Asian Journal of Organic Chemistry
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2018
·Vol. 7
·期 12
·2527-2533
·
IF 2.496
Wei-Ze Li,Zhong-Xia Wang
Graphical Reaction of quinoline N -oxides and pyridine N -oxides with arylzinc reagents under transition-metal-free conditions was studied. The reaction was carried out in toluene (for quinoline N -oxides) or THF (for pyridine N -oxides) at 100 °C and required 2 equiv. of arylzinc loadings and the presence of 2.5 equiv. of TFAA, affording 2-arylquinolines and 2-arylpyridines, respectively, in 24% to 95% yields. Reaction of quinoline N -oxides and pyridine N -oxides with arylzinc reagents under transition-metal-free conditions was studied. The reaction was carried out in toluene (for quinoline N -oxides) or THF (for pyridine N -oxides) at 100 °C and required 2 equiv. of arylzinc loadings and the presence of 2.5 equiv. of TFAA, affording 2-arylquinolines and 2-arylpyridines, respectively, in 24% to 95% yields. Functional groups OMe, F, Cl, Br, CF 3 , C(O)NH 2 , COOR and NO 2 were tolerated. Mechanistic studies showed that the reaction of quinoline N -oxides proceeded via a 2-arylquinolin-1(2 H )-olate intermediate, and the reaction of pyridine N -oxides via a 5-arylpenta-2,4-dienal oxime intermediate.
研究领域:
有机化学
·
合成化学
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Weiting Jiao,Lei Zhu,Tingting Shen,Luyao Wang,Qing X. Li,Chen Wang,Xiangwei Wu,Hongping Chen,Rimao Hua
Pyrrolizidine alkaloids (PAs) and their N -oxides (PANOs) are novel contaminants in tea. However, the source of PA/PANO contamination in tea remains unclear. In this study, 15 PAs/PANOs were extracted from plant samples (tea, fresh tea leaves, and weeds) with 0.1 M sulfuric acid and from soil with 0.1 M sulfuric acid methanol after adjusting soil acidity with 0.1 M trisodium citrate. Satisfactory recoveries of PAs/PANOs from four different matrices at 0.02, 0.1, and 0.5 mg kg −1 was 72%–114% with relative standard deviations (RSD) of 0.03%–16%. Seven out of 15 PAs/PANOs were detected in tea purchased from the local market ranging from undetected to 96.2 μg kg −1 . Thirteen, three, and four PAs/PANOs were detected in weeds, fresh tea leaves, and soil, respectively. Based on the types of PAs/PANOs detected in the three matrices, it was preliminarily speculated that PAs/PANOs in tea originated from weeds in the tea garden.
研究领域:
食品科学
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植物学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2021
·
IF 6.165
Jianhui Jia,Jianbo Chen,Huan Ding,Xianggui Xue,Shichun Li,Jichun Huang,Yu Liu
N- oxide based explosives display better explosive performances than traditional explosives, because of the introduction of N- oxide group with strong hydrogen bonding (H-bonding). However, the strong H-bonding results in poor dissolution of N- oxide based explosives, and thus poses a significant challenge for their potential applications. Deep eutectic solvents (DESs), a new generation of green solvents, display promising dissolution toward strong H-bonding materials in recent years. In this study, 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) was used as a prototype of N- oxide based explosives to study the dissolution in DESs. The dissolution conditions for LLM-105 were optimized by using different types of DESs. The DES-3 - 2 based on choline chloride and urea displayed higher dissolving capacity with 0.52 g/100 g at 80 °C, which was determined by traditionally gravimetric method. Further, the dissolution process of LLM-105 in DES-3 - 2 under different temperatures was investigated by comprehensive analysis including ultra-high-performance liquid chromatography, high-resolution mass spectrum and theoretical calculations. The dissolution of LLM-105 under ≤80 °C was demonstrated to be real dissolution referring to the formation of Zundel-type complex and Meisenheimer complex between DES-3 - 2 and LLM-105. Abnormally high solubility of LLM-105 at >80 °C was attributed to the self-collapse of its H-bonding network by losing a nitro group and an oxygen of N- oxide group.
