MOLECULES
·
2015
·Vol. 20
·期 10
·19393-19405
·
IF 2.416
Yongkang Gai,Zhongping Hu,Zhao Rong,Xiang Ma,Guangya Xiang
The preparation of triazamacrocyclic hydroxypyridinonate (HOPO-TACN) derivatives as potential chelators for metals in biomedical applications was reported. The synthesis is based on a convergent synthetic approach, in which the key intermediate di-tert-butyl-2,2′-(1,4,7-triazonane-1,4-diyl) diacetate was coupled with a hydroxypyridinonate pendant arm. The method is suitable for rapid syntheses of metal chelator HOPO-TACNs of biomedical interest.Keywords:1,4,7-triazonane;hydroxypyridinonate;metal chelator
研究领域:
生物化学
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医学化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2018
·
IF 6.759
Weiwei Yu,Xinwen Guo,Chunshan Song,Zhongkui Zhao
The controlled visible-light mediated conversion of nitroaromatics to versatile nitrogen-containing intermediates is of great significance but still remains a challenge. Herein, we report for the first time a facile visible-light-initiated one-pot strategy for clean and efficient synthesis of nitrone from nitrobenzene and benzyl alcohol. It integrates the controlled photocatalytic reduction of nitrobenzene to phenylhydroxylamine by photogenerated electrons with the selective photocatalytic oxidation of benzyl alcohol to benzaldehyde by photoinduced holes over a low-cost CdS photocatalyst with a suitable reduction capability, followed by spontaneous condensation of the as-formed hydroxylamine and aldehyde at ambient pressure and room temperature. Furthermore, by modulating cocatalyst and illumination time, for the conversion of the same reactants, the other two useful nitrogen-containing compounds, imine and secondary amine, were also successfully synthesized. The reaction mechanisms for flexible synthesis of the three target products are proposed.
研究领域:
化学合成
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光催化反应
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2012
·
IF 3.07
Peng Liao,Songhu Yuan,Wenbiao Zhang,Man Tong,Kun Wang
Adsorption of three nitrogen-heterocyclic compounds (NHCs), pyridine, indole, and quinoline, on a new porous carbonaceous adsorbent, bamboo charcoal (BC), is investigated. Different structures and surface properties of BC are created by HNO 3 and NaOH treatment as well as by microwave (MW) radiation. HNO 3 treatment decreases surface area, micropore volume, and surface hydrophobicity, whereas NaOH treatment increases surface area and micropore volume. MW treatment dramatically increases hydrophobicity and fraction of aromatic structure. Adsorption isotherms of NHCs are nonlinear and better fitted by Freundlich model (FM) compared with Langmuir model (LM) and Polanyi–Manes model (PMM). The maximum adsorption capacities for pyridine, indole, and quinoline reach 42.92, 93.24, and 91.74 mg g −1 , respectively, at an initial concentration of 200 mg L −1 . Surface area, hydrophobicicty, and electrostatic and π – π electron-donor–acceptor (EDA) interactions are accountable for NHC adsorption. A model relating NHC adsorption (log K ) and adsorbent–adsorbate physicochemical properties is developed to measure the relative contribution of these interactions giving the sequence of surface area > hydrophobic interaction > electrostatic interaction > π – π EDA interaction.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2020
·Vol. 25
·期 4
·948
·
IF 3.267
Yuqin Yang,Tianxin Xie,Xuehao Tian,Nana Han,Xiaojing Liu,Hongshan Chen,Jinchai Qi,Feng Gao,Wen Li,Qianwen Wu,Su Huo,Yuhao Gu,Ziqi Dai,Penglong Wang,Haimin Lei
