JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2019
·
IF 3.571
Md. Kamrul Hasan,Golam Jalal Ahammed,Shuchang Sun,Mengqi Li,Hanqin Yin,Jie Zhou
Sulfur (S) metabolism plays a vital role in Cd detoxification, but the collaboration between melatonin biosynthesis and S metabolism under Cd stress remains unaddressed. Using exogenous melatonin, melatonin-deficient tomato plants with a silenced caffeic acid O-methyltransferase (COMT) gene, and COMT-overexpressing plants with cosuppression of sulfate transporter (SUT)1 and SUT2 genes, we found that melatonin deficiency decreased S accumulation and aggravated Cd phytotoxicity, whereas exogenous melatonin or overexpression of COMT increased S uptake and assimilation, resulting in an improved plant growth and Cd tolerance. Melatonin deficiency promoted Cd translocation from root to shoot, but COMT overexpression caused the opposite effect. COMT overexpression failed to compensate the functional hierarchy of S when its uptake was inhibited by cosilencing of transporter SUT1 and SUT2. Our study provides genetic evidence that melatonin-mediated tolerance to Cd is closely associated with the efficient regulation of S metabolism, redox homeostasis, and Cd translocation in tomato plants.
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DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 7
·077508
·
IF 4.386
Chi Zhang,Yanli Ji,Yulong Zhang,Baoxian Ye,Lina Zou
In this work, a green and low-cost voltammetric sensor, poly(L-Ornithine) film modified glassy carbon electrode (PLO/GCE) was fabricated for the first time to detect thiamethoxam. The PLO/GCE was prepared by one-step electrodeposition, which is environmentally friendly, convenient and highly controllable. The modified electrode was characterized by electrochemical method, IR and SEM. Moreover, the redox character of thiamethoxam at proposed sensor was studied systematically. The PLO/GCE showed high sensitivity to thiamethoxam detection. Utilizing the linear sweep voltammetry, a wider linear range (5.0 × 10−8 mol l−1 −9.0 × 10−6 mol l−1) and lower detection limit (1.7 × 10−8 mol l−1) (S/N = 3) were achieved. In addition, the proposed method was successfully applied to the determination of thiamethoxam in pesticide.
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高影响因子
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
·
2020
·Vol. 56
·期 2
·999-1012
·
IF 2.773
Xiuyun Guo,Yawei Zhang,Muneer Ahmed Jamali,Zengqi Peng
Summary The present work examined the impact of L-Arginine (Arg) on the emulsifying properties, interfacial behaviour and conformational characteristics of myofibrillar proteins (MPs) at high (0.6 m ) and low (0.15 m ) salt concentration to maintain good emulsifying properties of MPs at low salt concentration. The data indicated that Arg increased the emulsifying activity index/emulsion stability index (EAI/ESI) and decreased the CI and droplet size of emulsions regardless of salt concentration. Raman spectra revealed that the α-helix content decreased from 60.30% to 51.26% at high salt concentration, and from 60.20% to 54.82% at low salt concentration in the presence of Arg. In addition, MPs treated with Arg exhibited a higher interfacial pressure and more rapidly diffusion to the oil surface. Meanwhile, Arg increased the interfacial protein loading. The results demonstrated that Arg caused the unfolding of MPs, promoting the adsorption of proteins and decreasing the interfacial tension, ultimately improving the stability of emulsions at low salt concentration.
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高影响因子
BIOMACROMOLECULES
·
2021
·
IF 6.988
Yu Zhang,Bo Xia,Yanyan Li,Xianfu Lin,Qi Wu
The synthesis of optically pure polymers is one of the most challenging tasks in polymer chemistry. Herein, Novozym 435 (Lipase B from Candida antarctica, immobilized on Lewatit VP OC 1600)-catalyzed polycondensation between d-/l-aspartic acid (Asp) diester and diols for the preparation of helical chiral polyesters was reported. Compared with d-Asp diesters, the fast-reacting l-Asp diesters easily reacted with diols to provide a series of chiral polyesters containing N-substitutional l-Asp repeating units. Besides amino acid configuration, N-substituent side chains and the chain length of diols were also investigated and optimized. It was found that bulky acyl N-substitutional groups like N-Boc and N-Cbz were more favorable for this polymerization than small ones probably due to competitively binding of these small acyl groups into the active site of Novozym 435. The highest molecular weight can reach up to 39.5 × 103 g/mol (Mw,Đ = 1.64). Moreover, the slow-reacting d-Asp diesters were also successfully polymerized by modifying the substrate structure to create a “nonchiral” condensation environment artificially. These enantiocomplementary chiral polyesters are thermally stable and have specific helical structures, which was confirmed by circular dichroism (CD) spectra, scanning electron microscope (SEM), and molecular calculation.
