The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jinmao You - One of the best experts on this subject based on the ideXlab platform.
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novel Fluorescence Labeling reagent 4 carbazole 9 yl benzyl chloroformate and its application in the determination of nitrofuran metabolites compounds in foodstuffs by high performance liquid chromatography with Fluorescence detection
Microchemical Journal, 2019Co-Authors: Qianqian Jin, Jinmao You, Zhiwei Sun, Shijuan ZhangAbstract:Abstract The goal of the presented work is to develop a simple and sensitive high-performance liquid chromatography in combination with Fluorescence detection (HPLC-FLD) method for the determination of four nitrofurans (NFs) metabolites compounds (semicarbazide (SEM), 1-aminohydantoin (AH), 3-amino-2-oxazolidinone (AOZ) and 3-amino-morpholinomethyl-2-oxazolidinone (AMOZ)) in foodstuffs. For this goal, we synthesized a novel Fluorescence Labeling reagent, 4-(carbazole-9-yl)-benzyl chloroformate (CBBC) to label NFs metabolites compounds. NFs metabolites compounds can be labeled rapidly only within 5 min at the room temperature (25 °C). The labeled derivatives showed excellent Fluorescence property with maximum excitation and emission wavelengths of 375 nm and 410 nm, respectively. The labeled derivatives were analyzed on a reversed-phase Eclipse XDB-C18 column within 10 min. Excellent linearity (R2 > 0.995) of all NFs metabolites compounds was achieved with the limits of detection (LODs) and the limits of quantitations (LOQs) in the low micrograms per kilogram range of 0.20–0.30 μg·kg−1 and 0.70–1.00 μg·kg−1, respectively. Satisfactory recoveries in the range of 92.5–98.0% were obtained for all NFs metabolites compounds. Using the proposed HPLC-FLD method, we successfully determined four NFs metabolites compounds in different foodstuffs. As promising, this highly sensitive and reliable method would also be extended for the quantitation of NFs metabolites compounds in other samples.
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hplc determination of γ aminobutyric acid and its analogs in human serum using precolumn Fluorescence Labeling with 4 carbazole 9 yl benzyl chloroformate
IEEE Journal of Solid-state Circuits, 2019Co-Authors: Jinmao You, Zhiwei Sun, Wu Zhou, Xuxia ZhouAbstract:In this study, a simple analytical method for the determination of γ-aminobutyric acid, gabapentin, and baclofen by using high-performance liquid chromatography with Fluorescence detection was developed. An amidogen-reactive Fluorescence Labeling reagent, 4-(carbazole-9-yl)-benzyl chloroformate was first used to sensitively label these analytes. The completed Labeling of these analytes can be finished rapidly only within 5 min at the room temperature (25°C) to form 4-(carbazole-9-yl)-benzyl chloroformate labeled Fluorescence derivatives. These labeled derivatives expressed strong Fluorescence property with the maximum excitation and emission wavelengths of 280 and 380 nm, respectively. The labeled derivatives were analyzed using a reversed-phase Eclipse SB-C18 column within 10 min with satisfactory shapes. Excellent linearity (R2 > 0.995) for all analytes was achieved with the limits of detection and the limits of quantitation in the range of 0.25-0.35 and 0.70-1.10 μg/L, respectively. The proposed method was used for the simultaneous determination of γ-aminobutyric acid and its analogs in human serum with satisfactory recoveries in the range of 94.5-97.5%.
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simultaneous determination of seven biogenic amines in foodstuff samples using one step Fluorescence Labeling and dispersive liquid liquid microextraction followed by hplc fld and method optimization using response surface methodology
Food Analytical Methods, 2015Co-Authors: Shucheng Liu, Jinmao You, Qiulong Zhang, Yourui SuoAbstract:A simple, sensitive and selective method based on one-step Fluorescence Labeling and ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) was developed for the determination of biogenic amines (BAs) in foodstuff samples by high-performance liquid chromatography (HPLC) with Fluorescence detection (FLD). In this work, Fluorescence probe 2-(11H-benzo[a]carbazol-11-yl) ethyl carbonochloridate (BCEC-Cl) was applied to label BAs. What followed was the UA-DLLME procedure that was carried out using chloroform and acetone as extraction and disperser solvents, respectively. A response surface methodology (RSM) based on a Box-Behnken design (BBD) was employed to optimize the main parameters affecting the Fluorescence Labeling and DLLME efficiency. Under the optimal conditions, this method offered low limits of detection (LODs) of 1.1-7.8 ng/mL and limits of quantification (LOQs) of 3.5-26.1 ng/mL. Finally, the method was successfully used for the determination of trace BAs in real samples and exhibited powerful potential in the high-throughput sample screening.
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iron catalyzed three component tandem process a novel and convenient synthetic route to quinoline 2 4 dicarboxylates from arylamines glyoxylic esters and α ketoesters
ChemInform, 2014Co-Authors: Wei Wei, Jinmao You, Yourui Suo, Jiangwei Wen, Daoshan Yang, Xuejun Sun, Hua WangAbstract:The new multicomponent reaction of aromatic amines, glyoxylic esters, and α-ketoesters provides an attractive approach to a series of functionalized quinoline derivatives with promising unique pharmaceutical, biological, and Fluorescence-Labeling applications.
