Determination of the transformation of ginsenosides in Ginseng Radix et Rhizoma during decoction with water using ultra-fast liquid chromatography coupled with tandem mass spectrometry

This study was conducted to determine the variations of ginsenosides in Ginseng Radix et Rhizoma when using different preparation solvents, and explore the major factors for changes. With an established ultra-fast liquid chromatography coupled with tandem mass spectrometry method which could quantify 52 ginsenosides, the extraction differences were characterized and compared using different solvents (water, 70% aqueous ethanol and ethanol). Subsequently, a series of aqueous solutions with different pH were prepared to test the influence of pH to the changes of ginsenosides. Meanwhile, acetic acid and aspartic acid were used to verify whether the reaction had a relationship with the kind of acids. After refluxing with water, not only highly polar ginsenosides were extracted, some less polar ginsenosides such as ginsenoside Rg3, Rg5, Rk1 and Rh2 occurred or increased rapidly. Further experiments indicated that less polar ginsenosides were easier to generate at low pH values, and the reaction was only related to pH other than what kind of acids. It is the first time to elaborate the contents variation of 52 ginsenosides when using different extraction methods. The results indicated decoction with water could enhance the transformation of highly polar ginsenosides to less polar ginsenosides and the process was pH dependent.
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Abstract

This study was conducted to determine the variations of ginsenosides in Ginseng Radix et Rhizoma when using different preparation solvents, and explore the major factors for changes. With an established ultra-fast liquid chromatography coupled with tandem mass spectrometry method which could quantify 52 ginsenosides, the extraction differences were characterized and compared using different solvents (water, 70% aqueous ethanol and ethanol). Subsequently, a series of aqueous solutions with different pH were prepared to test the influence of pH to the changes of ginsenosides. Meanwhile, acetic acid and aspartic acid were used to verify whether the reaction had a relationship with the kind of acids. After refluxing with water, not only highly polar ginsenosides were extracted, some less polar ginsenosides such as ginsenoside Rg3, Rg5, Rk1 and Rh2 occurred or increased rapidly. Further experiments indicated that less polar ginsenosides were easier to generate at low pH values, and the reaction was only related to pH other than what kind of acids. It is the first time to elaborate the contents variation of 52 ginsenosides when using different extraction methods. The results indicated decoction with water could enhance the transformation of highly polar ginsenosides to less polar ginsenosides and the process was pH dependent.

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A robust, portable and backflow-free micromixing device based on both capillary- and vacuum-driven flows

Lab Chip, 2018, Advance ArticleDOI: 10.1039/C7LC01077J, PaperYaguang Zhai, Anyang Wang, Domin Koh, Philip Schneider, Kwang W. OhA robust, portable and backflow-free micromixing device using capillary-driven bypassing and syringe-assisted vacuum-driven …

Lab Chip, 2018, Advance Article
DOI: 10.1039/C7LC01077J, Paper
Yaguang Zhai, Anyang Wang, Domin Koh, Philip Schneider, Kwang W. Oh
A robust, portable and backflow-free micromixing device using capillary-driven bypassing and syringe-assisted vacuum-driven pumping shows great promise for a variety of blood typing assays, agglutination-based assays and point-of-care or lab-on-a-chip testing applications.
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Converting Colour to Length Based on Coffee-Ring Effect for Quantitative Immunoassays Using a Ruler as Readout

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC01127J, CommunicationDagan Zhang, Bingbing Gao, Yangtian Chen, Hong liuWe report a method for converting the colorimetric results of enzyme-link immunosorbent assay (ELISA) into length based on the co…

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC01127J, Communication
Dagan Zhang, Bingbing Gao, Yangtian Chen, Hong liu
We report a method for converting the colorimetric results of enzyme-link immunosorbent assay (ELISA) into length based on the coffee-ring effect, so that the quantitative detection of analyte can be...
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Chiral separation of disease biomarkers with 2-hydroxycarboxylic acid structure#