研究领域:
化学
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材料科学
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Yang Liu,Guiliang Li,Qiu Han,Haibo Lin,Qiang Li,Gang Deng,Fu Liu
Dialysis membranes capable of preventing coagulation and inflammation and achieving high toxin clearances are highly desired for clinical hemodialysis. Here, we constructed an electro-neutral and hydrophilic surface on Polysulfone (PSf) membrane, which both improved the hemocompatibility and toxin clearance. The membrane surface was modified with trimethylamine N-oxide (TMAO) through Michael addition reaction and subsequent crosslinking with glycidyl ether oxypropyl trimethoxysilane (KH560). Saltwater fish inspired zwitterionic monomer TMAO without spacers between positive and negative headgroups is thought to generate a hydrated and net-charged layer that prevents non-specific plasma proteins and platelets adsorption and activation. Coagulation time, serine protease Factor XIIa, bradykinin (BK), kallikrein (KLK) and anaphylatoxins (C3, C5 and SC5b-9) were examined to explore blood compatibility. All results showed that the highly hydrated and electro-neutral surface could efficiently alleviate the activation of the coagulation cascade, kallikrein-kinin system (KKS) and complement system simultaneously. Furthermore, the modified PSf membrane is favorable to toxins clearance (e.g., urea, creatine, lysozyme and vitamin B12) during simulated dialysis process. It is manifested that the TMAO based surface modification is feasible for improving the hemocompatibility and toxin clearance of dialysis membranes.
研究领域:
生物医学工程
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材料科学
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血液学
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产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2023
·
IF 3
Yutao Lou,Zhiyong Sun,Yitao Chai,Hui Qin,Qing Hu,Yujia Liu,Xiaowei Zheng,Ying Hu,Meihua Bao,Jinping Gu,Yiwen Zhang
Donafenib and sorafenib are small molecule chemotherapy drugs for the management of hepatocellular carcinoma, with donafenib being a deuterated derivative of sorafenib. To date, a high liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method that quantify donafenib, sorafenib, and their main metabolites has not yet been developed. The objective of this study was to establish a HPLC-MS/MS method for the simultaneous detection of donafenib, donafenib-N-oxide, sorafenib, and sorafenib-N-oxide and for the pharmacokinetic studies in rat. The extraction of all analytes was achieved by simple protein precipitation utilizing acetonitrile. The Waters XBridge C 18 column (2.1 × 100 mm, 3.5 µm) was selected, and the analytes could be efficiently separated and quantitated during a 2.8 min gradient elution procedure. The method was linear within the predefined quantification ranges and provided acceptable precision (%CV < 9.4%), reproducible extraction recovery (99.4%–111.5%), and low matrix effect (88.1%–98.6%). The hemolysis effect did not interfere with the quantification of all analytes, and similar results were obtained by changing the anticoagulant K 2 -EDTA to heparin or sodium citrate. Plasma pharmacokinetics revealed that the values of t 1/2 , C max , and AUC 0-t of donafenib were 1.4-, 6.2-, and 3.1-fold higher than those of sorafenib, respectively. In conclusion, the proposed bioassay was successfully applied to pharmacokinetic studies in rat after administration of donafenib and sorafenib. Our work not only improves the bioanalytical method for determining the plasma concentrations of donafenib, sorafenib, and their N-oxide metabolites, but also provides a scientific reference for clinical pharmacokinetic studies.
研究领域:
药物化学
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临床药理学
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分析化学
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产品关联
DOI
PubMed
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2025
·
IF 6.1
Xingxing Liu,Kangle Jia,Junhua Ning,Qiuping Su,Huanling Li,Wu Wen,Xiaoshan Zhen,Jinlan Xin,Yuanqing Lin,Longfei Yu
Oil fouling and low flux present significant challenges for membrane application in oil-water separation. Enhancing the hydrophilicity of intrinsically hydrophobic membranes is crucial for improving their antifouling performance through a simple modification. In this study, inspired by the natural mechanisms of saltwater fish and mussels, an antifouling zwitterionic surface was fabricated via co-assembly of a novel N-oxide zwitterionic copolymer (PTODA) and dopamine (DA). The zwitterionic groups in PTODA with the direct link between opposite charges (N + -O − ) create a strong hydration barrier by interacting with water molecules, effectively resisting oil adhesion and enhancing oil-water emulsion permeability. Moreover, the self-polymerization and interaction of catechol groups within DA and PTODA during the co-deposition progress could facilitate the stable anchoring of the zwitterionic copolymer onto the membrane. As expected, the modified membrane thus exhibits excellent hydrophilicity, underwater superoleophobicity, and oil-fouling resistance. Upon optimizing the zwitterionic copolymer composition, the as-fabricated PVDF-PTODA121 exhibited high efficiency of oil-water separation performance, achieving a water permeability of 10,357 L m −2 h −1 bar −1 , a mineral oil-water emulsion flux of 5634 L m −2 h −1 bar −1 , a recovery rate of 90.8 % and a rejection of 99.6 %. Meanwhile, the PVDF-PTODA121 membrane maintained high fouling-resistance and excellent stability under challenging environmental conditions and multiple cycles. Hence, this study presents a novel strategy for fabricating superwetting antifouling membranes through dual-biomimetic methods for achieving efficient separation of oil-water emulsion.
