MOLECULES
·
2018
·Vol. 23
·期 10
·2663
·
IF 3.098
Tian Chai,Xiao-Bo Zhao,Wei-Feng Wang,Yin Qiang,Xiao-Yun Zhang,Jun-Li Yang
Gx-50 is a bioactive compound for the treatment of Alzheimer’s disease (AD) found in Sichuan pepper (Zanthoxylum bungeanum). In order to find a stronger anti-AD lead compound, 20 gx-50 (1–20) analogs have been designed and synthesized, and their molecular structures were determined based on nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis, as well as comparison with literature data. Compounds1–20were evaluated for their anti-AD potential by using DPPH radical scavenging assay for considering their anti-oxidant activity, thioflavin T (ThT) fluorescence assay for considering the inhibitory or disaggregate potency of Aβ, and transgenicDrosophilamodel assay for evaluating their rescue effect on memory loss. Finally, compound13was determined as a promising anti-AD candidate.Keywords:Alzheimer’s disease;gx-50;DPPH assay;ThT assay;transgenicDrosophilamodel assay
研究领域:
药理学
·
神经科学
·
化学
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产品关联
DOI
PubMed
高影响因子
Natural Product Communications
·
2014
·
IF 0.924
Zihao Zhou,Jun Tang,Xueping Song
The chemical composition of the essential oil from roots and rhizomes of Ligularia hodgsonii was analyzed by gas chromatography (GC) and GC-mass spectrometry (MS). Forty-seven components were identified, representing 77.0% of the total oil. The main constituents were l-(+)-ascorbic acid 2,6-dihexadecanoate (15.7%), selina-6-en-4-ol (8.4%) and 9,10-dimethyl-1,2,3,4,5,6,7,8-octahydroanthracene (6.6%). The free radical scavenging activities of the essential oil, aqueous extract, ethanolic extract, and crude polysaccharides of L. hodgsonii, as well as some of their major components, were investigated using DPPH and ABTS assays. The essential oil displayed a lower capacity to quench free radicals than the extracts; the ethanolic and aqueous extracts showed considerably higher antioxidant potential that deserves further study.
研究领域:
植物化学
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药理学
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DOI
高影响因子
ANALYST
·
2020
·Vol. 145
·期 19
·6254-6261
·
IF 3.978
Guoyan Zhang,Meihao Xiang,Rong-Mei Kong,Fengli Qu
Determination of glutathione (GSH) is closely related to the clinical diagnosis of many diseases. Thus, a fluorescent and colorimetric dual-readout strategy for the sensitive determination of glutathione was proposed. The mesoporous silica nanoparticle–gold nanocluster (MSN–AuNC) nanocomposites with significantly enhanced emission and effectively improved photostability characteristics were used as fluorescent probes. Based on the inner filter effect (IFE), the fluorescence of MSN–AuNCs at 570 nm can be effectively quenched by oxidized 3,3′,5,5′-tetramethylbenzidine (oxTMB) with absorption in the wavelength ranges of 330–470 nm and 500–750 nm. However, the addition of GSH could cause the reduction of blue oxTMB to colorless TMB, resulting in the inhibition of IFE and the recovery of the fluorescence of MSN–AuNCs. Therefore, using oxTMB as both quencher and color indicator, a dual-readout oxTMB/MSN–AuNC sensing system for the sensitive determination of GSH was constructed. As signal amplification is caused by the fluorescence enhancement of MSN–AuNCs, the detection limits as low as 0.12 μM and 0.34 μM can be obtained for fluorescent and colorimetric assay, respectively. This method may not only offer a new idea for the sensitive and effective determination of GSH, but also broaden the applications of AuNCs in fluorescent and colorimetric dual-readout bioanalysis.