Betulinic acid (BA) is a star member of the pentacyclic triterpenoid family, which exhibits great prospects for antitumor drug development. In an attempt to develop novel antitumor candidates, 21BA-nitrogen heterocyclic derivatives were synthetized, in addition to four intermediates, 23 of which were first reported. Moreover, they were screened for in-vitro cytotoxicity against four tumor cell lines (Hela, HepG-2, BGC-823 and SK-SY5Y) by a standard methylthiazol tetrazolium (MTT) assay. The majority of these derivatives showed much stronger cytotoxic activity thanBA. Remarkably, the most potent compound7e(the half maximal inhibitory concentration (IC50) of which was 2.05 ± 0.66 μM) was 12-fold more toxic in vitro thanBA-treated Hela. Furthermore, multiple fluorescent staining techniques and flow cytometry collectively revealed that compound7ecould induce the early apoptosis of Hela cells. Structure–activity relationships were also briefly discussed. The present study highlighted the importance of introducing nitrogen heterocyclic rings into betulinic acid in the discovery and development of novel antitumor agents.Keywords:betulinic acid;BA-nitrogen heterocyclic derivatives;antitumor;Hela;flow cytometry
研究领域:
药物化学
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肿瘤学
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细胞生物学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Wentao Zheng,Jialing Chen,Yujiao Jia,Nengqi Sun,Shiping Wang,Xianku Wu,Xuehua Zhang
A series of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU)/N-heterocyclic DESs aqueous solutions were designed and synthesized as CO 2 capture agents. They showed excellent performance in absorption capacity, especially for the low-pressure CO 2 . The CO 2 loads in the absorbents were higher than 1.0 mol/mol when the pressure was just 0.1 bar. Through a combination of 13 C NMR spectra, FT-IR spectra and absorption experiments, a novel absorption mechanism was proposed. It was the shuttling role of the carbamate generated from CO 2 and nitrogen heterocycles, along with the synergistic roles of the DBU and water, that caused the high absorption capacity of the DBU/N-heterocyclic DESs for CO 2 . Meanwhile, the thermodynamic parameters, the activation energy and the regeneration efficiency were all measured to estimate the absorption performance of the DBU/N-heterocyclic DESs aqueous solutions for low-concentration CO 2 .
研究领域:
化学
·
环境科学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Kui Wu,Ya Jun Li
The solubility and solution thermodynamics of azacyclotridecan-2-one in different solvents are indispensable for the purification and performance improvement of crystalline products in industry. In this paper, the solid–liquid equilibrium of azacyclotridecan-2-one in 15 pure solvents (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, ethyl acetate, acetone, toluene, acetonitrile, dichloromethane, 1,2-dichlorobenzene, cyclohexanone, and tetrahydrofuran) from 273.15 to 323.15 K at atmospheric pressure was measured. The mole fraction solubility increased with the increase in temperature in all solvents studied. The modified Apelblat equation, Van’t Hoff equation, Buchowski–Ksiazczak λh equation, and nonrandom two-liquid (NRTL) activity coefficient model were used to correlate the experimental data. Consequently, some association parameters were obtained. As a result, the NRTL model provided the best fitting. The solubility data provide the basic data for the design and optimization of the azacyclotridecan-2-one crystallization process.
