JOURNAL OF SEPARATION SCIENCE
·
2013
·
IF 2.591
Xinchun Li,Zuanguang Chen,Fan Yang,Jianbin Pan,Yinbao Li
L -3,4-dihydroxyphenylalanine (L-DOPA) is a well-recognized therapeutic compound to Parkinson's disease. Tyrosine is a precursor for the biosynthesis of L-DOPA, both of which are widely found in traditional medicinal material, Mucuna pruriens . In this paper, we described a validated novel analytical method based on microchip capillary electrophoresis with pulsed electrochemical detection for the simultaneous measurement of L-DOPA and tyrosine in M . pruriens . This protocol adopted end-channel amperometric detection using platinum disk electrode on a homemade glass/polydimethylsiloxane electrophoresis microchip. The background buffer consisted of 10 mM borate (pH 9.5) and 0.02 mM cetyltrimethylammonium bromide, which can produce an effective resolution for the two analytes. In the optimal condition, sufficient electrophoretic separation and sensitive detection for the target analytes can be realized within 60 s. Both tyrosine and L-DOPA yielded linear response in the concentration range of 5.0–400 μM ( R 2 > 0.99), and the LOD were 0.79 and 1.1 μM, respectively. The accuracy and precision of the established method were favorable. The present method shows several merits such as facile apparatus, high speed, low cost and minimal pollution, and provides a means for the pharmacologically active ingredients assay in M . pruriens .
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高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Zhi Li,Qingxiang Zhou,Shuangying Li,Menghua Liu,Yanhui Li,Chunmao Chen
In this study, a label-free “turn off” fluorescent sensor has been resoundingly fabricated using carbon dots (CDs) for ultrasensitive detection of copper ions (Cu 2+ ). CDs are prepared by solid phase carbonization method using p-toluidine and l -cysteine as the precursors. The synthesized CDs exhibited the highest fluorescence intensity with excitation and emission wavelengths set at 300 nm and 400 nm, respectively. The CDs were selective and sensitive to Cu 2+ due to the static quenching mechanism. The concentration of CDs, and solution pH and incubation time were important parameters for the developed sensor. The experimental results showed that 20 mgL −1 was enough for the analysis. As the solution pH was concerned, it was apparent that the sensor was endowed with an excellent response signal to Cu 2+ and provided high sensitivity at pH 12. The interaction occurred very quickly, and the incubation time could be set at 1 min. The sensor provided a two-stage calibration curve to Cu 2+ in the range of 0.05–0.7 and 0.7–4 μM with a limit of detection of 47 nM. The obtained results clearly demonstrated that this facile method was fast, reliable and selective for detecting Cu 2+ , which would explore a prospective strategy for developing effective and low-cost sensors for monitoring metal ions in aqueous environments.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 63
·50747-50755
·
IF 3.84
Bin Jiang,Xiaowei Tantai,Luhong Zhang,Li Hao,Yongli Sun,Lin Deng,Zhiqiang Shi
Polylactic acid (PLA) is a representative biodegradable polymer, which is expected to be a promising replacement for some petroleum-based materials. Noticeably, the properties of PLA products depend strongly on the quality of the lactide monomer, a crucial precursor of PLA production. In this work, a large range of different chlorostannate(II) ionic liquids (ILs), prepared by mixing 1-butyl-3-methyl-imidazolium chloride and tin(II) chloride in various molar ratios, xSnCl2, were firstly applied for the preparation of L-lactide of high chemical and optical purity. The cation–anion interaction, the thermal stability and the acidity of imidazolium-based chlorostannate(II) ionic liquids were experimentally determined and systematically analyzed. Compared with the conventional SnCl2 catalyst, the depolymerization of oligomeric poly(L-lactic acid) catalyzed by chlorostannate(II) ionic liquids occurred in a moderate yield. Interestingly, using [Bmim]Cl–SnCl2 (xSnCl2 = 0.63) as a catalyst, L-lactide of 99.9% optical purity was obtained, simultaneously leaving a high-Mw oligomeric residue with high isotacticity (99.1%). Furthermore, the effects of various reaction parameters were investigated in order to obtain the highest possible yield of lactide. A plausible reaction mechanism was suggested and discussed. Finally, owing to the reutilization of PLLA residue of high isotacticity, a reiterative lactide synthesis was realized. The recycled catalyst showed no notable loss of activity. By combining this chlorostannate(II)-based IL (xSnCl2 = 0.63) catalyst technology with the cyclic resynthesis process, high-quality L-lactide could be selectively produced in high yield (>80%, based on L-lactic acid replenished).