研究领域:
生物分析化学
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医学诊断
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DOI
PubMed
高影响因子
Biosensors-Basel
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2022
·Vol. 12
·期 8
·668
·
IF 5.743
Xiang Li,Junsong Wu,Huaguang Hu,Fangfang Liu,Jialian Wang
A desirable lanthanide-based ratiometric fluorescence probe was designed as a multifunctional nanoplatform for the determination of dipicolinic acid (DPA), a unique bacterial endospore biomarker, with high selectivity and sensitivity. The carbon dots (CDs) with blue emission wavelengths at 470 nm are developed with europium ion (Eu3+) to form Eu3+/CDs fluorescent probes. DPA can specifically combine with Eu3+and then transfer energy from DPA to Eu3+sequentially through the antenna effect, resulting in a distinct increase in the red fluorescence emission peak at 615 nm. The fluorescence intensity ratio of Eu3+/CDs (fluorescence intensity at 615 nm/fluorescence intensity at 470 nm) showed good linearity and low detection limit. The developed ratiometric nanoplatform possesses great potential for application in complex matrices owing to its specificity for DPA. In addition, the integration of a smartphone with the Color Picker APP installed enabled point-of-care testing (POCT) with quantitative measurement capabilities, confirming the great potential of the as-prepared measurement platform for on-site testing.Keywords:ratiometric;fluorescence;determination of dipicolinic acid;smartphone-based detection
研究领域:
生物化学
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分析化学
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微生物学
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DOI
PubMed
高影响因子
CHEMISTRY OF NATURAL COMPOUNDS
·
2020
·Vol. 56
·期 5
·821-826
·
IF 0.653
Shao Jin,Zhao Tong,Ma Hui-Ping,Jia Zheng-Ping,Jing Lin-Lin
A convergent synthesis route of 6-hydroxygenistein (6-OHG) was reported, starting from cheap and readily available biochanin A, via methylation, bromination, methoxylation, and demethylation. The structure of the products was confirmed by MS, IR, 1 H NMR, and 13 C NMR analysis. The antiradical activity of 6-OHG was determined using six different methods, namely, DPPH assay, ABTS assay, nitric oxide assay, superoxide assay, reducing power assay, and phosphomolybdenum assay using ascorbic acid (V C ) as positive control. The results show that 6-OHG possesses similar or greater antiradical activity than V C . In conclusion, 6-OHG can be useful as an antioxidant agent.
研究领域:
有机化学
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药物化学
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天然产物化学
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DOI
高影响因子
SENSORS
·
2018
·Vol. 18
·期 8
·2525
·
IF 2.475
Zhengjun Huang,Linlin Zheng,Feng Feng,Yuyuan Chen,Zhenzhen Wang,Zhen Lin,Xinhua Lin,Shaohuang Weng
Simple and effective methods for the detection of the level of blood glucose are closely linked to the monitoring of people’s health. In the study, MnO2nanosheets with absorption range of 300 nm~500 nm and obvious yellow color were easily prepared and applied to detect glucose through their absorbance and color. The proposed method is based on the fact that a specific concentration of glucose can be quantitatively transformed into hydrogen peroxide (H2O2) under the catalytic effect of glucose oxidase. Based on the redox reaction of MnO2with H2O2, yellow MnO2can be converted into colorless Mn2+to monitor the concentration of glucose. Under optimal conditions, a simple and effective visual assay for the sensitive and reliable detection of glucose was developed. The linear range was estimated to the range from 0 μM to 100 μM, with a detection limit of 12.8 μM. Furthermore, the proposed colorimetric assay based on MnO2nanosheets can effectively detect blood glucose of clinical serum samples with accuracy and convenience.Keywords:glucose;colorimetric assay;MnO2nanosheets;UV-vis;quantitative determination
研究领域:
生物化学
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医学检测
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产品关联
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2022
·
IF 5.122
Changfang Lu,Yutong Wang,Wei Zhang,Yu Zhang,Yinyin Chen,Gang Xiang,Xianxiang Wang
The crosslinking of glutaraldehyde (GA) and nano-selenium coated chitosan (CS-SeNPs) afforded composites (GA–CS–SeNPs) which exhibit new properties. In addition to having mimic enzyme activity of CS-SeNPs, these composites exhibit fluorescence, which CS-SeNPs did not possess. The GA–CS–SeNPs can catalyze the chromogenic process of oxidation of substrate TMB at 20 °C and pH of 3.5, and under the excitation wavelength of 440 nm, the composites can emit strong fluorescence. The presence of mercury (II) (Hg 2+ ) inhibited the color process of catalytic oxidation of 3,3,5,5, -tetramethylbenzidine (TMB) and enhanced the fluorescence intensity of the composites to some extent. Therefore, using the fluorescence and mimicking enzyme properties of GA–CS–SeNPs, a fluorescent and colorimetric (dual-mode) determination of Hg 2+ was developed with good selectivity and high sensitivity. The linear determination ranges of Hg 2+ were 0–55 μM and 0–50 μM for fluorescent and colorimetric assays, respectively, and the limits of detection (LOD) for the dual-mode assay were as low as 0.34 μM and 0.40 μM, respectively. In addition, this new method was successfully implemented for dual-mode determination of Hg 2+ in real samples.
