Molecular Catalysis
·
2023
·
IF 4.6
Xuan Gao,Zhihui Li,Dongsheng Zhang,Baoquan Zhang,Yanji Wang
Efficient and safe conversion of 5-hydroxymethylfurfural (HMF) to 5-hydroxymethyl-2-furancarbonitrile (HMFC) with hydroxylamine zinc chloride salt (ZnCl 2 ·2NH 2 OH) obtained from a novel method was developed. Without a catalyst, free NH 2 OH could react with HMF to produce HMFC with a yield of 41% at 55 °C. ZnCl 2 was an appropriate catalyst that increased HMFC yield to 64%. However, the reaction has a potential explosion safety hazard and a low effective utilization rate of NH 2 OH due to the easy decomposition property of free NH 2 OH. To address these issues, ZnCl 2 ·2NH 2 OH was prepared to serve as a hydroxylamine stabilizer, catalyst, and nitrogen source in the synthesis of HMFC. Therefore, NH 2 OH could be slowly released to participate in the reaction, slowing the invalid decomposition and increasing the utilization rate of elemental N. Under optimal conditions of n(HMF): n(NH 2 OH) = 1:1.5, 100 °C for 20 min with acetonitrile as solvent, the yield of HMFC was 100%. A plausible reaction mechanism for HMFC synthesis was also proposed.
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Food Science and Human Wellness
·
2023
·
IF 7
Xiaoyu Chen,Hongyuan Zhao,Fanqiang Meng,Libang Zhou,Zhaoxin Lu,Yingjian Lu
Type 2 diabetes mellitus (T2DM) is associated with liver dysfunction and intestinal dysbiosis. Bioactive peptides (BAPs) have been reported to ameliorate T2DM by preventing oxidative damage to the liver. Bacillus amyloliquefaciens fmb50 produces the lipopeptide surfactin with a wide range of biological activities. The effects of surfactin on T2DM, on the other hand, have not been studied. In the present study, 80 mg/kg body weight surfactin supplementation lowered fasting blood glucose (FBG) levels by 21.05 % and insulin resistance (IR) by 18.18 % compared with those in the T2DM group, reduced inflammation, and increased antioxidant activity in mice with T2DM induced by a high-fat diet (HFD) and streptozotocin (STZ). According to further research, surfactin administration reduced Firmicutes-to-Bacteroidetes ratios while increasing Bifidobacterium abundance by 20 times and the level of the tight junction protein Occludin by 18.38 % and ZO-1 by 66.60 %. Furthermore, surfactin also improved hepatic glucose metabolism by activating the adenosine monophosphate-activated protein kinase (AMPK) signalling pathway, increasing glycogen synthesis and glucose transporter 2 (GLUT2) protein expression while reducing glucose-6-phosphatase (G6Pase) protein expression. In addition, the increased Bifidobacterium abundance indirectly reduced the liver burden of the metabolic products indole, cresol and amine produced by saprophytic bacteria. All of these findings revealed that surfactin not only ameliorated HFD/STZ-induced gut dysbiosis and preserved intestinal barrier integrity but also enhanced hepatic glucose metabolism and detoxification function in T2DM mice. The gut microbiota appeared to be important in controlling glucose metabolism, IR, fat accumulation, inflammation and antioxidation, according to Spearman’s correlation coefficients. All data indicated that surfactin alleviated hyperglycaemia in mice with T2DM induced by HFD/STZ.
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CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Tao Luo,Yanan Yuan,Danna Zhou,Liting Luo,Jinjun Li,Feng Wu
In the recent years, sulfite-induced oxidation of various contaminants using oxysulfur radicals (SO 4 − , SO 5 − and SO 3 − ) has been explored to establish novel advanced oxidation processes (AOPs). Although transition metals, such as cupric ions (Cu(II)), have been demonstrated to be capable of activating sulfite (S(IV)), the catalytic mechanism of the specific Cu(II) species is still not very clear. In this work, N-acetyl- para -aminophenol (APAP) was used as a basic substrate to investigate the process, mechanism and stability of the Cu(II)-S(IV) system with low dosages of Cu(II) (0.010 mmol L −1 ) in an alkaline solution (pH 10). The results show that 0.010 mmol L −1 Cu(II) can efficiently activate S(IV) for the oxidation of APAP and other contaminants (e.g., metoprolol, sulfanilamide, aniline, 4-chloroaniline, N,N-dimethylaniline, p -nitrophenol and 3-nitrophenol). Simulation calculations for the distribution of the Cu(II) species and pH-dependence of APAP oxidation in the Cu(II)-S(IV) system showed that Cu(OH) 2 particles are the major active species in the catalysis of S(IV). The surface complexation of S(IV) with the Cu(OH) 2 particles prior to the production of oxysulfur radicals is the basic mechanism of the alkaline Cu(II)-S(IV) system. Radical inhibition with scavengers (ethanol, tert-butyl alcohol or aniline) demonstrates that SO 5 − , SO 4 − and hydroxyl radicals (HO ) are responsible for the contaminant oxidation. Moreover, SO 5 − is believed to be the main active species in the Cu(II)-S(IV) system, which has a second-order rate constant of 2.98 × 10 8 M −1 s −1 with APAP. This work renews our recognition of the Cu(II)-S(IV) system applications and further understanding of the catalytic role of the nascent Cu(OH) 2 particles in the activation of S(IV).