Chiral 2-hydroxycarboxylic acids are compounds that have been linked to particular diseases and are putative biomarkers with some diagnostic potential. The importance of identifying whether a particular enantiomer is related to certain diseases has been encouraged recently. However, in many cases it has not yet been elucidated whether there are stereochemical implications with respect to these biomarkers and whether their enantioselective analysis provides new insights and diagnostic potential. In this study 13 disease-related chiral 2-hydrocarboxylic acids were studied for their chiral separation by high-performance liquid chromatography on three cinchona alkaloid-derived chiral stationary phases. From a subgroup of eight 2-hydroxymonocarboxylic acids, baseline resolution could be achieved and inversion of elution order by exchanging tert-butylcarbamoyl quinidine chiral stationary phase (Chiralpak QD-AX) for the corresponding quinine analogue (Chiralpak QN-AX) is shown for seven of them. Furthermore, conditions for chiral separation of the 2-hydroxydicarboxylic acids, citramalic acid, 2-isopropylmalic acid and 2-hydroxyadipic acid are reported and compared to the previous reported conditions for 2-hydroxyglutaric acid and malic acid.
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Abstract

Chiral 2-hydroxycarboxylic acids are compounds that have been linked to particular diseases and are putative biomarkers with some diagnostic potential. The importance of identifying whether a particular enantiomer is related to certain diseases has been encouraged recently. However, in many cases it has not yet been elucidated whether there are stereochemical implications with respect to these biomarkers and whether their enantioselective analysis provides new insights and diagnostic potential. In this study 13 disease-related chiral 2-hydrocarboxylic acids were studied for their chiral separation by high-performance liquid chromatography on three cinchona alkaloid-derived chiral stationary phases. From a subgroup of eight 2-hydroxymonocarboxylic acids, baseline resolution could be achieved and inversion of elution order by exchanging tert-butylcarbamoyl quinidine chiral stationary phase (Chiralpak QD-AX) for the corresponding quinine analogue (Chiralpak QN-AX) is shown for seven of them. Furthermore, conditions for chiral separation of the 2-hydroxydicarboxylic acids, citramalic acid, 2-isopropylmalic acid and 2-hydroxyadipic acid are reported and compared to the previous reported conditions for 2-hydroxyglutaric acid and malic acid.

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A simple approach to prepare a sulfone-embedded stationary phase for HPLC

In the present study, a polar-embedded reversed-phase liquid chromatographic stationary phase which contained internal sulfone groups was prepared. The synthesis involved the “thiol-ene” click chemistry between the vinyl functionalized silica and 1-octadecanethiol, followed by the oxidization of sulfide to sulfone groups. The resulting material simultaneously possessed the alkyl chain, i.e. C18, and the internal sulfone groups. Elemental analysis demonstrates that the element contents of the C18/sulfone silica were C 8.94%, H 1.87% and S 0.66%. Chromatographic evaluations indicate that the C18/sulfone stationary phase exhibited a little less retention than the C18/sulfide one. A comparable chromatographic performance of neutral analytes was obtained on these two columns, but much better chromatographic performance in the case of basic and acid analytes was obtained on C18/sulfone stationary phase with additional features such as lower silanol activity, better stability (stable working conditions of pH 1.0–10.0) and better compatibility with 100% aqueous mobile phases. The batch-to-batch reproducibility was acceptable (the RSDs of retention times for the probes were no higher than 1.73%), demonstrating the suitability of the applied synthetic strategy for the new stationary phase. The C18/sulfone is a promising polar-embedded RPLC stationary phase.
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Abstract

In the present study, a polar-embedded reversed-phase liquid chromatographic stationary phase which contained internal sulfone groups was prepared. The synthesis involved the “thiol-ene” click chemistry between the vinyl functionalized silica and 1-octadecanethiol, followed by the oxidization of sulfide to sulfone groups. The resulting material simultaneously possessed the alkyl chain, i.e. C18, and the internal sulfone groups. Elemental analysis demonstrates that the element contents of the C18/sulfone silica were C 8.94%, H 1.87% and S 0.66%. Chromatographic evaluations indicate that the C18/sulfone stationary phase exhibited a little less retention than the C18/sulfide one. A comparable chromatographic performance of neutral analytes was obtained on these two columns, but much better chromatographic performance in the case of basic and acid analytes was obtained on C18/sulfone stationary phase with additional features such as lower silanol activity, better stability (stable working conditions of pH 1.0–10.0) and better compatibility with 100% aqueous mobile phases. The batch-to-batch reproducibility was acceptable (the RSDs of retention times for the probes were no higher than 1.73%), demonstrating the suitability of the applied synthetic strategy for the new stationary phase. The C18/sulfone is a promising polar-embedded RPLC stationary phase.