研究领域:
分析化学
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环境科学
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生物材料学
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产品关联
DOI
高影响因子
MOLECULES
·
2017
·Vol. 22
·期 1
·171
·
IF 2.861
Xiangcong Wang,Maocai Yan,Qibao Wang,Huannan Wang,Zhengyang Wang,Jiayi Zhao,Jing Li,Zhen Zhang
Indole-2-carboxylic acid copper complex (ICA-Cu) was successfully prepared and characterized through elemental analysis, IR, UV-Vis,1H-NMR, TG analysis, and molar conductance, and its molecular formula was [Cu2(C9H6O2N)4(H2O)2]·2H2O. The binding ability of ICA-Cu to calf thymus DNA (CT-DNA) was examined by fluorescence spectrometry and the viscosity method. The results indicated that, upon the addition of increasing amounts of CT-DNA, the excitation and emission intensity of ICA-Cu decreased obviously and the excitation spectra shifted towards a long wavelength. ICA-Cu could displace ethidium bromide (EB) from the EB-DNA system, making the fluorescence intensity of the EB-DNA system decrease sharply; the quenching constantKSVvalue was 3.99 × 104M−1. The emission intensity of the ICA-Cu-DNA system was nearly constant, along with the addition of Na+in a series of concentrations. The fluorescence of the complex could be protected after the complex interacted with DNA. A viscosity measurement further supported the result that the ICA-Cu complex may interact with DNA in an intercalative binding mode. The antioxidant activities of ICA-Cu were evaluated by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, a hydroxyl radical (OH) scavenging assay, and a 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay. The ICA-Cu exhibited the highest inhibitory effects on the ABTS radical (94% inhibition at 60 µM), followed by OH and DPPH radicals (the degrees of inhibition being 71% and 56%, respectively). The in vitro cytotoxicity activity of ICA-Cu against two human breast cancer cell lines, MDA-MB-231 and MCF-7, was investigated by 3-[4,5-dimethyltiazol2-yl]-2.5-diphenyl-tetrazolium bromide (MTT) assay and cellular morphological analysis. The results showed that, upon increasing the concentration of ICA-Cu, an increase was observed in growth-inhibitory activity and the inhibition percentage were greater than 90% at 20 µM in both cell lines. Also, cellular morphological changes in the two cell lines agreed with the cytotoxicity results.Keywords:DNA-binding;antioxidant;anticancer;indole-2-carboxylicacid;copper(II) complexes
研究领域:
化学
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生物化学
·
药理学
·
癌症研究
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产品关联
DOI
PubMed
高影响因子
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2014
·Vol. 239
·期 3
·385-391
·
IF 1.387
Zou Bo,Dong Xiao-qian,Ge Zhen-zhen,Xu Ze,Du Jing,Li Chun-mei
Use of gallic acid (GA) as a standard in the Folin-Ciocalteu assay leads to an underestimation of phenol content in persimmon extracts so does the widely used catechin (C) in vanillin assay for determining condensed tannins in persimmon extracts. To develop suitable standards for addressing the issue of accuracy, we prepared highly purified persimmon tannin (PT) and its three fractions (PT20, PT40 and PT60), as well as three characteristic structural subunits of PT including epicatechin-3-gallate-(4β → 8, 2β → O→7)-epicatechin-3-gallate (A-type ECG dimer), epigallocatechin-3-gallate-(4β → 8, 2β → O→7)-epigallocatechin-3-gallate (A-type EGCG dimer) and epicatechin-(4β → 8)-epicatechin (B-type EC dimer). We compared the color yield of commercially available standards including the dimers GA, EGCG, ECG, C and PT and its three fractions in the Folin-Ciocalteu assay and vanillin assay, respectively. Our results suggested that for estimating phenol content in persimmon extracts, EGCG, ECG, C and GA were poor standards in Folin-Ciocalteu assay. We recommended PT40 as the most suitable standard in determining the phenol content of persimmon extracts. In the vanillin assay, A-type EGCG dimer or A-type ECG dimer were superior than the commonly used C as standards, and ECG was also an alternative when A-type EGCG dimer or A-type ECG dimer were not available.