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Chemical Engineering and Processing-Process Intensification
·
2018
·
IF 2.826
Yanyan Guo,Chengna Dai,Zhigang Lei
A series of Pd-La/SiO 2 /cordierite (cordierite = COR) and Pd-Zn/SiO 2 /COR bimetallic monolithic catalysts were prepared, characterized, and tested for the hydrogenation of 2-ethylanthraquinone (eAQ) as the key step of anthraquinone method for production of H 2 O 2 . It was found that the metal particle size is remarkably dependent on the Pd/M (M = La, and Zn) mass ratio of bimetallic monolithic catalysts. By virtue of its small metal particle size and the strong interaction, the 0.8% Pd-0.4% La/SiO 2 /COR monolithic catalyst presents the highest H 2 O 2 yield (7.7 g L −1 ) and selectivity toward active quinones (95%), which is attributed to the addition of La leading to the synergistic effect between Pd and La. Moreover, the density functional theory (DFT) calculations for the adsorption of eAQ over the surface of Pd-La/SiO 2 /COR and Pd-Zn/SiO 2 /COR bimetallic monolithic catalysts have been conducted to further understand the mechanism of molecule–surface interactions between eAQ and the PdM(1 1 1) or Pd(1 1 1) surfaces. Detailed studies showed that the high catalytic activity of Pd-La/SiO 2 /COR bimetallic monolithic catalyst is attributed to the stronger adsorption between Pd 3 La 1 (1 1 1) and the carbonyl group of eAQ.
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Minerals
·
2018
·Vol. 9
·期 1
·15
·
IF 1.835
Bin Luo,Junbo Liu,Quanjun Liu,Chao Song,Li Yu,Shimei Li,Hao Lai
Zinc is mostly extracted from oxidized zinc and zinc sulfide minerals, and this process involves flotation as a key step. While it is easier to float the sulfide mineral, its consumption and depletion has led to an increased reliance on oxidized zinc minerals, including smithsonite. Hence, the development of efficient ways of collecting smithsonite by flotation is an important objective. Herein, we describe the use of 2-(hexadecanoylamino)acetic acid (HAA), a novel surfactant, as a collector during smithsonite flotation. The mechanism and flotation performance of HAA during smithsonite flotation was investigated by total organic carbon (TOC) content studies, zeta potential measurements, Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) analyses, combined with microflotation experiments. The flotation results revealed that HAA was an excellent collector in pulp over a wide pH range (9–12) and at a relatively low concentration (2 × 10−4mol/L), at which a recovery of close to 90% of the smithsonite mineral was obtained. TOC content studies revealed that the good flotation recovery was ascribable to large amounts of collector molecule adsorbed on the smithsonite surface, while zeta potential measurements showed that the HAA was chemically adsorbed onto the smithsonite. FTIR and XPS analyses revealed that the HAA collector molecules adsorbed onto the smithsonite surface as zinc–HAA complexes involving carboxylate moieties and Zn sites on the smithsonite surface in alkaline solution.Keywords:smithsonite;flotation;2-(hexadecanoylamino)acetic acid;collector;adsorption
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JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2018
·Vol. 99
·期 6
·3192-3202
·
IF 2.379
Zhisheng Zhou,Xing Hu,Guowen Zhang,Rui Wang,Deming Gong
BACKGROUND 5-Hydroxymethyl-2-furaldehyde (5-HMF), a by-product of the Maillard reaction, usually present in fried and baked food, may cause potential harm to the human body. Here, the interaction between 5-HMF and calf thymus DNA (ctDNA) under physiological buffer (pH 7.4) was studied using multi-spectroscopic methods combined with multivariate curve resolution–alternating least squares (MCR-ALS) chemometrics and molecular simulation techniques. RESULTS The concentration profiles and pure spectra of the three components (5-HMF, ctDNA and 5-HMF–ctDNA complex) were extracted from highly overlapping spectra using MCR-ALS analysis, which verified the formation of 5-HMF–ctDNA complex. The binding constant being of the order of 10 3 L mol −1 at four temperatures (292, 298, 304 and 310 K) indicated a weak affinity in the binding of 5-HMF to ctDNA. The binding interaction was mainly driven by hydrogen bonds and van der Waals forces. Viscosity analysis, melting assay, ionic strength effect and competitive fluorescence studies ascertained that 5-HMF bound to ctDNA through groove binding, and it tended to bind to guanine–cytosine rich region of ctDNA which was characterized using Fourier transform infrared spectra and molecular docking. Circular dichroism spectral analysis and DNA cleavage assays indicated that the ctDNA conformation was altered from B to A form and 5-HMF caused DNA damage at higher concentration. CONCLUSIONS The results suggested that 5-HMF bound to ctDNA through groove binding and caused DNA damage. This research may contribute to understand the binding mechanism of 5-HMF to ctDNA and to the assessment of the toxicological effect of 5-HMF in biological processes. © 2018 Society of Chemical Industry
