INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2021
·Vol. 22
·期 16
·8668
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IF 5.924
Jie Li,Shiyi Wang,Huayin Li,Yuan Tan,Yunjie Ding
The synthesis of ester compounds is one of the most important chemical processes. In this work, Zn-Mg-Al mixed oxides with different Zn2+/Mg2+molar ratios were prepared via co-precipitation method and supported gold nanoclusters to study the direct oxidative esterification of aldehyde and alcohol in the presence of molecular oxygen. Various characterization techniques such as N2-physical adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and CO2temperature programmed desorption (TPD) were utilized to analyze the structural and electronic properties. Based on the results, the presence of small amounts of Zn2+ions (~5 wt.%) provoked a remarkable modification of the binary Mg-Al system, which enhanced the interaction between gold with the support and reduced the particle size of gold. For oxidative esterification reaction, the Au25/Zn0.05MgAl-400 catalyst showed the best performance, with the highest turnover frequency (TOF) of 1933 h−1. The active center was believed to be located at the interface between metallic gold with the support, where basic sites contribute a lot to transformation of the substrate.Keywords:gold catalyst;cluster;hydrotalcite;oxidative esterification;methyl isobutyrate
研究领域:
化学工程
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催化材料
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DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2018
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IF 2.631
Qian Zeng,Biao Hu,Hongye Cheng,Lifang Chen,Junmei Huang,Zhiwen Qi
Isobutyl isobutyrate is an important chemical which can be formed in a reactive extraction process with ionic liquid as dual solvent-catalyst. To design such an intensified process, the liquid-liquid equilibria (LLE) data for the esterification system involving ionic liquid are essential. In this work, the LLE of ternary systems {isobutyl isobutyrate (IBIBE) + isobutyric acid (IBAc) or isobutanol (IBOH) + 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIm][HSO 4 ])} and the quinary system {IBAc + IBOH + IBIBE + H 2 O + [BMIm][HSO 4 ]} were measured at temperature T = (298.2, 323.2 and 353.2) K, T = (323.2, 333.2, 343.2 and 353.2) K and atmospheric pressure, respectively. Based on the experimental data, the solute distribution coefficient and the selectivity were determined, which confirms the feasibility of the ionic liquid for isobutyl isobutyrate formation. The phase behaviour was explained by the molecular interaction using σ -potential analysis. Moreover, the binary parameters of the NRTL model for [BMIm][HSO 4 ] catalysed isobutyl isobutyrate formation system were fitted.
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 PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
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2025
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IF 3.1
Lin Chen,Han Huang,Xiali Liu,Peijing Zhao,Biao Zhou
A novel oxyphenisatin analogue was identified in a type of jelly candy during routine inspections of food products marketed for weight-loss purposes. Through analysis utilizing ultra-high-performance quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS), the fragment ions at m/z 258 and 195 observed in the MS/MS experiments were found to be consistent with those of 4-Chloro-oxyphenisatin diacetate. It was inferred that the unknown compound is likely a derivative of 4-Chloro-oxyphenisatin diacetate. The candy was separated and purified by column chromatography, and the purified compound was determined to be 96.4 % by high-performance liquid chromatography (HPLC). Subsequently, the structure was confirmed through nuclear magnetic resonance (NMR) spectroscopy. Based on the data, it was concluded that the structure of the unknown compound involved the substitution of two symmetrical acetyl groups in the 4-chloro-oxyphenisatin diacetate molecule with two isobutyl groups. Ultimately, the novel oxyphenisatin analogue was identified as (5-chloro-2-oxoindolin-3,3-ylidene) bis (4,1-phenylbutan-2-yl) diisobutyrate and designated as 4-Chloro-oxyphenisatin diisobutyrate. Finally, a quantitative analysis of the novel unknown compound in the jelly candy revealed a concentration of 6 mg per pellet. Based on the recommended daily consumption of one pellet, as indicated on the product packaging, the level of illegal additives may lead to diarrhoea and consequently poses a risk to human health. To the best of our knowledge, this represents the first report on the identification of 4-Chloro-oxyphenisatin diisobutyrate.
研究领域:
药物化学
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食品安全
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分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2024
·
IF 2.2
Erkang Li,Jiajun Wei,Lei Li,Xinlei Niu,Yulin Shao,Yingmin Yu
To prevent the wastewater containing 2-ethoxyethanol (2EE) from causing environmental pollution and economic waste, liquid–liquid extraction was used to recover 2-ethoxyethanol from wastewater in this study. The liquid–liquid equilibrium behavior of water + 2-ethoxyethanol + four solvents (propyl acetate, isopropyl acetate, n-butyl acetate, and isobutyl acetate) was investigated at 303.2 K and atmospheric pressure. The distribution coefficient ( D ) and separation factor ( S ) were used to compare and discuss the extraction efficiency of each system. The results indicated that all esters could effectively separate 2-ethoxyethanol from water. Among them, isobutyl acetate exhibited the highest values for D and S , demonstrating its superior separation capability. The experimental data were correlated with the thermodynamic model and interaction parameters were obtained. These parameters were verified using the GUI-MATLAB tool, and all four systems passed validation, confirming the reliability of the obtained binary interaction parameters. Furthermore, the root mean square deviation ( RMSD ) was used to assess the deviation between the experimental and regression values. The RMSD values for the NRTL and UNIQUAC models were 0.008 and 0.007, respectively. The interactions between 2-ethoxyethanol and water or esters were explored using σ-Profile, and it was found that esters with a branched chain structure provided better extraction. To explain the properties of the extractants microscopically, the interaction energies between 2-ethoxyethanol molecules and water or ester molecules, as well as the non-bonding energies of 2-ethoxyethanol in different media, were calculated.