研究领域:
材料科学
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环境工程
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表面化学
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产品关联
DOI
高影响因子
CELLULOSE
·
2022
·Vol. 29
·期 3
·1473-1485
·
IF 6.123
Xia Yuanyuan,Li Xinping,Yuan Yue,Zhuang Jingshun,Wang Wenliang
The preparation of cellulose beads has attracted much attention in the application of advanced green materials. Herein, the uniform and controllable cellulose beads were prepared by first dissolving the pulp into N-methylmorpholine N-oxide (NMMO), and then regenerated in various coagulation baths (water, alcohol, acid, NMMO, etc.). Results showed that the crystalline structure of regenerated cellulose changed from cellulose I to cellulose II. Besides, the cellulose beads regenerated in Methanol (MT-cellulose bead) had the highest porosity (90.51%) and crystallinity (62.59%). Laser confocal microscopy was employed to reveal the coagulation mechanism of cellulose beads, and the solidification process was carried out from the inside to the outside. This is a green and facile method for preparing cellulose beads with different structures and properties that can be widely used in absorbent materials, energy storage materials, and protein chromatography. Graphical abstract
研究领域:
材料科学
·
绿色化学
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产品关联
DOI
高影响因子
MACROMOLECULES
·
2023
·
IF 5.5
Jinkang Dou,Minghui Xu,Bojun Tan,Hongchang Mo,Xianming Lu,Bozhou Wang,Ning Liu
Nitrile N-oxide-based click ligation is a very promising technique for polymer crosslinking due to the unique advantages of catalyst-free and byproduct-free reactions. For this technique, nitrile N-oxides that are sufficiently stable at room temperature and have high reactivity under mild conditions are very desirable. Usually, neighboring bulky substituents are introduced to enhance the stability of nitrile N-oxides, which however bring the reactivity down due to the high steric hindrance. Herein, methyl groups, small-sized substituents, were introduced into the o,o′-positions of phenyl nitrile N-oxides to enable high stability and high reactivity. Thus, several novel aromatic nitrile N-oxides were synthesized. Among them, ditopic aromatic nitrile N-oxides were prepared through three simple steps including etherification, oximation, and oxidative dehydrogenation, whereas stable tritopic aromatic nitrile N-oxides were synthesized by directly introducing the nitrile N-oxide functionality into the corresponding trifunctional compounds to avoid undesirable side reactions. These nitrile N-oxides as ligation reagents exhibited very high reactivity, and efficient catalyst-free crosslinking of natural rubber was achieved at room temperature to give elastomers with good mechanical properties, revealing the potential of such nitrile N-oxides as useful crosslinkers for unsaturated bond-containing polymers. This work provides reliable synthesis of stable ditopic/tritopic aromatic nitrile N-oxides, broadening the application of the nitrile N-oxide-based click ligation technique toward catalyst-free and byproduct-free polymer crosslinking.
研究领域:
材料科学
·
有机化学
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产品关联
DOI
高影响因子
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
·
2025
·
IF 2.2
Xiaoyun Yang,Yi Wang,Yujin Feng,Feng Wang,Lijuan Gao,Yueheng Wang
Myocardial infarction is often accompanied by symptoms of myocardial fibrosis, causing myocardial systolic and diastolic dysfunction. High levels of TMAO are considered to be strongly connected to cardiovascular diseases occurrence. The objective of this investigation was to determine whether formal TMAO affects the development of cardiac muscle fibers. The left anterior descending (LAD) coronary artery was ligated to construct myocardial infarction mouse model, while the control group mouse was only operated vessel separation. According to whether or not TMAO intervention is given, mice were divided into control, TMAO, myocardial infarction model(model), and myocardial infarction model + TMAO(model + TMAO). TMAO and model + TMAO group received 0.24 % TMAO in drinking water for one month. After modeling, echocardiography assessed cardiac function, and cardiac tissues were collected for analysis. Masson staining observed collagen deposition, while immunohistochemistry was conducted to identify fibronectin, collagen III, collagen I, and JAK/STAT pathway related proteins levels. In vitro, mouse cardiac fibroblasts were cultured and treated with varying TMAO concentrations (0, 300, 600, 900 μM), and Western blot was carried out to analyse changes in fibronectin, collagen III, and collagen I. Subsequently, the JAK2/STAT3 pathway inhibitor AG490 was utilized to treat cells and further examine the changes of fibronectin and collagen. The in vivo data showed TMAO significantly increases fibrosis and upregulates fibronectin, collagen III, and collagen I. In vitro experiments indicated that TMAO promotes fibronectin, collagen III, and collagen I levels through regulating the JAK2/STAT3 pathway, ultimately accelerating fibrosis.