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CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Zhi-Hui Huang,Zhi-Yong Ji,Ying-Ying Zhao,Jie Liu,Fei Li,Jun-Sheng Yuan
Both thermal and alkali are effective means of persulfate (PS) activation, and the synergistic effect of them should achieve a great degradation result. It is evaluated for treating coal chemistry industry wastewater because the by-product produced in the process is sulfate, which is pre-existing in the wastewater. With thermal and alkali synergistic activation, the application of the response surface method revealed the effects of temperature, pH and concentration of persulfate on the degradation ratio of 2-methoxyphenol (MOP, a typical contaminant in coal chemical industry wastewater) and their interactions. The results showed that the degradation rate of the contaminant was temperature and pH dependent, while chloride (Cl − ) and sulfate (SO 4 2− ) ions had no obvious negative effect. The degradation ratio could be enhanced with higher activation temperature and pH (7–12). The faster degradation could be achieved by thermal-alkali synergistic activation, and the degradation ratio of 88.4% and 93.8% could be achieved at pH = 12 within 10 min and 20 min, respectively. Electron spin resonance (ESR) spectra and free radical scavenging experiments indicated that MOP degradation was achieved by the oxidation of both sulfate radical (SO 4 − ) and hydroxyl radical ( OH) at pH = 6, and only by OH at pH = 12. In addition, the radical reaction was intense under thermal-alkali synergistic activation of PS, while the quenching reaction was ineffective.
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FERROELECTRICS
·
2019
·
IF 0.697
Yan Ming,Hao Hu,Yao Chen,Zhao-Qian Li,You-Qing Shen,Hai-Lin Cong,Bing Yu
We reported a new method for preparing coated capillaries in this paper. First, we combined hydroxypropyl cellulose (HPC) and 2-Methacryloyloxyethyl phosphorylcholine (MPC) to form hydroxypropyl cellulose-poly (2-Methacryloyloxyethyl phosphorylcholine) (HPC-PMPC) by atom transfer radical polymerization (ATRP). Then the photosensitive polymer diazoresin (DR) was used as a linker to the inner wall of the capillary, and finally exposed to ultraviolet light to form a stable covalent bond coating. Protein adsorption on the inner surface of capillary was effectively inhibited. The cytochrome c (Cyt-c), lysozyme (Lys), ribonuclease A (RNase A) and bovine serum albumin (BSA) were separated obviously using capillary electrophoresis (CE) within 15 minutes and showed good stability and repeatability.
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ENVIRONMENTAL TOXICOLOGY
·
2019
·Vol. 34
·期 5
·666-673
·
IF 2.649
Xia Wang,Chenqian Zhou,Bingnan He,Baida Kong,Lai Wei,Rong Wang,Jiajia Lin,Yiyan Shao,Jianbo Zhu,Yuanxiang Jin,Zhengwei Fu
Fluorotelomer alcohols (FTOHs) are fluorinated intermediates used in manufacturing specialty polymer and surfactants, with 8:2 FTOH the homologue of largest production. FTOHs were found to pose acute toxicity, hepatotoxicity, nephrotoxicity, developmental toxicity and endocrine-disrupting risks, whereas research regarding immunotoxicity and its underlying mechanism, especially on specific immune cells is limited. Here, we investigated the immunotoxicity of 8:2 FTOH on immature immune cells in an in vitro system. We observed that exposure of HL-60 cells, a human promyelocytic leukemic cell line, to 8:2 FTOH reduced cell viability in a dose- and time-dependent manner. In addition, 8:2 FTOH exposure caused G1 cell cycle arrest in HL-60 cells, while it showed no effect on apoptosis. Exposure to 8:2 FTOH inhibited the mRNA expression of cell cycle-related genes, including CCNA1 , CCNA2 , CCND1 , and CCNE2 . Moreover, exposure to 8:2 FTOH inhibited the mRNA expression of granulocytic differentiation-related genes of CD11b , CSF3R , PU.1 , and C/EPBε in HL-60 cells . Furthermore, 8:2 FTOH exhibited no effect on intracellular ROS level, while hydralazine hydrochloride (Hyd), one reactive carbonyl species (RCS) scavenger, partially blocked 8:2 FTOH-caused cytotoxicity in HL-60 cells. Overall, the results obtained in the study show that 8:2 FTOH poses immunotoxicity in immature immune cells and RCS may partially underline its mechanism.