研究领域:
植物化学
·
分析化学
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产品关联
DOI
高影响因子
ANALYTICAL BIOCHEMISTRY
·
2025
·
IF 2.5
Jiaxu Wang,Zhengrong Lu,Zhanmin Liu,Qiming Chen
Copy number of cell-free mitochondrial DNA (cf-mtDNA) has garnered significant attention as a biomarker for studying and diagnosing various diseases. However, Quantitative Real-time PCR (qPCR) and Droplet Digital PCR (ddPCR) assays for cf-mtDNA copy number detection require expensive equipment and high experiment conditions. In this study, a colorimetric and fluorescent dual-modality assay was developed for quantitative detection of cf-mtDNA copy number. With G-quadruplex (G4) sequence modified primers, the assay could quantitatively detect cf-mtDNA with spectrophotometry, RGB (Red, Green, Blue) visual method and fluorescence method, which made the application scenarios more diverse. The specificity of dual-mode method was better, and the detection limits of spectrophotometry, RGB visual method and fluorescence method were as low as 1.45 × 10 −1 copies/μL, 1.65 copies/μL and 1.58 × 10 −1 copies/μL, respectively. Compared with qPCR and ddPCR assays developed in previous studies, the dual-modality assay in this study had a lower detection limit. It was also independent of expensive qPCR and ddPCR equipment and the detection cost was low. Therefore, the colorimetric and fluorescent dual-modality assay represent a label-free and sensitive approach for assessing cf-mtDNA levels, offering promising implications for biomedical research and clinical diagnostics.
研究领域:
医学诊断
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
Foods
·
2022
·Vol. 11
·期 23
·3763
·
IF 5.561
Fan Zhang,Hongxia Du,Linsen Li,Tengfei Li,Jing Wang,Zilei Chen,Mengmeng Yan,Chao Zhu,Feng Qu
Lactoferrin (Lf), as a popular nutritional fortification in dairy products, has the ability regulate the body’s immune system and function as a broad-spectrum antibacterial, which is of great significance to the growth and development of infants and children. Herein, an indirect competitive enzyme-linked aptamer assay (ELAA) kit was established for rapid, sensitive, and visual determination of Lf in dairy products. In the construction, the Lf aptamer was conjugated with horseradish peroxidase (HRP) as the recognition probe and aptamer complementary strand (cDNA) were anchored onto the microplate as the capture probe. The recognition probes were first mixed with a sample solution and specifically bound with the contained Lf, then added into the microplate in which the free recognition probes in the mixture were captured by the capture probe. After washing, the remaining complex of cDNA/Aptamer/HRP in the microplate was conducted with a chromogenic reaction through HRP, efficiently catalyzing the substrate 3, 3′, 5, 5′-tetramethylbenzidine (TMB), therefore the color shade would directly reflect Lf concentration. Under the optimization conditions, a good linear relationship (R2, 0.9901) was obtained in the wide range of 25–500 nM with the detection limit of 14.01 nM and a good specificity, as well as the reliable recoveries. Furthermore, the ELAA kits achieved the Lf determination with an accuracy of 79.71~116.99% in eleven samples, which consisted of three kinds of dairy products: including goat milk powder, cow milk powder, and nutrition drop. Moreover, the results were also validated by the high-performance capillary electrophoresis (HPCE) method. The ELAA kit provides a simple and convenient determination for Lf in dairy products, and it is highly expected to be commercialized.Keywords:aptamer;lactoferrin determination;enzyme-linked aptamer assay;colorimetric;capillary electrophoresis
研究领域:
分析化学
·
食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
CHEMBIOCHEM
·
2021
·Vol. 22
·期 11
·1948-1954
·
IF 3.164
Yaoyao Hou,Jianjun Hou,Xixia Liu
Graphical Two very different DNA aptamers have been reported for dopamine, one derived from an RNA aptamer (named Apt1) and other obtained via direct aptamer selection (named Apt2). In this study, we used four homogeneous binding assays to compare these two DNA dopamine aptamers. Apt1 does not appear to be able to bind dopamine specifically, while Apt2 showed specific binding and could be used for developing related biosensors. Dopamine is an essential neurotransmitter and its detection is important for bioanalytical chemistry. Two very different DNA aptamers have been reported for dopamine, one derived from an RNA aptamer (named Apt1) and other obtained via direct aptamer selection (named Apt2). In this study, we used four homogeneous binding assays to compare these two DNA dopamine aptamers. Thiazole orange (TO) fluorescence assay indicated that the Apt2 specifically bound with dopamine with a K d of 2.37 μM, which was consistent with that from the isothermal titration calorimetry (ITC) assay. However, Apt1 had much less TO fluorescence change and also no signal from ITC. By labeling the two ends of the two aptamers by a fluorophore and a quencher, the aptamer beacons showed binding of dopamine only for Apt2. Finally, the label-free AuNP-based colorimetric assay showed no difference between these two aptamer sequences, and even non-binding random DNA showed the same response, indicating that AuNPs were not a good probe for detecting dopamine. According to the data, Apt1 does not appear to be able to bind dopamine specifically, while Apt2 showed specific binding and could be used for developing related biosensors.
研究领域:
分析化学
·
生物化学
·
生物传感器开发
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）