研究领域:
化学工程
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物理化学
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2012
·
IF 3.07
Peng Liao,Songhu Yuan,Wenjing Xie,Wenbiao Zhang,Man Tong,Kun Wang
The adsorption kinetics and thermodynamics of nitrogen-heterocyclic compounds (NHCs), pyridine, indole and quinoline, in aqueous solutions on bamboo charcoal (BC), as well as the regeneration of spent BC by microwave radiation, are investigated. BC is produced by incomplete combustion of moso bamboo at high temperature and nitrogen atmosphere. Adsorption kinetics is analyzed using pseudo-first-order and pseudo-second-order as well as Weber–Morris model. The results show that NHC adsorption on BC is predominantly regulated by surface diffusion in initial 1 h followed by intraparticle diffusion in later stage. BC exhibits a strong adsorption affinity to NHCs, and the adsorption isotherms are well described by Freundlich model. Thermodynamic analysis indicates that the adsorption is spontaneous and endothermic. Adsorption site energy analysis illustrates a distribution of adsorption energy, which indicates the heterogeneous sites on BC for NHC adsorption. Furthermore, spent BC with NHC adsorption can be effectively regenerated by MW radiation. The adsorption capacity becomes even higher than that of virgin BC after five times of adsorption–regeneration cycles. This study proves BC is a promising adsorbent for NHC removal in wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Shijie Wang,Shenghan Zhang,Zhenye Zhang,Xinliang Guo,Yu Tan,Kexin Liang,Xijun Wang
Liquid organic hydrogen carrier (LOHC) has been recognized as a highly promising candidate for hydrogen storage materials in addressing hydrogen utilization issues. However, the hydrogenation and dehydrogenation of LOHC typically require noble metal catalysts and harsh reaction conditions. In this paper, we proposed an efficient reversible electrochemical hydrogen storage system based on a nitrogen heterocyclic organic hydrogen carrier, quinoxaline , in which water was used as the solvent and hydrogen source for quinoxaline hydrogenation, and a self-supporting dendritic P-WO 3 /NF electrode was employed as the electrocatalyst. The catalytic properties of P-WO 3 /NF for electrochemical hydrogenation of quinoxaline and dehydrogenation of 1,2,3,4-tetrahydroquinoxaline were studied in 1 M KOH solution under mild conditions. The results showed that the hydrogenation conversion of quinoxaline was 90%, the selectivity was 99%, and the dehydrogenation conversion of 1,2,3,4-tetrahydroquinoxaline was 100%, the selectivity was 100%. This indicates that the system has high conversion efficiency, outstanding selectivity, and good reversibility. Meanwhile, the P-WO 3 /NF electrode adapted to the system exhibited good catalytic stability. In addition, no pre-prepared external hydrogen was required in the electrochemical hydrogenation reaction involving water, which gave the system an excellent safety profile. The reversible electrochemical hydrogen storage system established by this work broadens the vision of LOHC in hydrogen storage applications.
研究领域:
材料科学
·
能源化学
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DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2014
·Vol. 38
·期 1
·60-66
·
IF 2.594
Kai Hu,Zhifen Deng,Bei Wang,Yongxia Cui,Mingsan Miao,Wei Liu,Qiong Jiang,Wenjie Zhao,Yanjie Huang,Shusheng Zhang
A new stationary phase for high-performance liquid chromatography was prepared by covalently bonding a heteroatom-bridged cyclophane onto silica gel using 3-aminopropyltriethoxysilane as the coupling reagent. The structure of the new material was characterized by infrared spectroscopy, elemental analysis, and thermogravimetric analysis. The linear solvation energy relationship method was successfully employed to evaluate the new phase with a set of 25 solutes, and compared with octadecylsilyl and p - tert -butyl-calix[4]arene bonded stationary phases. The retention characteristics of the new phase are similar to the octadecylsilyl and conventional calixarene phases, and it also has distinctive features. In addition, the chromatographic behavior of the phase was illustrated by eluting alkylbenzenes and inorganic anions in the reversed-phase mode and anion-exchange mode, respectively. Thus, multi-interaction mechanisms and mixed-mode separation of the new phase can very likely guarantee its promising application in the analysis of complex samples. The column has been successfully employed for the analysis of triazines in milk, and it is demonstrated to be a competitive alternative analytical method for the determination of triazine herbicide residues.
