Reaction Kinetics Mechanisms and Catalysis
·
2013
·Vol. 110
·期 1
·31-39
·
IF 1.104
Zhang Tiantian,Zhang Xiaoli,Li Hongya,Bai Weili,Zhao Binxia
Anhydrous ethanol and choline hydroxide, which are friendlier to human beings, were applied in the process for preparing l -α-glycerophosphocholine. The mechanism of the ethanolysis of phosphatidylcholine catalyzed by choline hydroxide was proposed, the kinetics of the transesterification was evaluated under the catalyst concentration range of 0.006–0.018 mol/L and the temperature range of 293.15–323.15 K. The experimental data were well described by the pseudo-first order equation. The effects of nucleophilic reagent, concentration of catalyst, ethanol-to-oil molar ratios and the temperature were investigated, and the calculated activation energy was 24.28 kJ/mol.
研究领域:
生物化学
·
食品科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Yanjie Xu,Hui Chen,Xuefeng Liu,Lianlian Sun,Yinjun Fang
Long-chain alkanoylcholines (LCAC) are potential candidates to limit viruses’ transmission and suitable substrates of butyrylcholinesterase (BChE) to be hydrolyzed. Thus, BChE-catalyzed LCAC hydrolysis is expected to be a safer and greener demulsification strategy in demulsifying LCAC-based emulsions and/or microemulsions . Myristoylcholine bromide (MCB)-based oil-in-water (O/W) emulsions with different oils, from hydrocarbon nonpolar oil (octane and D80) to ester-containing polar oil (jojoba oil and edible oil) as well as the complex oily mixture (crude oil), were constructed. MCB-based microemulsions were constructed by pseudo-ternary phase diagram method. The BChE-catalyzed hydrolysis of MCB was monitored by using of two-phase titration. MCB-based O/W type emulsions and microemulsion can be actively demulsified by using of BChE under mild conditions of pH = 7.4 and 37 °C. No lethal adverse effect of the oil type on the BChE-catalyzed hydrolysis of MCB was observed in demulsifying emulsions. BChE can be reused and presented an excellent reusability over five times of recycling, clarifying a promising prospect of this enzymatic demulsification strategy in the treatment of LCAC-emulsified wastewater.
研究领域:
生物化学
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环境科学
·
医学
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHIC SCIENCE
·
2021
·Vol. 59
·期 5
·405-411
·
IF 1.618
Decheng Suo,Xia Fan,Shulin Wei,Yang Li
A simple and sensitive method was proposed for choline, carnitine, acetylcarnitine (ACa) and acetylcholine (ACh) separation in feed, blood and urine of animals by using ion chromatography (IC) and detection by tandem mass spectrometry (MS/MS). Analytes were extracted using a mixture of acetonitrile and water, purified by C18 solid-phase extraction columns, separated via IC with an IonPac SCS-1 column and detected by an MS/MS detector by using isotopic internal standards for quantification. The effects of different chromatographic parameters on the separation were also investigated. Under optimal conditions, the recovery was >90%, with the relative standard deviations of <15%. The proposed method was highly reliable for the simultaneous determination of choline, carnitine, ACa and ACh in feed, blood and urine.
研究领域:
分析化学
·
动物营养学
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生物化学
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DOI
PubMed
高影响因子
Journal of Functional Foods
·
2020
·
IF 3.701
Xiaomeng Xu,Rong Liang,Dongmei Li,Chengyao Jiang,Songyi Lin
To investigate the dose-effect relationship of sea cucumber peptides on memory function improvement, animal experiments, behavioral experiments, ACh content, AChE activity, hippocampal morphology, and protein modifications were detected. Sea cucumber peptides (650 mg/kg, 1300 mg/kg, 2600 mg/kg body weight) and piracetam (400 mg/kg) were gavaged into the mice. Scopolamine (5 mg/kg) were administered intraperitoneally to mice. In behavioral experiments, the escape latency and the shocked time of sea cucumber peptides (SCP) groups were significantly reduced ( P < 0.05). Determination of biochemical indicators found that ACh content and AChE activity of SCP groups were increased ( P < 0.05). The number of neurons in the hippocampus of SCP groups were larger, arranged neatly and intact. The histone acetyltransferases activity of SCP groups may be lower than that of the Scopolamine group, so the acetylation level is down-regulated and approached to dynamic equilibrium, thereby the memory activity of mice was improved.
研究领域:
神经科学
·
药理学
·
分子生物学
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产品关联
DOI
高影响因子
Journal of Functional Foods
·
2020
·
IF 3.701
Zhijie Bao,Penglin Zhang,Jin Chen,Jie Gao,Songyi Lin,Na Sun
This study was conducted to investigate possible mechanisms underlying egg yolk phospholipids on improving memory using scopolamine–treated mice and PC12 cells. Oral administration of egg yolk phospholipids significantly decreased latency in passageway water maze tasks and reduced error hits in passive avoidance tests for scopolamine–treated mice ( P < 0.05). As the results presented, egg yolk phospholipids attenuated spatial memory deficits via preventing region–specific lesions in hippocampus CA1-2 and regulating the activity of cholinergic biomarkers. Egg yolk phospholipids significantly inhibited scopolamine–induced increase of acetylcholinesterase activity and decrease of choline acetyltransferase activity ( P < 0.05), thus maintaining the release of acetylcholine at a normal level. Further analysis showed that egg yolk phospholipids downregulated scopolamine–induced MAO activity and MDA level in PC12 cells ( P < 0.05). These data suggest that egg yolk phospholipids might exert neuroprotective effects via attenuating cholinergic damage and inhibiting the oxidative stress in vitro .