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Green Energy & Environment
·
2019
·
IF 0
Xiaolan Deng,Yuqi Jiang,Zengxi Wei,Minglei Mao,Ramyakrishna Pothu,Hongxia Wang,Caiyun Wang,Jinping Liu,Jianmin Ma
Increasing the energy density, power density as well as widening the operation voltage are essential to electrochemical capacitors to meet the practical energy demands. Herein, a novel flexible quasi-solid-state dual-ion asymmetric supercapacitor (ASC) with Ni(OH) 2 and Nb 2 O 5 nanosheets directly grown on stainless steel mesh is developed. In the dual-ion ASC, Nb 2 O 5 negative and Ni(OH) 2 positive electrodes react with Li + and OH − respectively in alkaline gel electrolyte to store energy, which is quite different from conventional alkali metal ion SCs and alkaline SCs. The as-assembled flexible device has an extended working voltage of 1.7 V and delivers a capacity of 5.37 mAh cm −2 , a maximum energy density and power density of 0.52 mWh cm −3 and 170 mW cm −3 , respectively. The device maintains around 60% capacity retention after long cycling up to 1000 cycles. Moreover, our device can light up a LED light efficiently upon fast charging. The proposed quasi-solid-state dual-ion ASC has potential applications in future portable electronics and flexible energy storage devices.
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BIOCATALYSIS AND BIOTRANSFORMATION
·
2019
·
IF 1.627
Lu Dong,Yongkai Xu,Yun Zhang,Aijun Sun,Yunfeng Hu
Chiral 1-phenylethanol and its ester derivative are important chiral chemicals in diverse industries and the preparation of those optically pure enantiomers is of great importance. One bacterium, Bacillus sp. DL-2, whose extracellular proteases could efficiently asymmetrically hydrolyse (±)-1-phenylethyl acetate, was isolated from the deep sea of the Western Pacific. After the immobilization of extracellular proteases and the optimization of enzymatic reactions, (R)-1-phenylethanol was prepared with the enantiomeric excess (e.e.) being 97% and the yield being 41%, respectively. The optimal resolution reaction condition for the preparation of (R)-1-phenylethanol using immobilized extracellular proteases was found to be 5-mM (±)-1-phenylethyl acetate, 360 mg/mL immobilized extracellular proteases, pH 6.5, and 20 °C for 2 h. (S)-1-phenylethyl acetate was generated through enzymatic kinetic resolution with the e.e. being as high as 99% and the yield being 71%, respectively. The optimal resolution reaction condition for the preparation of (S)-1-phenylethyl acetate was found to be 2.5-mM (±)-1-phenylethyl acetate, 440 mg/mL immobilized extracellular proteases, pH 7.5, and 35 °C for 10 h. Our report is the first report about the kinetic resolution of (±)-1-phenylethyl acetate using proteases and the enantio-preference of the proteases was found to be the same as those of most other esterases/lipases. Also notably, the optical purity of (S)-1-phenylethyl acetate generated through kinetic resolution using the proteases of Bacillus sp. DL-2 was the highest report so far. Proteases from deep-sea Bacillus sp. DL-2 are new contributions to the biocatalyst library for the preparation of valuable chiral alcohols and chiral esters through kinetic resolution.
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PROCESS BIOCHEMISTRY
·
2019
·
IF 2.883
Xinyun Xu,Jiahao Wang,Ting Yu,Haohan Nian,Hui Zhang,Guangli Wang,Feng Li
Aryloxyphenoxypropionate (AOPP) herbicides with a chiral center are widely used to selectively remove annual and perennial grasses. However, the study of the enzymes involved in enantioselective degradation of AOPP herbicides is limited. A novel family VIII carboxylesterase gene, estwx , hydrolyzed the ester bond cleavage of AOPP herbicides to form the corresponding acid and alkyl side chain alcohol, was cloned from Brevundimonas sp. strain QPT-2 and overexpressed in E. coli BL21. The purified recombinant EstWX was shown to hydrolyze a wide range of AOPP herbicides with various catalytic efficiencies. The enantioselectivity assay indicated that EstWX preferentially catalyzed the hydrolysis of the R -enantiomer of AOPP herbicides. The S73, K76, Y196 together with W368 residues, especially S73 and Y196, were essential for the catalytic function of the carboxylesterase. EstWX is a promising candidate for the bioremediation of multiple AOPP herbicide-contaminated environments and for future mechanism studies on the enantioselective degradation of chiral AOPP herbicides.
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