CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Xin Liu,Qi Fu,Peng Xu,Pengfei Zhu,Zhuoyu Yang,John C. Crittenden
A sensitive spectrophotometric method (the Br − -ABTS method) for measuring monopersulfate (PMS) of 0–20 μM in water was established. The Br − -ABTS method was based on the oxidation coloration reaction where Br − as catalyst promoted PMS for oxidation of ABTS forming the green-colored ABTS radical (ABTS • + ) under pH 3.0 (50 mM phosphate buffer). ABTS • + could be quantitatively measured at 415 nm, 650 nm, 732 nm and 820 nm using UV–vis spectrophotometer. There was a well linear relationship between the absorbance of ABTS • + and PMS concentration with the value of R 2 being 0.999. The proposed Br − -ABTS method was highly sensitive, and the absorbance generated by Br − -ABTS at 415 nm was 6.59 × 10 4 cm −1 per M (mol L –1 ) of PMS. The changes of pH from 3.0 to 9.0 had an insignificant effect on the calibration curve of Br − -ABTS method. The reaction of PMS with ABTS had a stoichiometric coefficient of 1:1.96 at the pH 3.0. The residual absorbance of ABTS •+ in ultrapure water, Xiangjiang water and Hou-lake water was stable within 30 min. Moreover, the trace PMS concentration of 0.03–20 μM in ultrapure water, 0.05–20 μM in natural water (e. g. Xiangjiang water and Hou-lake water) and 1–20 μM in wastewater was accurately measured with the proposed Br − -ABTS method. Additionally, the interference of natural water matrix (e. g. humic acid), metal ions (e. g. Co(II), Fe(III) and Cu(II)) and hydroxylamine had barely interference for the proposed Br − -ABTS method. Furthermore, the Br − -ABTS method was more accurate and flexible to determine PMS concentration than DPD method during the decolorization of rhodamine B in the Co(II)/PMS system, Cu(II)/PMS system and hydroxylamine/Fe(III)/PMS process.
研究领域:
环境科学
·
分析化学
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APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2026
·
IF 3.5
Zhou Jianguo,Jiang Yanjun,He Ying,Ma Li,Yue Xiaoyang,Zhou Liya,Liu Guanhua,Zheng Xiaobing
Nucleoside analogues play a crucial role in antiviral and anticancer drug synthesis. Owing to their high catalytic efficiency and substrate specificity, nucleoside 2′-deoxyribosyltransferases (NDTs) emerge as promising biocatalysts for nucleoside analogue synthesis. However, wild-type NDTs suffer from low yields in synthesizing halogen-substituted 2′-deoxypyrimidine nucleosides due to steric hindrance from halogen substituents in the active pocket and competitive product hydrolysis. Herein we identify an NDT from Bacillus haynesii ( Bh NDT) via sequence screening and introduce an E56T/D60A ( Bh NDT-M2) double mutation to disrupt the salt bridges and increase structural flexibility, thereby widening the active pocket and enhancing catalytic activity. The Bh NDT-M2 mutant displays markedly improved activity and efficiency for synthesizing 5-fluoro-2′-deoxyuridine (FdUrd), achieving 62% of yield under 20 mM substrate, which is twice that of the wild-type. In addition, we find that high substrate concentration can bring an unexpected inhibitory effect on hydrolytic side reactions, which further improve the catalytic performance of Bh NDT-M2, achieving a 55% yield of under 150 mM substrate. The Bh NDT-M2 also exhibits high substrate specificity toward a range of 2′-deoxypyrimidine nucleoside analogues. To facilitate practical applications, Bh NDT-M2 is immobilized onto an amino-functionalized resin, and the resulting immobilized enzyme shows excellent reusability, with only 20% loss of activity after eight cycles. Collectively, these properties establish Bh NDT-M2 as a promising biocatalyst and lay the foundation for large-scale nucleoside analogue synthesis. Graphical The alternative text for this image may have been generated using AI.