研究领域:
化学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yanan Li,Jian Cao,Chuanxiao Wang,Yiyi Qiao,Jiayu Gao,Linlin Wang,Xiao Zhang,Le Wang,Yuanhao Li,Zhicheng Zuo
Serum albumin is the most abundant protein in mammalian plasma. It occupies an extremely important position in organisms as an early indicator of the development of many diseases. The development of fluorescence sensing technology has revolutionized the drawbacks of traditional methods. In this strategy, we designed and synthesized three dual fluorophore organic sensors TPA-IPA-T1, TPA-QL-T2, and TPA-Py-T3 for the detection of serum albumin. The rotation of the C–C bond of sensors is restricted and the molecular structure forms a rigid plane that contributes to the fluorescent emission intensity of the sensor. The fluorescent skeletons were successfully constructed by triphenylamine composed the electron-withdrawing nitrogen-containing compounds benzopyrrole (indole), benzopyridine (quinoline), and pyridine, respectively, with piperazine as a rigid connecting bridge. The addition of human serum albumin (HSA) turned on the fluorescent emission of the sensor near 580–600 nm. The color of the sensor solution changed from colorless to pink and bright orange, respectively. The fluorescent intensity increased by 24, 67, and 31 fold, respectively. The sensors have the advantages of sensitivity and fast response, strong anti-interference ability, low detection limit and good water solubility. Drug experiments in artificial urine demonstrate the characteristics of sensors, which has a very high potential for biological feasibility and medical applications. The sensors facilitaty the binding of the HSA through electrostatic interactions. The sensors were explored to be able to efficiently bind the IB structural domain of HSA, which had a good meaningful of avoiding the interference of commonly drugs in clinical medicine and in artificial urine on the detection of HSA.
研究领域:
生物化学
·
医学诊断
·
分析化学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2015
·
IF 3.34
Feifei Sun,Qingni Yu,Jingke Zhu,Lecheng Lei,Zhongjian Li,Xingwang Zhang
Based on the solubility of 25 nitrogen-heterocyclic compounds (NHCs) measured by saturation shake-flask method, artificial neural network (ANN) was employed to the study of the quantitative relationship between the structure and pH-dependent solubility of NHCs. With genetic algorithm-multivariate linear regression (GA-MLR) approach, five out of the 1497 molecular descriptors computed by Dragon software were selected to describe the molecular structures of NHCs. Using the five selected molecular descriptors as well as pH and the partial charge on the nitrogen atom of NHCs ( Q N ) as inputs of ANN, a quantitative structure–property relationship (QSPR) model without using Henderson–Hasselbalch (HH) equation was successfully developed to predict the aqueous solubility of NHCs in different pH water solutions. The prediction model performed well on the 25 model NHCs with an absolute average relative deviation (AARD) of 5.9%, while HH approach gave an AARD of 36.9% for the same model NHCs. It was found that Q N played a very important role in the description of NHCs and, with Q N , ANN became a potential tool for the prediction of pH-dependent solubility of NHCs.
研究领域:
药物化学
·
计算化学
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DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2021
·
IF 4.889
Ke Cai,Hanlun Wu,Tao Hua,Chaoqiang Liao,Hao Tang,Lingyun Wang,Derong Cao
Four novel D-A-π-A metal-free organic sensitizers QL1 – 4 with the fused azacycle units as donors have been designed and synthesized to investigate the relationship between both the sizes and conjugations of azacycle and performances of dye-sensitized solar cells systematically. QL1 with the five-membered azacycle, i.e., with carbazole ( Cz ) as donor, exhibits the smallest molar extinction coefficients ( ε ). QL2 and QL3 with the seven-membered azacycle, i.e. with N -phenyl-iminostilbene ( ISB ) and N -phenyl-iminodibenzyl ( IDB ) as donors, respectively, show the red-shifted absorption spectra and higher ε compared to QL1 . However, QL2 and QL3 with an only distinction in a single or double bond, display distinctive PCEs. QL4 with the six-membered azacycle, i.e., 9,9,10-triphenyl-9,10-dihydroacridine ( TDD ), exhibits a blue-shifted absorption spectrum due to a big dihedral angle , resulting in a lower photovoltaic performance . Especially, QL3 with the ISB donor is conducive to achieving a PCE of 6.22%, which is higher than QL2 , due to its better planar structure and more conjugation. When co-adsorbed with CDCA, QL3 exhibits the highest PCE of 7.14% among all dyes, and up to 8.26% by co-sensitizing with dye WL5 , which surpasses that of the reference dye N719 (7.75%). The results indicate that the size and conjugation of the fused azacycle donors may affect the photovoltaic performance significantly, and the ISB unit is demonstrated as a promising donor for efficient organic dyes.
研究领域:
材料科学
·
有机化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）