quaternary heterocyclic ammonium salts as potent acetyl- and butyrylcholinesterase inhibitors: A systematic investigation of the influence of linker and cationic heads over affinity and selectivity
Conejo-García, Ana,Pisani, Leonardo,Del Carmen Nú?ez, Maria,Catto, Marco,Nicolotti, Orazio,Leonetti, Francesco,Campos, Joaquín M.,Gallo, Miguel A.,Espinosa, Antonio,Carotti, Angelo
body text, p. 2627 - 2645 (2011/06/21)
A molecular library of quaternary ammonium salts (QASs), mainly composed of symmetrical bis-quaternary heterocyclic bromides exhibiting choline kinase (ChoK) inhibitory activity, were evaluated for their ability to inhibit acetyl- and butyrylcholinesterase (AChE and BChE, respectively). The molecular framework of QASs consisted of two positively charged heteroaromatic (pyridinium or quinolinium) or sterically hindered aliphatic (quinuclidinium) nitrogen rings kept at an appropriate distance by lipophilic rigid or semirigid linkers. Many homodimeric QASs showed AChE and BChE inhibitory potency in the nanomolar range along with a low enzymatic selectivity. Computational studies on AChE, BChE, and ChoK allowed identification of the key molecular determinants for high affinity and selectivity over either one of the three enzymes and guided the design of a hybrid bis-QAS (56) exhibiting the highest AChE affinity (IC50 = 15 nM) and selectivity over BChE and ChoK (SI = 50 and 562, respectively) and a promising pharmacological potential in myasthenia gravis and neuromuscular blockade.