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POLYMER TESTING
·
2022
·
IF 4.931
Yuezhou Liu,Yanjing Liu,Xiyue Li,Yongfang Qian,Lihua Lv,Ying Wang
In order to fabricate antibacterial nanofiber membranes for tissue engineering field, the oxidative damage of magnesium hydroxide nanoparticles (Mg(OH) 2 NPs) against the model system of Escherichia coli ( E. coli ) was researched by measuring the oxidative stress response, oxidative stress products and glucose metabolism. The toxicity of Mg(OH) 2 NPs to a normal biological system was evaluated in vivo through the acute oral toxicity, blood physiological and serum biochemical markers and acute skin irritation, indicating that the Mg(OH) 2 NPs exhibited great biosafety. The Mg(OH) 2 NPs with antibacterial property and biosafety were loaded on PCL/PVP nanofiber substrates through electrospinning technology to fabricate the Mg(OH) 2 /PCL/PVP nanofiber membranes. The results of characterization and antibacterial test showed that the Mg(OH) 2 /PCL/PVP nanofiber membranes with 8.0 wt% Mg(OH) 2 NPs present excellent antibacterial rate of 100% against E. coli that the Mg(OH) 2 NPs can be physically and evenly loaded on nanofiber substrates.
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Frontiers in Chemistry
·
2022
·
IF 5.545
Li-Na Ke,Ling-Qi Kong,Xiu-Lian Zhu,Feng-Xu Wu,Qin-Hua Chen,Bin Li,Yun Dong,Hong-Mei Wang,Xiao-Hua Zeng
We have synthesized Rhopaladins’ analog (2E,4E)-4-chlorobenzylidene-2-(4-chlorostyryl)-N-cyclohexyl-1-(4-fluorophenyl)-5-oxopyrrolidine-2-carboxamide (RPDPRH) via a highly facile, inexpensive and green approach and verified the structural superiority of compound RPDPRH through molecular docking. Moreover, we further detected the anti-proliferation, apoptosis and HPV E6/E7 effects of RPDPRH on CaSki cells. Finally, we confirmed that compared with the previous compound (E)-N-(tert-butyl)-2-(4-chlorobenzoyl)-4-(4-fluorobenzylidene)-1-isopropyl-5-oxopyrrolidine-2-carboxamide (RPDPB), RPDPRH could better inhibit proliferation, induce apoptosis, and down-regulate HPV E6/E7 mRNA expression on Caski cells. And preliminary RT-PCR experiments have demonstrated that RPDPRH also could affect the expression of Bcl-2, Bax and Caspase-3 mRNA in Caski cells. In summary, RPDPRH has potential as an effective agent against cervical cancer and will play an important role in our subsequent research.Keywords: 4-arylidene-5-oxopyrrolidine, green synthesis, molecular docking, anti-tumor activity, apoptosis
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ACTA PHARMACOLOGICA SINICA
·
2021
·Vol. 43
·期 7
·1749-1757
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IF 6.15
Li Dan,Ding Jin,Liu Te-li,Wang Feng,Meng Xiang-xi,Liu Song,Yang Zhi,Zhu Hua
The spike protein of SARS-CoV-2 interacts with angiotensin-converting enzyme 2 (ACE2) of human respiratory epithelial cells, which leads to infection. Furthermore, low-dose radiation has been found to reduce inflammation and aid the curing of COVID-19. The receptor binding domain (RBD), a recombinant spike protein with a His tag at the C-terminus, binds to ACE2 in human body. We thus constructed a radioiodinated RBD as a molecule-targeted probe to non-invasively explore ACE2 expression in vivo, and to investigate radiotherapy pathway for inhibiting ACE2. RBD was labeled with [ 124 I]NaI using an N-bromosuccinimide (NBS)-mediated method, and 124 I-RBD was obtained after purification with a specific activity of 28.9 GBq/nmol. Its radiochemical purity was (RCP) over 90% in saline for 5 days. The dissociation constant of 124 I-RBD binding to hACE2 was 75.7 nM. The uptake of 124 I-RBD by HeLa ACE+ cells at 2 h was 2.96% ± 0.35%, which could be substantially blocked by an excessive amount of RBD, and drop to 1.71% ± 0.23%. In BALB/c mice, the biodistribution of 124 I-RBD after intravenous injection showed a moderate metabolism rate, and its 24 h-post injection (p.i.) organ distribution was similar to the expression profile in body. Micro-PET imaging of mice after intrapulmonary injection showed high uptake of lung at 1, 4, 24 h p.i.. In conclusion, the experimental results demonstrate the potential of 124 I-RBD as a novel targeted molecular probe for COVID-19. This probe may be used for non-invasive ACE2 mapping in mammals.
