- Insights into Thiourea-Based Bifunctional Catalysts for Efficient Conversion of CO2to Cyclic Carbonates
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The bifunctional thiourea catalyst system with both electrophilic and nucleophilic centers has been certified to be effective for fixing CO2 under mild reaction conditions; however, many questions remain, especially concerning the relationship between str
- Li, Zhuo-Qun,Zhang, Yao-Yao,Zheng, Yu-Jia,Li, Bo,Wu, Guang-Peng
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p. 3145 - 3155
(2022/02/14)
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- Novel Multitarget Directed Triazinoindole Derivatives as Anti-Alzheimer Agents
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The multifaceted nature of Alzheimer's disease (AD) demands treatment with multitarget-directed ligands (MTDLs) to confront the key pathological aberrations. A novel series of triazinoindole derivatives were designed and synthesized. In vitro studies revealed that all the compounds showed moderate to good anticholinesterase activity; the most active compound 23e showed an IC50 value of 0.56 ± 0.02 μM for AChE and an IC50 value of 1.17 ± 0.09 μM for BuChE. These derivatives are also endowed with potent antioxidant activity. To understand the plausible binding mode of the compound 23e, molecular docking studies and molecular dynamics simulation studies were performed, and the results indicated significant interactions of 23e within the active sites of AChE as well as BuChE. Compound 23e successfully diminished H2O2-induced oxidative stress in SH-SY5Y cells and displayed excellent neuroprotective activity against H2O2 as well as Aβ-induced toxicity in SH-SY5Y cells in a concentration dependent manner. Furthermore, it did not show any significant toxicity in neuronal SH-SY5Y cells in the cytotoxicity assay. Compound 23e did not show any acute toxicity in rats at doses up to 2000 mg/kg, and it significantly reversed scopolamine-induced memory deficit in mice model. Additionally, compound 23e showed notable in silico ADMET properties. Taken collectively, these findings project compound 23e as a potential balanced MTDL in the evolution process of novel anti-AD drugs.
- Patel, Dushyant V.,Patel, Nirav R.,Kanhed, Ashish M.,Patel, Sagar P.,Sinha, Anshuman,Kansara, Deep D.,Mecwan, Annie R.,Patel, Sarvangee B.,Upadhyay, Pragnesh N.,Patel, Kishan B.,Shah, Dharti B.,Prajapati, Navnit K.,Murumkar, Prashant R.,Patel, Kirti V.,Yadav, Mange Ram
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p. 3635 - 3661
(2019/08/20)
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- Synthesis and structures of zwitterionic polymers to induce electrostatic interaction with PDMS surface treated by air-plasma
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Various zwitterionic polymers, sulfobetaine and phosphoryl choline derivatives were synthesized in order to investigate zwitterionic polymer structures toward surface modification of PDMS, where the adsorption of zwitterionic polymers on polydimethylsiloxane surface treated with air-plasma was induced by the electrostatic interaction,. The electrostatic interaction was evaluated with hydrophilicity. The results suggested that a sulfobetaine polymer with higher molecular weight, lower molecular weight distribution, and shorter alkyl chain afforded high electrostatic interaction. A sulfobetaine polymer bearing phenylazide group showed similar electrostatic interaction with the PDMS surface, and it is a promising material for surface modification ofpolydimethylsiloxane.
- Tanaka, Mutsuo,Hirata, Yoshiki,Sawaguchi, Takahiro,Kurosawa, Shigeru
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p. 330 - 343
(2018/06/29)
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- Continuous chemoselective methylation of functionalized amines and diols with supercritical methanol over solid acid and acid-base bifunctional catalysts
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The selective N-methylation of bifunctionalized amines with supercritical methanol (scCH3OH) promoted by the conventional solid acids (H-mordenite, β-zeolite, amorphous silica-alumina) and acid-base bifunctional catalysts (Cs-P-Si mixed oxide and γ-alumina) was investigated in a continuous-flow, fixed-bed reactor. The use of scCH 3OH in the reaction of 2-aminoethanol with methanol (amine/CH 3OH = 1/10.8) over the solid catalysts led to a significant improvement in the chemoselectivity of the N-methylation. Among the catalysts examined, the Cs-P-Si mixed oxide provided the most efficient catalyst performance in terms of selectivity and reactivity at 300 °C and 8.2 MPa; the N-methylation selectivity in the products reaching up to 94% at 86% conversion. The present selective methylation was successfully applied to the synthesis of N-methylated amino alcohols and diamines as well as O-methylated ethylene glycol. Noticeably, ethoxyethylamine was less reactive, suggesting that the hydroxy group of the amino alcohols is a crucial structural factor in determining high reactivity and selectivity, possibly because of the tethering effect of another terminus, a hydroxo group, to the catalyst surface. The magic-angle-spinning NMR spectroscopy and X-ray diffraction analysis of the Cs-P-Si mixed oxide catalyst revealed that the acidic and basic sites originate from P2O5/SiO2 and Cs/SiO2, respectively, and the weak acid-base paired sites are attributed to three kinds of cesium phosphates on SiO2. The weak acid-base sites on the catalyst surface might be responsible for the selective dehydrative methylation.
- Oku, Tomoharu,Arita, Yoshitaka,Tsuneki, Hideaki,Ikariya, Takao
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p. 7368 - 7377
(2007/10/03)
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- Long-range anisotropic effects of long chain amides
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In 1H-NMR spectra of amids with long-chain aliphatic N-substituents one observes - despite of the free mobility of the aliphatic chain - splitting of the signals of the terminal methyl groups which is caused by the hindered rotation of the amide bond. - Keywords: Amides; Hindered rotation; 1H-NMR
- Budzikiewicz, Herbert,Vieth, Peter-Eric,Krueger, Uwe
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p. 825 - 840
(2007/10/02)
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