研究领域:
神经科学
·
药理学
·
营养科学
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2022
·
IF 9.221
Yumei Zhang,Liyun Ding,Haowen Zhang,Pan Wang,Haijun Li
Acetylcholine (Ach) is an important neurotransmitter and plays a vital role in the diagnosis and treatment of many neurological diseases. A new acetylcholine optical fiber biosensor is reported based on the nitrogen doped fluorescent carbon quantum dots/ acetylcholinesterase (N-CQDs/AchE) compound, where AchE was immobilized on the surface of N-CQDs by the cross-linking method. N-CQDs were synthesized by the hydrothermal method as fluorescent probe and can be responsible for pH value. The optical properties , morphology, particle size distribution and surface groups of N-CQDs were characterized by UV-Vis spectrophotometer, Fluorescence spectrometer, High-resolution transmission electron microscope (TEM) and Fourier transform infrared spectrometer (FTIR), respectively. The relationship between acetylcholine chloride solution and fluorescence intensity of N-CQDs/AchE complex was detected in detailed. Good linear relationship between fluorescence intensity and the concentration of acetylcholine from 20–200 µM and 1–100 nM with the lower detection limits of 16.28 µM and 0.29 nM, respectively. Compared with other sensors, this new optic fiber sensor immobilized (N-CQDs/AchE) complex is more simple and operable.
研究领域:
生物医学工程
·
神经科学
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DOI
高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Jiaxin Wang,Xuening Lu,Jiaen Zhang,Zeheng Xiao
Lipids such as phosphatidylcholine (PC), 3- sn -phosphatidylethanolamine (PE), sphingomyelin (SM) and L-α-lysophosphatidylcholine (LPC) are the major components of biological membranes and play important roles in physiological functions. Here, PC, PE, SM, and LPC were extracted from golden apple snails (GAS, Pomacea canaliculata ) and GAS flesh (GASF) using an ethanol/hexane sequential scheme and quantified simultaneously using ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS) to evaluate whether the GAS could be the source of the four lipids. Our results suggest that ethanol extracts contained the most crude lipids, and the yield of dry (evaporated) lipids were 3.45 g per 100 g fresh GASF and 1.82 g per 100 g of fresh GAS. Quantification of the lipids using UHPLC-ESI-MS/MS suggested that GAS contained PE, PC, SM and LPC, with SM being the most abundant lipid (after purification: 1.71 and 1.42 mg g −1 dry weight from 100 g of GASF and GAS, respectively). The method we used is cost-effective, and the recovery rates of ethanol and hexane ranged from 80−91% and 87−91% respectively. Overall, GAS and GASF are potential raw materials for lipids such as SM and PC extraction using the ethanol/hexane method. Comparatively, lipids extraction from the GAS is more effective and timesaving. Our finding would provide a way to utilize GAS and potentially control its invasion.
研究领域:
生物化学
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分析化学
·
入侵生物学
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DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2014
·
IF 6.451
Shao-Bin He,Gang-Wei Wu,Hao-Hua Deng,Ai-Lin Liu,Xin-Hua Lin,Xing-Hua Xia,Wei Chen
Platinum nanoparticles (PtNPs) in the scaffold of bovine serum albumin (BSA) through biomineralization are found to possess excellent peroxidase-like activity that can catalyze N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium salt (TOPS) coupled with 4-amino-antipyrine (4-AAP) by the action of hydrogen peroxide to give an obvious purple product. Based on this phenomenon, acetylcholinesterase (AChE) and choline oxidase (ChOx) are used to catalyze ACh and choline to form the active product H 2 O 2 and the as-produced H 2 O 2 is detected optically. Owning to the protection effect of the protein shell, BSA–PtNPs turn out to be very stable and preserve the catalytic activity in the presence of protein and even in the real plasma samples. This protein antifouling property makes the BSA–PtNPs suitable for a wide range of applications in sensors for biological samples. Choline in infant formula and ACh in plasma have been successfully detected.