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ACS Omega
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2020
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IF 2.87
Yanan Zhang,Dajun Hou,Bingshan Zhao,Chunyin Li,Xiaoyan Wang,Lanying Xu,Tao Long
A ratiometric DNA sensor was developed based on fluorescent silicon nanodots (SiNDs) and Ru(bpy)2(dppx)2+. The absorption spectrum of Ru(bpy)2(dppx)2+ has significant overlap with both the excitation and emission spectra of SiNDs. Therefore, fluorescence quenching of Ru(bpy)2(dppx)2+ toward SiNDs can occur on account of the strong inner filter effect. The effect of quenching is not influenced by the specific binding between Ru(bpy)2(dppx)2+ and DNA. Fluorescence turn-on detection of DNA can be performed employing Ru(bpy)2(dppx)2+ and SiNDs as the response and reference signals, respectively. Using SiND–Ru(bpy)2(dppx)2+, a convenient, sensitive, rapid, and precise method could be developed for DNA detection. In aqueous solutions, the I601/I448 fluorescence intensity ratio of SiND–Ru(bpy)2(dppx)2+ increases linearly in the DNA concentration range of 20–1500 nM. The limit of detection and precision of the method is 4.3 nM and 3.5% (50 nM, n = 13), respectively. The ratiometric sensor was tested for visual detection of trace DNA. Moreover, this method was found suitable for the ratiometric detection of DNA in a simulated sample and a human serum sample, and the recoveries were in the range of 98–119%.
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2020
·
IF 2.888
Pan Zhang,Mengying Li,Chunjie Lv,Yanjie Zhang,Lemeng Wang,Dong Fu
Piperazine (PZ) was used to enhance the absorption of CO 2 in 2-diethylaminoethanol (DEAE) and 1-dimethylamino-2-propanol (DMA2P) aqueous solutions. The mole fraction of CO 2 in N 2 -balanced gas mixtures ranged from 0.1 to 0.8. The mass fractions of amine and PZ ranged from 0.300 to 0.500 and from 0.050 to 0.075, respectively. The experiments were performed at 313.2 K. The absorption capacity and absorption rate under a series of conditions were illustrated, and the effect of CO 2 partial pressure on the absorption performance was demonstrated. At a given CO 2 partial pressure, the CO 2 absorbed by the PZ promoted DEAE and DMA2P aqueous solutions increases with the mass fraction of the mixed aqueous solutions, and it increases with the CO 2 partial pressure at a given mass fraction. The absorption capacity of the DMA2P-PZ aqueous solution is slightly higher than that of the DEAE-PZ aqueous solution. In addition, the absorption rate depends on the competitive effects of the mass fractions, solution viscosity and the partial pressure of CO 2 .