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高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2024
·
IF 3.9
Limin Ren,Yuxuan Xiao,Rameswar Bhattacharjee,Jingjing Wu,Pengyi Tang,Stavros Caratzoulas,Changgong Meng,Qiang Guo,Michael Tsapatsis
Graphical Bifunctional Ti-B-Beta zeolite is demonstrated to be an efficient catalyst for sorbose production via glucose isomerization. Ethanol directs the conformation of glucose, facilitating its selective isomerization to sorbose and enables this isomerization to surpass the thermodynamic equilibrium limit by engaging in reactions with the resultant sorbose. D-Glucose-to-L-sorbose isomerization on Lewis acidic zeolite is a highly attractive avenue for sorbose production. But the L-sorbose yield is limited by the competing D-glucose-to-D-fructose isomerization and reaction equilibrium. In this work, it is suggested that ethanol directs the glucose conformation for selective D-glucose-to-L-sorbose isomerization. It also reacts with the produced L-sorbose to form ethyl-sorboside, which allows the D-glucose-to-L-sorbose isomerization to proceed beyond the thermodynamic equilibrium limit. It is shown that a bifunctional zeolite Beta containing framework titanium (Ti) and boron (B) is a selective catalyst for this tandem reaction: Lewis acidic framework Ti catalyzes the D-glucose-to-L-sorbose isomerization via an intramolecular 5,1-hydride shift process as confirmed by isotopic tracing experiments followed by 13 C-NMR, while weak Brønsted acid framework B selectively promotes the sorbose ketalization with ethanol. A remarkably high yield of L-sorbose with a high fraction of sugar (>95 %: 27 % unreacted glucose, 11.4 % fructose, 57 % sorbose) was obtained after the mixture produced in ethanol was hydrolyzed.
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高影响因子
BIOSENSORS & BIOELECTRONICS
·
2014
·
IF 6.451
Juying Hou,Jing Dong,Haishuang Zhu,Xue Teng,Shiyun Ai,Minglin Mang
In this paper, a simple and sensitive fluorescent sensor for methyl parathion is developed based on l -tyrosine methyl ester functionalized carbon dots (Tyr-CDs) and tyrosinase system. The carbon dots are obtained by simple hydrothermal reaction using citric acid as carbon resource and l -tyrosine methyl ester as modification reagent. The carbon dots are characterized by transmission electron microscope, high resolution transmission electron microscopy , X-ray diffraction spectrum, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The carbon dots show strong and stable photoluminescence with a quantum yield of 3.8%. Tyrosinase can catalyze the oxidation of tyrosine methyl ester on the surface of carbon dots to corresponding quinone products, which can quench the fluorescence of carbon dots. When organophosphorus pesticides (OPs) are introduced in system, they can decrease the enzyme activity , thus decrease the fluorescence quenching rate. Methyl parathion, as a model of OPs, was detected. Experimental results show that the enzyme inhibition rate is proportional to the logarithm of the methyl parathion concentration in the range 1.0×10 −10 –1.0×10 −4 M with the detection limit ( S / N =3) of 4.8×10 −11 M. This determination method shows a low detection limit, wide linear range, good selectivity and high reproducibility. This sensing system has been successfully used for the analysis of cabbage, milk and fruit juice samples.