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Real-time two-photon-lithography in controlled flow to create a single-microparticle-array and particle-cluster-array for optofluidic imaging

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC01080J, PaperBing Xu, Yang Shi, Zhao-Xin Lao, Jin-Cheng Ni, Guoqiang Li, Yanlei Hu, Jiawen Li, Jia-ru Chu, Dong Wu, Koji SugiokaMicroarray technology provides an excellent platform for biomedical and …

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC01080J, Paper
Bing Xu, Yang Shi, Zhao-Xin Lao, Jin-Cheng Ni, Guoqiang Li, Yanlei Hu, Jiawen Li, Jia-ru Chu, Dong Wu, Koji Sugioka
Microarray technology provides an excellent platform for biomedical and biochemical research including basic scientific studies, drug-discovery, and diagnostics. Here, we develop a novel method referred to as real-time two-photon-lithography in...
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On-chip label-free protein analysis with downstream electrodes for direct removal of electrolysis products

Lab Chip, 2017, Advance Article
DOI: 10.1039/C7LC00797C, Paper
Open Access Open Access
Creative Commons Licence&nbsp This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Kadi L. Saar, Yingbo Zhang, Thomas Muller, Challa P. Kumar, Sean Devenish, Andrew Lynn, Urszula Lapinska, Xiaoting Yang, Sara Linse, Tuomas P. J. Knowles
Single-layer lithography microfluidic devices for applying high and stable electric fields on chip.
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Lab Chip, 2017, Advance Article
DOI: 10.1039/C7LC00797C, Paper
Open Access Open Access
Creative Commons Licence  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Kadi L. Saar, Yingbo Zhang, Thomas Muller, Challa P. Kumar, Sean Devenish, Andrew Lynn, Urszula Lapinska, Xiaoting Yang, Sara Linse, Tuomas P. J. Knowles
Single-layer lithography microfluidic devices for applying high and stable electric fields on chip.
To cite this article before page numbers are assigned, use the DOI form of citation above.
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Cyclic Olefin Copolymer as an X-ray compatible material for microfluidic devices

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC00824D, PaperManuela Denz, Gerrit Brehm, Clement Hemonnot, Heidi M Spears, Andrew Wittmeier, Chiara Cassini, Oliva Saldanha, Eleonora Perego, Ana Diaz, Manfred Burghammer, Sarah KosterThe combination …

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC00824D, Paper
Manuela Denz, Gerrit Brehm, Clement Hemonnot, Heidi M Spears, Andrew Wittmeier, Chiara Cassini, Oliva Saldanha, Eleonora Perego, Ana Diaz, Manfred Burghammer, Sarah Koster
The combination of microfluidics and X-ray methods attracts a lot of attention from researchers as it brings together the high controllability of microfluidic sample environments and the small length scales...
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Front Cover: Polymethacrylate-based monoliths as stationary phases for separation of biopolymers and immobilization of enzymes

Electrophoresis 2017, 38, 2821–2826. DOI: 10.1002/elps.201700255
The cover picture shows the structure of polymethacrylate-based monolithic supports and their use for the chromatographic separation end enzymatic conversions of small and large molecu…

Thumbnail image of graphical abstract

Electrophoresis 2017, 38, 2821–2826. DOI: 10.1002/elps.201700255

The cover picture shows the structure of polymethacrylate-based monolithic supports and their use for the chromatographic separation end enzymatic conversions of small and large molecules. The characteristic structure of the monolith as seen by scanning electron microscopy is shown in the middle, and it is surrounded by the schematic presentation of different applications - chromatographic separation and enzymatic conversion of small and large molecules as well as viruses and nanoparticles.