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Weiwei Yang,Mao Peng,Ye Lv,Mengya Sun,Jinli Zhang,Wei Li,Yan Fu
2-Hydroxybenzaldehyde (SALD) exhibits special reactivity in various chemical reactions due to the existence of aldehyde and hydroxyl groups, which also make it a challenge to achieve high conversion and selectivity for SALD production. Herein, β-Ni(OH) 2 nanosheets over nickel foam (NF) at different hydrothermal temperatures were synthesized for electrocatalytic oxidation (ECO) of 2-hydroxybenzyl alcohol (SAL) into SALD. The β-Ni(OH) 2 electrode obtained at 160 °C achieves the best ECO performance in 2.5 M KOH at the applied potential of 1.45 V (RHE), showing the SALD selectivity of 78.90% and the Faradaic efficiency of 87.94% at the SAL conversion of 69.76%. ECO of SAL reduces the cell voltage and boosts the hydrogen productivity by 2.74 times. It is of great importance to find that potential-driven surface reconstruction of β-Ni(OH) 2 enables selective conversion of SAL into SALD. Side reactions including OER as well as oxidation of phenolic group can be effectively controlled via regulating applied potentials on β-Ni(OH) 2 . This work is the first report on direct electrochemical oxidation of SAL with high SALD selectivity, and offers a green and clean strategy for highly selective production of SALD under mild conditions.
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ACS Applied Materials & Interfaces
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2023
·
IF 9.5
Wenjie Chen,Li Xie,Can Lv,Erqun Song,Xiaokang Zhu,Yang Song
Ferroptosis, an iron-dependent cell death driven by the lethal levels of lipid peroxidation (LPO), becomes a promising anticancer strategy. However, the anticancer efficacy of ferroptosis is often hindered by the activation of nuclear factor erythrocyte 2-associated factor 2 (Nrf2), which is an indispensable regulator of the cellular antioxidant balance by preventing the accumulation of intracellular reactive oxygen species (ROS). Herein, we present a rational design of a Tf-targeted cascade nanoplatform TPM@AM based on mesoporous polydopamine (MPDA) co-encapsulating a ferroptosis inducer (artesunate, ART) and an Nrf2-specific inhibitor (ML385) to enhance intracellular ROS and therefore amplify ferrotherapy. Transferrin (Tf) can specifically recognize the transferrin receptor (TfR) on the surface of the cell membrane, which binds and transports iron into cells. When TPM@AM is endocytosed, the high-acid tumor microenvironment and laser irradiation trigger the collapse of MPDA to release ART and ML385. Furthermore, MPDA endows the nanoplatform with photothermal capability. The nanoplatform exhibits high efficiency for synergistic tumor suppression, representing a spatiotemporal controllable therapeutic strategy for precise synergistic cancer therapy.
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EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY
·
2019
·Vol. 121
·期 7
·1900040
·
IF 1.852
Lukai Ma,Guoqin Liu,Xinqi Liu
The formation of three toxic reactive aldehydes, malondialdehyde (MDA), 4-hydroxy-hexenal (HHE), and 4-hydroxy-2-nonenal (HNE), is investigated in five commonly consumed vegetable oils using a method based on the Schaal oven test. HHE is only detected in linseed oil (LO) and rapeseed oil (RO), while MDA and HNE are found to be present in all tested oils. The formation potential of MDA, HHE, and HNE in the tested oils is closely related to the initial polyunsaturated fatty acid (PUFA) content in the oil. Correlation analyses reveal low correlation coefficients for MDA, determining its unsuitability to evaluate the oxidation of oils with low PUFA content, such as palm oil and camellia oil; in contrast, HHE and HNE show sufficient correlations with other oxidation indices in all tested oils. Furthermore, regression analysis indicates that HHE content can predict the oxidation of ω-3 type oil, while HNE content can estimate oxidative deterioration of ω-6 type oils. Particularly, HNE content can also evaluate the oxidation of ω-9 type oils such as PO and CLO with relatively low PUFA level for the high correlations (>0.991, P < 0.01) toward the total oxidation value (TOTOX). Practical Applications : Edible oil consumption continues to increase worldwide. Therefore, it is very important to understand the conditions under which potentially health-damaging compounds are formed in these oils and to develop methods to inhibit their formation or eliminate them from the oils. This study investigates the formation of three toxically reactive aldehydes, namely MDA, HHE, and HNE, through lipid oxidation, specifically PUFA peroxidation. The application of these aldehydes as oxidation indicators for different vegetable oils is also explored. This work could prove beneficial for the quality control of vegetable oils in the edible oil industry. The formation of three toxic aldehydes, MDA, HHE, and HNE in different types of vegetable oils is investigated. Considerable amounts of MDA, HHE, and HNE is found in all the tested oils. The results show the formation of these three aldehydes is competitive. Besides, MDA content is not appropriate to evaluate the oxidation of oils with low PUFA content, such as PO and CLO; while HHE and HNE can characteristically depict the oxidation of ω-3 and ω-6 type oil.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2018
·
IF 2.829
Shaoling Bai,Yaqi Wang,Bin Liu,Yujie Zhu,Ruiwei Guo
Dispersion copolymerization of acrylamide (AM) and sodium 2-acrylamido-2-methylpropanesulfonate (AMPSNa) in aqueous ammonium sulfate (AS) solution was performed without mechanical stirring using a macro-RAFT agent sodium poly(2-acrylamido-2-methylpropanesulfonate) trithiocarbonate (PAMPSNa-TTC) as the stabilizer and 2,2′-azobis(2-methylpropionamide) dihydrochloride as the initiator. The effects of various polymerization parameters were systematically investigated regarding dispersion stability, particle size, molecular weight and apparent viscosity. A new mechanism for particle formation and the particle stability of aqueous dispersion polymerization was proposed.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2018
·
IF 2.441
Yilin Sun,Le Zhen,Ying Peng,Jiankun Wang,Fei Fei,Lixiang Aa,Wenjiao Jiang,Xue Pei,Li Lu,Jie Liu,Guangji Wang,Kun Hao
To improve bioavailability and provide resistance to deamination , an array of gemcitabine (dFdC) prodrugs carrying the acyl modifications has been successful in the optimization of pharmacokinetic properties of dFdC, but the reports about 4- N -carbobenzoxy-dFdC (Cbz-dFdC), a dFdC prodrug bearing alkyloxycarbonyl modification, are relatively rare. Notably, in vivo enzymatic hydrolysis was an absolutely essential factor for the activation of these prodrugs, which is correlated with the anti-tumor activity. Therefore, detailed metabolism studies of Cbz-dFdC should be carried out for a more authentic pharmacodynamic evaluation. In order to detect the pharmacokinetic characteristics of Cbz-dFdC, a selective, sensitive and accurate method for the simultaneous determination of Cbz-dFdC, along with dFdC and its major metabolite dFdU in rat plasma was developed and validated using UFLC–MS/MS techniques. Column was at 40 °C for separation using an eluent with acetonitrile and 0.1% formic acid , 1 mM ammonium formate at a flow rate of 0.2 mL/min. Detection was performed using ESI source in positive ion selected reaction monitoring mode by monitoring the following ion transitions m / z 398.1 → 202.2 (Cbz-dFdC), m / z 264.1 → 112.0 (dFdC), m / z 265.3 → 113.2 (dFdU) and m / z 246.1 → 112.0 (IS). Analytes were extracted by simple precipitation with acetonitrile containing internal standards followed by liquid-liquid extraction with ethyl acetate . The calibration curves of Cbz-dFdC, dFdC and dFdU were linear in the concentration range of 2 to 500 ng/mL, 2 to 500 ng/mL and 40 to 10,000 ng/mL, respectively. The assay ranges selected for the three analytes were appropriate and minimized the need for reanalysis. All the validation data, such as intra- and inter-day precision, accuracy, selectivity and stability, were within the required limits. In conclusion, the sensitive analytical assay was selective and accurate for the determination of rat plasma concentrations of Cbz-dFdC, dFdC and dFdU from a single LC–MS/MS analysis and well-suited to support pharmacokinetic studies.
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