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simultaneous determination of biogenic amines and estrogens in foodstuff by an improved hplc method combining with Fluorescence Labeling
Lwt - Food Science and Technology, 2014Co-Authors: Lihua Dong, Aihong Wang, Wenli Wang, Jinmao YouAbstract:Biogenic amines (BA) and estrogens (ES) have attracted increasing attentions due to their significance on food safety and food quality. In this study, a novel HPLC-FLD method using ethyl-acridine-sulfonyl chloride (EAC) as Fluorescence Labeling reagent has been developed for simultaneous determination of BA and ES in food samples. The Labeling conditions including Labeling time, pH of borate buffers and amount of EAC were optimized. The simultaneous Labeling of BA and ES can be finished in as little as 6 min. This method without complex pre-treatment offered the low LOD of 0.27-0.69 ng/mL. It was applied to analyze several food samples (beer, cheese, fish, sausage and shrimp), and showed excellent applicability. (C) 2013 Elsevier Ltd. All rights reserved.
Jacob Piehler - One of the best experts on this subject based on the ideXlab platform.
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specific and stable Fluorescence Labeling of histidine tagged proteins for dissecting multi protein complex formation
Journal of the American Chemical Society, 2006Co-Authors: Suman Lata, Martynas Gavutis, Robert Tampe, Jacob PiehlerAbstract:Labeling of proteins with fluorescent dyes offers powerful means for monitoring protein interactions in vitro and in live cells. Only a few techniques for noncovalent Fluorescence Labeling with well-defined localization of the attached dye are currently available. Here, we present an efficient method for site-specific and stable noncovalent Fluorescence Labeling of histidine-tagged proteins. Different fluorophores were conjugated to a chemical recognition unit bearing three NTA moieties (tris-NTA). In contrast to the transient binding of conventional mono-NTA, the multivalent interaction of tris-NTA conjugated fluorophores with oligohistidine-tagged proteins resulted in complex lifetimes of more than an hour. The high selectivity of tris-NTA toward cumulated histidines enabled selective Labeling of proteins in cell lysates and on the surface of live cells. Fluorescence Labeling by tris-NTA conjugates was applied for the analysis of a ternary protein complex in solution and on surfaces. Formation of the co...
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specific and stable Fluorescence Labeling of histidine tagged proteins for dissecting multi protein complex formation
Journal of the American Chemical Society, 2006Co-Authors: Suman Lata, Martynas Gavutis, Robert Tampe, Jacob PiehlerAbstract:Labeling of proteins with fluorescent dyes offers powerful means for monitoring protein interactions in vitro and in live cells. Only a few techniques for noncovalent Fluorescence Labeling with well-defined localization of the attached dye are currently available. Here, we present an efficient method for site-specific and stable noncovalent Fluorescence Labeling of histidine-tagged proteins. Different fluorophores were conjugated to a chemical recognition unit bearing three NTA moieties (tris-NTA). In contrast to the transient binding of conventional mono-NTA, the multivalent interaction of tris-NTA conjugated fluorophores with oligohistidine-tagged proteins resulted in complex lifetimes of more than an hour. The high selectivity of tris-NTA toward cumulated histidines enabled selective Labeling of proteins in cell lysates and on the surface of live cells. Fluorescence Labeling by tris-NTA conjugates was applied for the analysis of a ternary protein complex in solution and on surfaces. Formation of the complex and its stoichiometry was studied by analytical size exclusion chromatography and Fluorescence quenching. The individual interactions were dissected on solid supports by using simultaneous mass-sensitive and multicolor Fluorescence detection. Using these techniques, formation of a 1:1:1 stoichiometry by independent interactions of the receptor subunits with the ligand was shown. The incorporation of transition metal ions into the labeled proteins upon Labeling with tris-NTA fluorophore conjugates provided an additional sensitive spectroscopic reporter for detecting and monitoring protein-protein interactions in real time. A broad application of these Fluorescence conjugates for protein interaction analysis can be envisaged.
Suman Lata - One of the best experts on this subject based on the ideXlab platform.
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specific and stable Fluorescence Labeling of histidine tagged proteins for dissecting multi protein complex formation
Journal of the American Chemical Society, 2006Co-Authors: Suman Lata, Martynas Gavutis, Robert Tampe, Jacob PiehlerAbstract:Labeling of proteins with fluorescent dyes offers powerful means for monitoring protein interactions in vitro and in live cells. Only a few techniques for noncovalent Fluorescence Labeling with well-defined localization of the attached dye are currently available. Here, we present an efficient method for site-specific and stable noncovalent Fluorescence Labeling of histidine-tagged proteins. Different fluorophores were conjugated to a chemical recognition unit bearing three NTA moieties (tris-NTA). In contrast to the transient binding of conventional mono-NTA, the multivalent interaction of tris-NTA conjugated fluorophores with oligohistidine-tagged proteins resulted in complex lifetimes of more than an hour. The high selectivity of tris-NTA toward cumulated histidines enabled selective Labeling of proteins in cell lysates and on the surface of live cells. Fluorescence Labeling by tris-NTA conjugates was applied for the analysis of a ternary protein complex in solution and on surfaces. Formation of the co...