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ying Mao,Malin Cui,Xiaoyan Zhang,Hetong Lin,Da-Peng Yang
To reduce the deterioration of fruits and vegetables caused by food-borne microorganisms, this study proposed a bio-sustainable PCD-CS photothermal bactericidal nanocomposite film. This film integrated L-Cysteine (L-Cys) coated polydopamine nanoparticles (PDA@L-Cys NPs) and deep eutectic solvents (DES) into the chitosan (CS) matrix. The DES effectively improved the mechanical property of composite film, water vapor barrier property (WVP), transparency, and biodegradability. The inclusion of PDA@L-Cys NPs significantly increased the oxidation resistance, UV-shielding, and photothermal conversion capabilities. The oxidation resistance of composite film improved 3–7 times compared to the bare CS film. Under near-infrared irradiation (NIR) for just 10 min, the temperature of the film can rise to 55.8 ℃, achieving a photothermal antibacterial rate reached 99.9% against Escherichia coli ( E. coli , ATCC 8739) and Staphylococcus aureus ( S. aureus , ATCC 6538). Under single short-time NIR trigger, the PCD-CS nanocomposite film effectively maintained good color, pH value, soluble solid content (TSS), and appearance of cherry tomato, and delayed the decrease of weight. The successful implementation of this work provides new insights and approaches for creating and advancing sustainable antibacterial food packaging.
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高影响因子
Journal of Physical Chemistry C
·
2018
·
IF 4.484
Yadong Lian,Xiaokun Huang,Min Gu
Nanocrystalline stannous oxide (SnO) powder has been prepared by ball-milling of micrometer-SnO in a nitrogen atmosphere. A cation deficiency of 6.5% was found in the nano-SnO sample by X-ray photoelectron spectroscopy. After annealing at 350, 450, or 550 °C under dynamic vacuum conditions, oxygen vacancies were found in the nano-SnO samples, as verified by electron paramagnetic resonance experiments. The samples displayed weak ferromagnetism; the sample with both 6.5% Sn and at least 7.5% O vacancies showed the maximum saturation magnetization, reaching almost 1.7 × 10–3 emu/g at room temperature. The O vacancies tended to gather around Sn vacancies. An L-shaped defect model composed of one Sn and two O vacancies has been established, and its ferromagnetism has been calculated by a first-principles method. We found that the L-shaped defect induced a magnetic moment of 0.55 μB in the SnO lattice, the main contribution to which came from a spin-polarized electron in the p orbital of a corner Sn atom.