研究领域:
心血管疾病研究
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分子生物学
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产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2022
·
IF 4.331
Hui Zhang,Yi Li,Junping Miao,Xinran Zhu,Jing Yang,Qinglei Zhang,Yanfu Yang,Junqiang Zhao,Yunxia Hu,Yiping Zhao,Li Chen
N-Oxide zwitterionic polyethyleneimine (ZPEI), a new kind of aqueous phase monomer synthesized by commercially branched polyethyleneimine (PEI) via oxidation reaction, was prepared for fabrication of thin-film composite (TFC) polyamide membranes via interfacial polymerization. The main factors, including the monomer concentration and immersion time of the aqueous phase and organic phase, were investigated. Compared with PEI-TFC membranes, the obtained optimal defect-free ZPEI-TFC membranes exhibited a lower roughness (3.3 ± 0.3 nm), a better surface hydrophilicity, and a smaller pore size (238 Da of MWCO). The positively charged ZPEI-TFC membranes (isoelectric point at pH 8.05) showed higher rejections toward both divalent cationic (MgCl2, 93.0%) and anionic (Na2SO4, 96.1%) salts with a water permeation flux of up to 81.0 L·m–2·h–1 at 6 bar, which surpassed currently reported membranes. More importantly, mainly owing to N-oxide zwitterion with strong hydration capability, ZPEI-TFC membranes displayed a high flux recovery ratio (97.0%) toward a model protein contaminant (bovine serum albumin), indicating good anti-fouling properties. Therefore, the novel N-oxide zwitterion functionalized positively charged nanofiltration membranes provide an alternative for water desalination and sewage reclamation.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2023
·Vol. 24
·期 10
·8767
·
IF 5.6
Shuo Gao,Xiao Lin,Yeqin Shi,Hu Zhou,Xiao Zheng,Mingyu Li,Ting Lin
A new prenylated indole alkaloid—Penicimutamide CN-oxide (1), a new alkaloid penicimutamine A (2), along with six known alkaloids were isolated from an endophytic fungusPallidocercospora crystallina. A simple and accurate method was used to determine the N-O bond in theN-oxide group of1. By using a β-cell ablation diabetic zebrafish model, compounds1,3,5,6and8showed significantly hypoglycemic activities under the concentration of 10 μM. Further studies revealed that compounds1and8lowered the glucose level through promoting glucose uptake in zebrafish. In addition, all eight compounds showed no acute toxicity, teratogenicity, nor vascular toxicity in zebrafish under the concentrations range from 2.5 μΜ to 40 μM. Importantly, these results provide new lead compounds for the development of antidiabetes strategies.Keywords:prenylated indole alkaloid;N-oxides;endophytic fungus;hypoglycemic activity;zebrafish
研究领域:
药物化学
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生物化学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Hao Zhang,Xueling Xu,Guangyao Zhang,Jie Yang,Yi Lu
Developing active and stable electrocatalysts for oxygen evolution reaction is of great significance to generate oxygen and hydrogen by seawater electrolysis, which however remains some issues that high energy consumption and chloride corrosion. Here we pioneered a polymer/inorganic hybrid engineering strategy for achieving excellent salt resistance solar evaporation and oxygen evolution performance (OER). The La 0.9 Sr 0.1 CoO 3 /nickel foam–cellulosic aerogel (LSC1/NF–CA) was synthesized by engineering Trimethylamine N–oxide (TMAO) polymer brush onto the surface of hybrid aerogels composed of La 0.9 Sr 0.1 CoO 3 /Ni foam (LSC1/NF) and cellulose/polyvinyl alcohol, which has good hydrophilic features, intrinsic solar capture capacity, and stable OER performance in seawater. Benefiting from the synergy of solar desalination with surface hydration effect of TMAO, the LSC1/NF–CA presents a superior catalytic activity , requiring a lower overpotential of 341 mV and a tafel slope of 58.2 mV dec −1 at 10 mA cm −2 under 6.0 sun illumination . Our results establish a new strategy that can guide the design of stable and efficient polymer/inorganic hybrid catalysts, which shows a promising prospect as alternatives to noble metal–based catalysts for seawater splitting.
研究领域:
材料科学
·
催化化学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）