Headspace solid-phase microextraction and gas chromatographic analysis of low-molecular-weight sulfur volatiles with pulsed flame photometric detection and quantification by a stable isotope dilution assay

Low-molecular-weight volatile sulfur compounds such as thiols, sulfides, disulfides as well as thioacetates cause a sulfidic off-flavor in wines even at low concentration levels. The proposed analytical method for quantification of these compounds in wine is based on headspace solid-phase microextraction, followed by gas chromatographic analysis with sulfur-specific detection using a pulsed flame photometric detector. Robust quantification was achieved via a stable isotope dilution assay using commercial and synthesized deuterated isotopic standards. The necessary chromatographic separation of analytes and isotopic standards benefits from the inverse isotope effect realized on an apolar polydimethylsiloxane stationary phase of increased film thickness. Interferences with sulfur-specific detection in wine caused by sulfur dioxide were minimized by addition of propanal. The method provides adequate validation data, with good repeatability and limits of detection and quantification. It suits the requirements of wine quality management, allowing the control of oenological treatments to counteract an eventual formation of excessively high concentration of such malodorous compounds.
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Abstract

Low-molecular-weight volatile sulfur compounds such as thiols, sulfides, disulfides as well as thioacetates cause a sulfidic off-flavor in wines even at low concentration levels. The proposed analytical method for quantification of these compounds in wine is based on headspace solid-phase microextraction, followed by gas chromatographic analysis with sulfur-specific detection using a pulsed flame photometric detector. Robust quantification was achieved via a stable isotope dilution assay using commercial and synthesized deuterated isotopic standards. The necessary chromatographic separation of analytes and isotopic standards benefits from the inverse isotope effect realized on an apolar polydimethylsiloxane stationary phase of increased film thickness. Interferences with sulfur-specific detection in wine caused by sulfur dioxide were minimized by addition of propanal. The method provides adequate validation data, with good repeatability and limits of detection and quantification. It suits the requirements of wine quality management, allowing the control of oenological treatments to counteract an eventual formation of excessively high concentration of such malodorous compounds.

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Analysis and measurement of serotonin

Serotonin, also known as 5-hydroxytryptamine, is an important signaling molecule in the central and peripheral nervous systems of humans. Acting through several receptor types, it helps regulate the normal functioning of the gastrointestinal tract, cardiovascular system and brain. Serotonin signaling has also been implicated in the etiology of several diseases, including depression, anxiety disorders, hypertension and irritable bowel syndrome. The present review focuses on the chemical analysis of serotonin in biological fluids and biomatrices and traces the development and application of early methods based on UV absorbance or fluorescence to more widely used current methods such as high-performance liquid chromatography coupled to mass spectrometry. A brief summary of the biochemistry, metabolism and physiological roles of serotonin is also presented.

Abstract

Serotonin, also known as 5-hydroxytryptamine, is an important signaling molecule in the central and peripheral nervous systems of humans. Acting through several receptor types, it helps regulate the normal functioning of the gastrointestinal tract, cardiovascular system and brain. Serotonin signaling has also been implicated in the etiology of several diseases, including depression, anxiety disorders, hypertension and irritable bowel syndrome. The present review focuses on the chemical analysis of serotonin in biological fluids and biomatrices and traces the development and application of early methods based on UV absorbance or fluorescence to more widely used current methods such as high-performance liquid chromatography coupled to mass spectrometry. A brief summary of the biochemistry, metabolism and physiological roles of serotonin is also presented.

On-demand acoustic droplet splitting and steering in a disposable microfluidic chip

Lab Chip, 2017, Accepted ManuscriptDOI: 10.1039/C7LC01083D, PaperJinsoo Park, Jin Ho Jung, Kwangseok Park, Ghulam Destgeer, Husnain Ahmed, Raheel Ahmad, Hyung Jin SungOn-chip droplet splitting is one of fundamental droplet-based microfluidic unit opera…

Lab Chip, 2017, Accepted Manuscript
DOI: 10.1039/C7LC01083D, Paper
Jinsoo Park, Jin Ho Jung, Kwangseok Park, Ghulam Destgeer, Husnain Ahmed, Raheel Ahmad, Hyung Jin Sung
On-chip droplet splitting is one of fundamental droplet-based microfluidic unit operations to control droplet volume after production and increase operational capability, flexibility, and throughput. Various droplet splitting methods reported to...
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