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高影响因子
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
·
2020
·
IF 1.431
Yudong Gao
A glassy carbon electrode (GCE) modified with simultaneous electropolymerisation of L-lysine (L-lys) and β-cyclodextrin (β-CD) film (P-β-CD-L-lys/GCE) is proposed as a novel electrochemical platform for the detection of pymetrozine. The electrochemical activity of P-β-CD-L-lys/GCE towards pymetrozine was investigated using cyclic voltammetry experiments in 0.1 M H2SO4. The potential utility of the sensor was demonstrated by applying it to the analytical determination of pymetrozine concentration using linear sweep voltammetry. The linear in the range of 4.0 × 10−8 to 1.0 × 10−6 mol L−1. The detection limit of pymetrozine was found to be 1.3 × 10−8 mol L−1 (S/N = 3). Using this method, we successfully got satisfactory results of pymetrozine in real sample analysis. This work promoted the potential applications of amino acid materials and β-cyclodextrin in environmental analytical chemistry.
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DOI
高影响因子
Arabian Journal of Chemistry
·
2021
·
IF 5.165
Danni Wang,Jiaming Guo,Xin Chai,Jing Yang,Yuefei Wang,Xiumei Gao
Fructus Psoraleae (FP), the dried ripe fruit of Psoralea corylifolia L., is a popular herbal medicine commonly applied for alleviating osteoporosis and vitiligo. But, until now, the dynamic variations of compounds in P. corylifolia have been less investigated during its growth, storage, and treatment by different temperatures, which is meaningful for guaranteeing the quality of FP. In this study, focused on these questions, with emphasis on the enzyme-driven dynamic transformation of coumarins, ultra-high performance liquid chromatography coupled with photodiode array detector (UHPLC-PDA) method was successfully established for the simultaneous determination of nine compounds. The distribution and accumulation of compounds were discussed and illuminated in different parts of P. corylifolia and samples harvested at different times. The characteristics of compounds' variation in flowers and fruits of P. corylifolia were identified. Through the market survey and quantitative study on FP, positive correlation was speculated between transformation from (iso)psoralenoside to (iso)psoralen via β -glucosidase and storage time, which was further confirmed by accelerated stability test. The effect of treated temperatures (40–210 °C) was unveiled on the enzyme activity and transformation from (iso)psoralenoside to (iso)psoralen in FP. And the focused compounds' transformation was mainly driven by β -glucosidase when the temperature was below 120 °C. Above 120 °C, β -glucosidase was completely inactivated, and the focused compounds' transformation was mediated by high-temperature, also the obvious degradation was found. Our results demonstrated that compounds' transformation characteristics arising from the growth, processing and storage of P. corylifolia are critical factors to ensure the quality of FP.
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高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Boyin Yan,Songxue Wang,Zhiquan Liu,Da Wang,Wenxin Shi,Fuyi Cui
In this work, the UV 254 /H 2 O 2 process was utilized to remove β-N-methylamino- l -alanine (BMAA), a kind of cyanobacteria neurotoxin, and the influence of reaction parameters and environmental factors on the degradation of BMAA has been systematically investigated. The results showed that BMAA could be effectively removed in the UV 254 /H 2 O 2 system compared to UV or H 2 O 2 alone and OH was confirmed as the main ROS to degrade BMAA. The degradation rate of BMAA increased first and then decreased with the increase of pH and the maximum k obs was 0.1545 min −1 obtained at pH 9. The removal of BMAA in the UV 254 /H 2 O 2 system was inhibited in actual water, while the degradation rate of BMAA in actual water could still exceed 90% by appropriately extending the reaction time. The decrease in the degradation efficiency of BMAA in actual water was primarily due to the ultraviolet light absorption and competition effects of NOM, and anions (Cl − and HCO 3 − ) would also inhibit the degradation of BMAA. Five by-products ([M − H] - = 118, 103, 88, 87 and 59) were identified in this study and the degradation pathways of BMAA were proposed. The production of by-products was attributed to the fracture of the C–N bond and hydroxylation reaction. This study is worthwhile to deepen the understanding of the degradation mechanism of BMAA in the UV 254 /H 2 O 2 system.