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高影响因子
Heliyon
·
2021
·
IF 0
Girma Asefa Bogale,Mengistu Mengesha Maja,Gebre Hadgu Gebreyohannes
Climate change is affecting agricultural production and other aspects of life but only limited number of studies took interest in characterizing and projecting climate and its impact on crop production at local level. The threat to agricultural sector is more serious in Ethiopia, where climate is influenced by diverse topography and varying landscape features. This study was conducted in Welmera area to model the impacts of climate change on production of two faba bean ( Vicia faba L.) varieties (Tums and Gora). Historical climate and crop yield data were obtained from the National Meteorological Agency of Ethiopia and Holeta Agricultural Research Center, respectively. Future climate data were downscaled by an average ensemble of four GCMs (BSS-CSM1-1, HadGEM2-ES, MIROC-ESM, NorESM1-M) in near- and mid-century (2030s and 2050s) under both RCP 4.5 and RCP 8.5. Rainfall by near-century will increase by up to 50% depending on the concentration pathway considered compared to the baseline period (1988–2017). The projected average rainfall total of belg season (FMAM) will increase by 88.17% under RCP 4.5 scenario and 95.38% under RCP 8.5 scenario in near-century. The future projection revealed that the highest mean monthly rainfall and temperature changes will occur in July (147.3 mm/month) and August (0.24 °C/month) under RCP8.5. However, in August and September mean monthly rainfall will decrease dramatically by 50.85 % and 31.05% from 2020 to 2079 under RCP 8.5 and RCP 4.5, respectively. The yield of Tumsa variety will decrease by up to 24.19% under RCP8.5 in mid-century. Gora variety will see an increase of yield by 18.24% under RCP 4.5 in mid-century and 28.03% under RCP 8.5 in near-century. Overall, the area will experience an increase and a decrease in faba bean yield for both varieties in the upcoming decades in the study area. Performance evaluation of the models showed that they were able to predict future yield faba bean varieties in the area with acceptable accuracy. Inconsistency of future climate variables and impact on fababean production underscores the need to develop location-specific adaptation strategies. Further studies that consider wider area could be necessary to better understand the impact of future climate on faba bean production in the study area and similar agroecologies in the country.
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PubMed
POSTHARVEST BIOLOGY AND TECHNOLOGY
·
2024
·
IF 6.4
Niu Ye,Dongli Zhang,Shan Liu,Yongqi Zhang,Yifan Wang,Yan Tang,Xiangna Yang,Jiahao Chai,Yanping Ma,Huiling Ma
Browning is the primary physiological damage that shortens the postharvest life and deteriorates the quality of stored fruits. Controlled atmosphere (CA) storage has been shown to be effective in alleviating the browning of ‘Xifu 1′ in-hull walnut; however, its alleviation mechanism is less understood. To further explore the effect and regulatory mechanism of CA on the browning of fresh in-hull walnut, we stored four varieties of in-hull walnuts under CA-treated (5% O 2 + 7.5% CO 2 ) and untreated conditions at 0 ± 0.5 °C with 70–80% relative humidity for 70 d. The indicators related to browning and γ-aminobutyric acid (GABA) metabolism were measured until 56 d of storage. The results showed that the CA significantly increased GABA levels by maintaining higher activities of glutamate decarboxylase (GAD), GABA transaminase (GABAT) and succinate dehydrogenase (SDH). This reduced the changes in the browning index (BI), color values, and respiration rate (RR) of the four walnut fruit varieties compared with controls during storage. Consistent with the active GABA metabolism, higher energy charge (EC) and adenosine triphosphate (ATP), succinic acid (SA), malic acid (MLA), fumaric acid (FA), and citric acid (CTA) contents were also observed in the CA-treated walnut hull compared to the controls. The epicarp degradation of the CA-treated ‘Xifu 1′ walnut fruit occurred later, and their mitochondria and cells maintained better integrity compared to the controls. Among the differentially expressed genes (DEGs) screened via RNA-Sequencing (RNA-Seq), 32 were annotated as part of the citrate cycle (TCA cycle) pathway, and 27 were annotated in the GABA metabolism pathway. Real-time quantitative PCR (RT-qPCR) analysis showed that eight candidate genes were closely related to the effect of CA on the synthesis, transport, and transformation of GABA. In conclusion, CA effectively controlled the browning of different varieties of fresh in-hull walnuts by enhancing GABA metabolism and maintaining energy balance.