研究领域:
生物化学
·
医学检测
·
纳米材料科学
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DOI
高影响因子
ANALYST
·
2020
·Vol. 145
·期 15
·5206-5212
·
IF 3.978
Tianzi Li,Yetong Gao,Huiya Li,Chenyang Zhang,Yifei Xing,Meng Jiao,Yu-e Shi,Wei Li,Yongqing Zhai,Zhenguang Wang
Butyrylcholinesterase (BChE) activity is an important index for a variety of diseases. In this work, a “turn-on” assay is proposed based on controlling the inner filter effect (IFE) of MnO2 nanosheets (NSs) on sulfur nanodots (S-dots). The fluorescence of S-dots is effectively quenched by the MnO2 NSs, due to the wide overlap of the emission spectrum of S-dots and absorption spectrum of MnO2 NSs, together with the superior light absorption capability of MnO2 NSs. BChE can catalyze acetylthiocholine and produce thiocholine, which effectively decomposes the MnO2 NSs into Mn2+, resulting in the disappearance of the IFE and recovery of fluorescence of S-dots. Two-stage linear relationships between the ratio of fluorescence intensity and concentration of BChE are observed from 0.05 to 10 and from 10 to 500 U L−1. A limit of detection of 0.035 U L−1 is achieved, which is the best performance so far. The as-proposed assay is robust enough for practical detection in human serum, and it can avoid interference from its sister enzyme (acetylcholinesterase) and glutathione at the micromolar level. The presented results provide a clue for the functionalization of S-dots, and offer a powerful tool as an analytic technique for nanomedicine and environmental science.
研究领域:
分析化学
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纳米技术
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生物医学工程
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环境科学
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DOI
高影响因子
Methods and Applications in Fluorescence
·
2024
·Vol. 12
·期 2
·025003
·
IF 2.4
Conghuan Lin,Huizhi Du
Forsythoside E is one secondary metabolite of Forsythia suspensa (Thunb.) Vahl. In the study, the interactions between forsythoside E and two types of cholinesterases, acetylcholinesterase and butyrylcholinesterase were investigated in the different conditions. Forsythoside E increased the fluorescence intensity of acetylcholinesterase but quenched the fluorescence of butyrylcholinesterase. Aβ25-35 used in the study may not form complexes with cholinesterases, and did not affect the interaction between forsythoside E and cholinesterases. The charged quaternary group of AsCh interacted with the 'anionic' subsite in acetylcholinesterase, which did not affect the interaction between forsythoside E and acetylcholinesterase. The enhancement rate of forsythoside E to acetylcholinesterase fluorescence from high to low was acid solution (pH 6.4), neutral solution (pH 7.4) and alkaline solution (pH 8.0), while the reduction rate of forsythoside E to butyrylcholinesterase fluorescence was in reverse order. Metal ions may interact with cholinesterases, and increased the effects of forsythoside E to cholinesterases fluorescence, in order that Fe3+ was the highest, followed by Cu2+, and Mg2+. A forsythoside E-butyrylcholinesterase complex at stoichiometric ratio of 1:1 was spontaneously formed, and the static quenching was the main quenching mode in the process of forsythoside E binding with butyrylcholinesterase. The K values of two complexes were pretty much the same, suggesting that the interaction between cholinesterases and forsythoside E was almost unaffected by acid–base environment and metal ions. The n numbers of two cholinesterases approximately equaled to one, indicating that there was only one site on each cholinesterase applicable for forsythoside E to bind to.
研究领域:
生物化学
·
药理学
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产品关联
DOI
PubMed
高影响因子
Phytochemistry Letters
·
2020
·
IF 1.459
Yang Liu,Xiao-Chang Yao,Jing Li,Zhen-Xing Zou,Chen Xi,Kang-Ping Xu,Feng-Hua Kang,Ping-Sheng Xu,Gui-Shan Tan
Two new unsaturated fatty acid esters ( 1 and 2 ) and five new unsaturated fatty acids ( 4 – 8) , together with two known analogs ( 3 and 9 ) were isolated from the aerial parts of Lycopodiastrum casuarinoides. Their structures were unambiguously elucidated by obtaining extensive spectroscopic data and comparing them with data in the literature. The absolute configurations of 1 and 2 were established by a modified Mosher's method. All compounds were evaluated in vitro for their inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Compound 8 exhibited the most potent inhibitory activity against AChE with an IC 50 value of 1.16 ± 0.13 μM.
研究领域:
植物化学
·
药理学
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DOI
高影响因子
Journal of Materials Chemistry B
·
2017
·Vol. 5
·期 38
·7861-7865
·
IF 4.543
Yongxin Li,Shuhan Yin,Yan Lu,Huipeng Zhou,Hong Jiang,Niu Niu,Hui Huang,Ling Zhang,Kenneth Kam-Wing Lo,Cong Yu
A novel choline detection strategy is developed based on in situ polymerization of aniline on the surface of upconverting nanoparticles (UCNPs). In acidic buffer solution, aniline was protonated and attached to the surface of negatively charged UCNPs via electrostatic interactions. The in situ polymerization of aniline was initiated with the addition of a catalyst (HRP) and an oxidization agent (H2O2). The upconversion luminescence was efficiently quenched by polyaniline (PANI), and the quenching efficiency could reach 97.5%, which was higher than most of the reported organic quenchers for UCNPs. In the presence of choline oxidase, choline was hydrolyzed and produced H2O2, which caused production of polyaniline and quenching of upconversion luminescence. A sensing method for choline is thus developed. The upconversion luminescence based choline detection method can very much avoid the interference of fluorescent substances in biological samples, and also possesses the advantages of good selectivity, sensitivity and convenience.
研究领域:
分析化学
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纳米技术
·
生物传感器
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）