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DOI
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Xuefeng Chen,Lingqi Zhong,Xiao Gong
Poly(l-lactic acid) (PLLA) featuring desirable biodegradability and biocompatibility has been recognized as one of the promising eco-friendly biomaterials. However, low crystallization and poor mechanical and chemical performances dramatically hamper its practical application. In this work, we report that functionalized cellulose/PLLA composite superhydrophobic stereocomplex films with controllable water adhesion and protein adsorption can be fabricated by a facile approach for the first time. First, cellulose is surface-modified by means of two silanization modification methods. Then, superhydrophobic cellulose/PLLA composite films are prepared through a solvent-evaporation-induced phase separation method. The two cellulose/PLLA composite films exhibit extreme water repellency but tunable water adhesion from sticky to slippery. The protein adsorption capacity of the cellulose/PLLA composite films can also be regulated. In addition, the stereocomplexation of the composite film provides excellent mechanical properties with an elongation at break of 22.36%, which is 237.8% higher than that of a pure PLLA film, which is more suitable for biomaterials. Furthermore, good biodegradability of the PLLA composite films in nature enables the bio-based composites as alternative materials to replace conventional petroleum-based polymers. The superhydrophobic films have also been demonstrated for many applications, including slippery surfaces, liquid transportation without loss, and antifouling.
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DOI
PubMed
高影响因子
BIOTECHNOLOGY AND BIOENGINEERING
·
2022
·Vol. 119
·期 7
·1903-1915
·
IF 4.395
Niling He,Jia Jia,Zhongyang Qiu,Chun Fang,Gunnar Lidén,Xiucai Liu,Jie Bao
Cyclic chiral lactide is the monomer chemical for polymerization of high molecular weight polylactic acid (PLA). The synthesis of cyclic l -lactide starts from poly-condensation of l -lactic acid to a low molecular weight prepolymer and then depolymerized to cyclic l -lactide. Lignocellulose biomass is the most promising carbohydrate feedstock for lactic acid production, but the synthesis of cyclic l -lactide from l -lactic acid produced from lignocellulose has so far not been successful. The major barriers are the impurities of residual sugars and inhibitors in the crude cellulosic l -lactic acid product. Here we show a successful cyclic l -lactide synthesis from cellulosic l -lactic acid by lignocellulose biorefining with complete inhibitor removal and coordinated sugars assimilation. The removal of inhibitors from lignocellulose pretreatment was accomplished by biodetoxification using a unique fungus Amorphotheca resinae ZN1. The nonglucose sugars were completely and simultaneously assimilated at the same rate with glucose by the engineered l -lactic acid bacterium Pediococcus acidilactici . The l -lactic acid production from wheat straw was comparable to that from corn starch with high optical pure (99.6%), high l -lactic acid titer (129.4 g/L), minor residual total sugars (~2.2 g/L), and inhibitors free. The cyclic l -lactide was successfully synthesized from the regularly purified l -lactic acid and verified by detailed characterizations. This study paves the technical foundation of carbon-neutral production of biodegradable PLA from lignocellulose biomass.
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DOI
高影响因子
TALANTA
·
2016
·
IF 4.035
Yun Guan,Lanjunzi Liu,Chao Chen,Xiuzhi Kang,Qingji Xie
The facile preparation of poly( l -DOPA)-tyrosinase (PD M -Tyr) composite and its application both in substrate (phenol) and inhibitor (atrazine) sensing is reported here for the first time. Effective immobilization of enzyme is realized via in-situ entrapping Tyr in poly( l -DOPA) (PD M ), which is formed by Tyr catalytic polymerization of l -DOPA. The Tyr modified electrode is simply prepared by dipping the PD M -Tyr composite on an Au electrode and then covered by Nafion. The thus-prepared Tyr-immobilized electrode exhibits excellent performance superior to most Tyr-based electrochemical biosensors, the sensitivity to phenol is as high as 5122 μA mM −1 in the linear range of 10 nM~1.25 μM, the apparent Michaelis-Menten constant ( K M app ) determined as low as 3.13 μM indicates strong substrate binding and high catalytic activity of the immobilized Tyr. The biosensor also works well in atrazine biosensing, with a linear detection range of 50 ppb~30 ppm and a low detection limit of 10 ppb obtained. In addition, the biosensor shows excellent stability, precision, high sensitivity and fabrication simplicity.
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高影响因子
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