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高影响因子
ARCHIV DER PHARMAZIE
·
2024
·
IF 4.3
Xianghao Zeng,Shaobing Cheng,Huilan Li,Haiyang Yu,Yushun Cui,Yuanying Fang,Shilin Yang,Yulin Feng
Alzheimer's disease (AD) is a multifactorial neurological disease, and the multitarget directed ligand (MTDL) strategy may be an effective approach to delay its progression. Based on this strategy, 27 derivatives of l -tryptophan, 3a-1–3d-1 , were designed, synthesized, and evaluated for their biological activity. Among them, IC 50 (inhibitor concentration resulting in 50% inhibitory activity) values of compounds 3a-18 and 3b-1 were 0.58 and 0.44 μM for human serum butyrylcholinesterase ( h BuChE), respectively, and both of them exhibited more than 30-fold selectivity for human serum acetylcholinesterase. Enzyme kinetics studies showed that these two compounds were mixed inhibitors of h BuChE. In addition, these two derivatives possessed extraordinary antioxidant activity in OH radical scavenging and oxygen radical absorption capacity fluorescein assays. Meanwhile, these compounds could also prevent β-amyloid (Aβ) self-aggregation and possessed low toxicity on PC12 and AML12 cells. Molecular modeling studies revealed that these two compounds could interact with the choline binding site, acetyl binding site, and peripheral anionic site to exert submicromolar BuChE inhibitory activity. In the vitro blood–brain barrier permeation assay, compounds 3a-18 and 3b-1 showed enough blood–brain barrier permeability. In drug-likeness prediction, compounds 3a-18 and 3b-1 showed good gastrointestinal absorption and a low risk of human ether-a-go-go-related gene toxicity. Therefore, compounds 3a-18 and 3b-1 are potential multitarget anti-AD lead compounds, which could work as powerful antioxidants with submicromolar selective inhibitory activity for h BuChE as well as prevent Aβ self-aggregation.
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PubMed
高影响因子
ChemistrySelect
·
2025
·Vol. 10
·期 14
·e202500180
·
IF 2
Zhen-zhen Chen,Si-meng Liu,Ran Yang,Ling-bo Qu,Hua-jin Zeng
Graphical Hydrothermally-synthesized GCL-derived carbon dots (2.8nm) exhibited potent antioxidant activity, scavenging DPPH/ABTS radicals and protecting H9c2 cells from H₂O₂ damage. In ISO-induced AMII rats, GCL-CDs reduced ECG S-T elevation, infarct size, and cardiomyocyte apoptosis while promoting tissue repair, likely via oxidative stress alleviation, demonstrating myocardial protection. In this paper, a type of carbon dots (CDs) was prepared at 220°C for 8 h by a hydrothermal method using Geranium carolinianum L. (GCL) as the carbon source. GCL CDs were spherical in shape with the particle size of 2.8 ± 0.6 nm. In vitro studies showed that GCL CDs had a good scavenging activity against the free radicals of DPPH and ABTS, and had a good protective effect against H 2 O 2 -induced oxidative damage of H9c2 cells, suggesting that GCL CDs have good antioxidant activity. In vivo studies showed that GCL CDs had a good protective effect on isoprenaline (ISO)-induced acute myocardial ischemic injury (AMII) in rats, which was reflected by their ability to significantly reduce the S-T band of the electrocardiogram, markedly reduce the infarcted area of AMII, effectively and rapidly restore the damaged cardiomyocytes, and significantly reduce the apoptosis of the cardiomyocytes, which prevented further damage to the cardiomyocytes. The comprehensive results of the above experiments indicate that the protective mechanism of GCL CDs against AMII is probably through the elimination of oxidative stress in the body, so that the damaged cardiomyocytes can be restored, so as to play a protective effect on AMII.
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产品关联
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高影响因子
Drug Metabolism and Pharmacokinetics
·
2019
·
IF 1.874
Yang Zhang,Chen Su,Jinxiu Lei,Lu Chen,Haihong Hu,Su Zeng,Lushan Yu
Mandelic acid (MA) is generally used as a biomarker of the exposure of styrene , which is classified as a class of hazardous environmental pollutants, and also used as an important chiral intermediate in pharmaceutical industry. The previous studies have found the excretion of phenylglyoxylic acid (PGA) in human and rat, a metabolite of MA, was mainly from S- MA rather than R -MA. The metabolic mechanism, however, is not clear. In order to explore the possible metabolic mechanism, the enzyme types involved in the stereoselectivity metabolism of MA were firstly studied, and then human and rat long-chain 2-hydroxy-acid oxidase 2 (HAO2) were recombinantly expressed to study the metabolic profiles of S- MA and its analogues. The results indicated that HAO2 might catalyze the stereoselectivity metabolism of S- MA in rats. Human HAO2 ( h HAO2) and rat HAO2 ( r HAO2) isozymes β 1 and β 2 were successfully cloned and expressed with high purity and good enzyme activities. The enzyme kinetic profiles of these enzymes were different for S- MA and analogues. The order of catalytic efficiency for h HAO2 and r HAO2, however, was reverse. It might be relevance to the difference in active amino acid residues and loop 4 in human and rat L-2-hydroxy acid oxidase isozyme B crystal structures.