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specific and stable Fluorescence Labeling of histidine tagged proteins for dissecting multi protein complex formation
Journal of the American Chemical Society, 2006Co-Authors: Suman Lata, Martynas Gavutis, Robert Tampe, Jacob PiehlerAbstract:Labeling of proteins with fluorescent dyes offers powerful means for monitoring protein interactions in vitro and in live cells. Only a few techniques for noncovalent Fluorescence Labeling with well-defined localization of the attached dye are currently available. Here, we present an efficient method for site-specific and stable noncovalent Fluorescence Labeling of histidine-tagged proteins. Different fluorophores were conjugated to a chemical recognition unit bearing three NTA moieties (tris-NTA). In contrast to the transient binding of conventional mono-NTA, the multivalent interaction of tris-NTA conjugated fluorophores with oligohistidine-tagged proteins resulted in complex lifetimes of more than an hour. The high selectivity of tris-NTA toward cumulated histidines enabled selective Labeling of proteins in cell lysates and on the surface of live cells. Fluorescence Labeling by tris-NTA conjugates was applied for the analysis of a ternary protein complex in solution and on surfaces. Formation of the complex and its stoichiometry was studied by analytical size exclusion chromatography and Fluorescence quenching. The individual interactions were dissected on solid supports by using simultaneous mass-sensitive and multicolor Fluorescence detection. Using these techniques, formation of a 1:1:1 stoichiometry by independent interactions of the receptor subunits with the ligand was shown. The incorporation of transition metal ions into the labeled proteins upon Labeling with tris-NTA fluorophore conjugates provided an additional sensitive spectroscopic reporter for detecting and monitoring protein-protein interactions in real time. A broad application of these Fluorescence conjugates for protein interaction analysis can be envisaged.
Isaac Cann - One of the best experts on this subject based on the ideXlab platform.
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quantitative Fluorescence Labeling of aldehyde tagged proteins for single molecule imaging
Nature Methods, 2012Co-Authors: Xinghua Shi, Yonil Jung, Li Jung Lin, Cheng Liu, Isaac CannAbstract:A major hurdle for molecular mechanistic studies of many proteins is the lack of a general method for Fluorescence Labeling with high efficiency, specificity and speed. By incorporating an aldehyde motif genetically into a protein and improving the Labeling kinetics substantially under mild conditions, we achieved fast, site-specific Labeling of a protein with ∼100% efficiency while maintaining the biological function. We show that an aldehyde-tagged protein can be specifically labeled in cell extracts without protein purification and then can be used in single-molecule pull-down analysis. We also show the unique power of our method in single-molecule studies on the transient interactions and switching between two quantitatively labeled DNA polymerases on their processivity factor.
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quantitative Fluorescence Labeling of aldehyde tagged proteins for single molecule imaging
Nature Methods, 2012Co-Authors: Xinghua Shi, Yonil Jung, Li Jung Lin, Cheng Liu, Isaac CannAbstract:The combination of a genetically encoded aldehyde tag and optimized Labeling method allows high-efficiency, site-specific Labeling of tagged proteins after purification or in cell extracts. The authors use the high Labeling efficiency for single-molecule measurements of the dynamic interactions between two DNA polymerases and polymerase processivity factor bound to DNA.
Xinghua Shi - One of the best experts on this subject based on the ideXlab platform.
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quantitative Fluorescence Labeling of aldehyde tagged proteins for single molecule imaging
Nature Methods, 2012Co-Authors: Xinghua Shi, Yonil Jung, Li Jung Lin, Cheng Liu, Isaac CannAbstract:A major hurdle for molecular mechanistic studies of many proteins is the lack of a general method for Fluorescence Labeling with high efficiency, specificity and speed. By incorporating an aldehyde motif genetically into a protein and improving the Labeling kinetics substantially under mild conditions, we achieved fast, site-specific Labeling of a protein with ∼100% efficiency while maintaining the biological function. We show that an aldehyde-tagged protein can be specifically labeled in cell extracts without protein purification and then can be used in single-molecule pull-down analysis. We also show the unique power of our method in single-molecule studies on the transient interactions and switching between two quantitatively labeled DNA polymerases on their processivity factor.
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quantitative Fluorescence Labeling of aldehyde tagged proteins for single molecule imaging
Nature Methods, 2012Co-Authors: Xinghua Shi, Yonil Jung, Li Jung Lin, Cheng Liu, Isaac CannAbstract:The combination of a genetically encoded aldehyde tag and optimized Labeling method allows high-efficiency, site-specific Labeling of tagged proteins after purification or in cell extracts. The authors use the high Labeling efficiency for single-molecule measurements of the dynamic interactions between two DNA polymerases and polymerase processivity factor bound to DNA.