研究领域:
环境工程
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化学工程
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热力学
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物理化学
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产品关联
DOI
高影响因子
JOURNAL OF PEST SCIENCE
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2020
·Vol. 94
·期 2
·463-472
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IF 4.578
Xu Hao,Zhao Jiajia,Li Faqian,Yan Qi,Meng Ling,Li Baoping
Riptortus pedestris (Fab.) is an important pest on soybean plants in East Asia. Females lay eggs scattered not only on host plants, but also on non-host plants, probably for avoiding detection by natural enemies. Newly hatched nymphs can develop to the second instar without the need of food except water. Second instar nymphs, the first-feeding stage with a strong locomotion, need to find suitable feeding sites on host plants. The mechanism is still not well understood. Here, we found second instars were attracted by both male and female adults, but generally repelled by second and fifth instar nymphs, wherein their responses were little affected by food volatiles (soybean seeds or seedlings). Nymphs distinctly differed from adults in chemical composition of the whole-body extracts. 4-oxo-( E )-2-Hexenal was the major component in nymph’s extracts, but it was not found in adults, whereas some ester compounds, such as ( E )-2-hexenyl esters, were exclusively found in adults and accounted for the main part in their extracts. The three esters, ( E )-2-hexenyl ( Z )-3-hexenoate (E2-6:Z3Hx), ( E )-2-hexenyl ( E )-2-hexenoate (E2-6:E2Hx) and myristyl isobutyrate, were male specific and had been reported as an aggregation pheromone. Synthetic 4-oxo-( E )-2-hexenal strongly repelled second instars, while ( E )-2-hexenyl hexanoate emitted by both males and females attracted them. The main component of the aggregation pheromone, myristyl isobutyrate, also strongly attracted second instars. How the findings may improve the efficiency of chemical traps in fields was discussed.
研究领域:
昆虫学
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化学生态学
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害虫管理
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2025
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IF 2.1
He Ma,Houchun Yan,Menghao Du,Yingmin Yu,Qingsong Li
To separate methyl 2-hydroxyisobutyrate from an aqueous solution, alkyl alcohols were selected as extractants. The liquid–liquid equilibrium data for the system {water + methyl 2-hydroxyisobutyrate + extractants (1-hexanol, 1-heptanol, 1-octanol, and 1-nonanol)} were determined at a temperature of 303.2 K. The partition coefficients and separation factors were calculated to assess the effectiveness of the extraction process. Additionally, the data were correlated using the NRTL and UNIQUAC models, with parameter regression conducted accordingly. The GMcal_TieLinesLL tool was utilized to evaluate the regression model parameters, and the results conformed to the Gibbs stability criterion. The present study further investigates the separation mechanism through analyses of σ-profile, deformation charge density, interaction energies, and Reduced Density Gradient (RDG) analysis. Ultimately, it was concluded that 1-nonanol exhibited the most effective extraction performance.
研究领域:
化学工程
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分离过程
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物理化学
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热力学
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萃取
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分子建模
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产品关联
DOI
高影响因子
Journal of Functional Foods
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2021
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IF 4.451
Xiang-Rong Cheng,Piao-Han Tu,Wen-Le Dong,Bu-Tao Yu,Shu-Fang Xia,Mitchell N. Muskat,Bin Guan
Xiaoheiyao , the rhizomes of Inula nervosa Wall., is a culinary spice known to contain some electrophilic Nrf2 activators that could potentially intervene in nonalcoholic fatty liver disease (NAFLD). In this study, the electrophilic components from Xiaoheiyao were annotated by comprehensive cheminformatics analyses on UHPLC-MS/MS data after being knocked out with glutathione (GSH)-immobilized magnetic microspheres. Their intervention effects against hepatic steatosis were investigated in free fatty acid (FFA)-treated HepG2 cells. The electrophilic components in Xiaoheiyao were found to be the major bioactive components preventing hepatic steatosis in FFA-treated HepG2 cells. In particular, 10-isobutyryloxy-8,9-epoxythymol isobutyrate (XHY-1) improved hepatic lipid metabolism disorder, Krebs cycle activity, oxidative phosphorylation, and the cellular and mitochondrial redox status. Moreover, XHY-1 activates the Nrf2-ARE signaling pathway through the up-regulation of Nrf2 expression and promotion of Nrf2 nuclear translocation. Molecular docking further showed that XHY-1 could conjugate with Cys151 in the BTB domain of Keap1 through the epoxy group. In conclusion, the electrophilic components of Xiaoheiyao , especially XHY-1, attenuated hepatic steatosis in FFA-treated HepG2 cells through activation of the Nrf2-ARE signaling pathway.
研究领域:
药理学
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细胞生物学
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分子生物学
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药物化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）