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产品关联
DOI
PubMed
高影响因子
Advanced Fiber Materials
·
2024
·Vol. 6
·期 2
·444-457
·
IF 17.2
Xiao Yuanxiang,Jiang Jingjing,Cai Rui,Fu Jiajia,Xiang Shuangfei,Zhao Shujun,Fu Feiya,Diao Hongyan,Liu Xiangdong
Unpredictable pandemics are likely to pose a significant global threat in the future, and biologically protective textiles will play critical roles in controlling the spread of pathogens during outbreaks. Herein, we present a novel metal–organic framework (MOF) composed of repeating units of a Cu(II)/(L-Cys) 2 complex formed through coordination bonds between Cu(II) and L-Cys, while being interconnected by ionic bonds involving Cu(II) and the carboxylate group of L-Cys. After covalently embedding the MOF nanofibers onto cotton fiber surfaces, the resulting fabrics exhibit remarkable virucidal and antibacterial capabilities. Remarkably, even after 200 friction or 50 laundering cycles, the high antiviral ability to inactivate all phi- × 174 within 10 min was maintained, and the bacterial reduction rate against E. coli and S. aureus remained nearly at 100%. The remarkable virucidal effect of the L-Cys@Cu MOF structure is elucidated through a series of α-amylase denaturation simulation tests, providing the first experimental demonstration of the antiviral mechanism, whereby MOF nanofibers induce protein denaturation to inactivate viruses. Moreover, cytotoxicity assessments confirm that the fabrics adorned with MOF nanofibers are safe for human skin. These advantages are promising for the development of protective textiles, highlighting the great potential of nanoscience in combating pandemics. Graphical Abstract
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高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2025
·
IF 5.4
Nguyen Thuy Chinh,Nguyen Thi Thu Trang,Do Quang Tham,Nguyen Duong Bach,Tran Thi Mai,Tran Linh Chi,Tran Thanh Thuy,Nguyen Tuan Anh,Thai Hoang
In this study, a biosynthesis process was applied to decorate silver nanoparticles (AgNPs) on hydrotalcite (HT) surfaces using Allium tuberosum (AT) L. extract as a green reducing agent. The Sapindus saponaria L. fruit extract was used as a biosurfactant to improve the dispersion of HT in an aqueous medium during the synthesis of AgNPs on HT. The technological factors for the biosynthesis process were optimized using the response surface methodology and the Box-Behnken design. Under optimal conditions, the HT-AgNPs-AT hybrid material (HTAgAT) was characterized by Infrared spectroscopy, Ultraviolet–visible diffuse reflectance spectroscopy, Dynamic light scattering, Scanning electron microscopy, Transmission electron microscopy, Energy dispersive X-ray-Mapping, X-ray diffraction, Inductively coupled plasma mass spectrometry, and Thermogravimetric analysis methods. Additionally, the antimicrobial activity of the HTAgAT hybrid material was assessed on E. coli , S. aureus , antibiotic-resistant E. coli , and C. albicans strains. The results confirmed that AgNPs were formed and uniformly distributed on the surface of the HT carrier. The HTAgAT hybrid material exhibited significant antimicrobial activity, which could be sustained for a long time. Furthermore, the HTAgAT hybrid material can remarkably enhance the surface properties and antimicrobial activity of chitosan membranes. The findings suggest that HTAgAT materials are promising for applications in biopolymer composites and antimicrobial materials.
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高影响因子
危险品化学品经营许可证（带存储）