The Experts below are selected from a list of 654 Experts worldwide ranked by ideXlab platform
Huantsung Chang - One of the best experts on this subject based on the ideXlab platform.
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accurate quantitation of glutathione in cell lysates through surface assisted laser desorption ionization mass spectrometry using gold nanoparticles
Nanomedicine: Nanotechnology Biology and Medicine, 2010Co-Authors: Chengkang Chiang, Yangwei Lin, Wen Tsen Chen, Huantsung ChangAbstract:Abstract We developed a method for the determination of three Aminothiols—cysteine, glutathione (GSH), and homocysteine—using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The analytes were first captured using the unmodified 14-nm gold nanoparticles; N-2-mercaptopropionylglycine–modified gold nanoparticles serving as internal standard were sequentially added, and then the sample was analyzed using SALDI-MS. This approach provided good quantitative linearity of the three analytes (R2 = ∼0.99), with good reproducibility (relative standard deviations: From the Clinical Editor This paper reports the development of a surface assisted laser desorption/ionization mass spectrometry method to precisely determine Aminothiols-cysteine (Cys), glutathione (GSH), and homocysteine (HCys)
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nile red adsorbed gold nanoparticle matrixes for determining Aminothiols through surface assisted laser desorption ionization mass spectrometry
Analytical Chemistry, 2006Co-Authors: Yufen Huang, Huantsung ChangAbstract:This paper describes the use of Nile Red-adsorbed gold nanoparticles (NRAuNPs) as selective probes and matrixes for the determination of Aminothiols through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The binding of three Aminothiolsglutathione (GSH), cysteine (Cys), and homocysteine (HCys)to the surfaces of these NRAuNPs induces their aggregation, which causes asubsequent changes in their color and fluorescence. Because argininea non-thiol amino aciddoes not induce such aggregation, it is a straightforward process to use the NRAuNPs to selectively concentrate the Aminothiols from a solution containing all four of these analytes; we were able to identify the three Aminothiols in the precipitate, and arginine in the supernatant, directly through SALDI-MS measurements. Without using this preconcentration approach, the limits of detection (LODs) at a signal-to-noise ratio of 3 were 1.0, 2.0, and 1.3 μM for GSH, Cys, and HCys, respectively. In comparison, selective concentration...
Yann Seimbille - One of the best experts on this subject based on the ideXlab platform.
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a flexible synthesis of 68ga labeled carbonic anhydrase ix caix targeted molecules via cbt 1 2 Aminothiol click reaction
Molecules, 2018Co-Authors: Kuoting Chen, Christian Ieritano, Kevin Nguyen, Feng Gao, Yann SeimbilleAbstract:We herein describe a flexible synthesis of a small library of 68Ga-labeled CAIX-targeted molecules via an orthogonal 2-cyanobenzothiazole (CBT)/1,2-Aminothiol click reaction. Three novel CBT-functionalized chelators (1⁻3) were successfully synthesized and labeled with the positron emitter gallium-68. Cross-ligation between the pre-labeled bifunctional chelators (BFCs) and the 1,2-Aminothiol-acetazolamide derivatives (8 and 9) yielded six new 68Ga-labeled CAIX ligands with high radiochemical yields. The click reaction conditions were optimized to improve the reaction rate for applications with short half-life radionuclides. Overall, our methodology allows for a simple and efficient radiosynthetic route to produce a variety of 68Ga-labeled imaging agents for tumor hypoxia.
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two bifunctional desferrioxamine chelators for bioorthogonal labeling of biovectors with zirconium 89
Organic and Biomolecular Chemistry, 2018Co-Authors: Christian Ieritano, Kuoting Chen, Gemma Dias, Julie Rousseau, Francois Benard, Yann SeimbilleAbstract:We report two bifunctional chelators, DFO-Cys and DFO-CBT, to label biovectors with zirconium-89 according to the 2-cyanobenzothiazole/1,2-Aminothiol cycloaddition. Their features are high labeling yields, rapid and efficient bioconjugation, metabolically stable luciferin-based end products, and applicability to orthogonal two-step labeling of sensitive biomolecules.
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early stage incorporation strategy for regioselective labeling of peptides using the 2 cyanobenzothiazole 1 2 Aminothiol bioorthogonal click reaction
ChemistryOpen, 2018Co-Authors: Kuoting Chen, Christian Ieritano, Yann SeimbilleAbstract:Invited for this month's cover picture is the group of Dr. Yann Seimbille at the Life Sciences Division at TRIUMF (Canada). The cover picture shows how a simple and innovative methodology based on the bioorthogonal click reaction between 2-cyanobenzothiazole and 1,2-Aminothiol has been elaborated to facilitate the labeling of peptide biovectors. Read the full text of their Communication at 10.1002/open.201700191.
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A Flexible Synthesis of 68Ga-Labeled Carbonic Anhydrase IX (CAIX)-Targeted Molecules via CBT/1,2-Aminothiol Click Reaction
'MDPI AG', 2018Co-Authors: Kuoting Chen, Christian Ieritano, Kevin Nguyen, Feng Gao, Yann SeimbilleAbstract:We herein describe a flexible synthesis of a small library of 68Ga-labeled CAIX-targeted molecules via an orthogonal 2-cyanobenzothiazole (CBT)/1,2-Aminothiol click reaction. Three novel CBT-functionalized chelators (1–3) were successfully synthesized and labeled with the positron emitter gallium-68. Cross-ligation between the pre-labeled bifunctional chelators (BFCs) and the 1,2-Aminothiol-acetazolamide derivatives (8 and 9) yielded six new 68Ga-labeled CAIX ligands with high radiochemical yields. The click reaction conditions were optimized to improve the reaction rate for applications with short half-life radionuclides. Overall, our methodology allows for a simple and efficient radiosynthetic route to produce a variety of 68Ga-labeled imaging agents for tumor hypoxia
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chemoselective ligation of 2 cyanobenzothiazole with 1 2 Aminothiol a novel approach to label biomolecules
2016Co-Authors: Christian Ieritano, Yann SeimbilleAbstract:Poster: "EANM 16 / EPW93 / Chemoselective ligation of 2-cyanobenzothiazole with 1,2-Aminothiol: a novel approach to label biomolecules" by: "C. Ieritano, Y. Seimbille; BC, Vancouver, CANADA"
Weilung Tseng - One of the best experts on this subject based on the ideXlab platform.
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gold nanoparticle extraction followed by capillary electrophoresis to determine the total free and protein bound Aminothiols in plasma
Analytical Chemistry, 2010Co-Authors: Chungwei Chang, Weilung TsengAbstract:This study describes the use of Tween 20−capped gold nanoparticles (Tween 20−AuNPs) for the selective extraction and enrichment of five Aminothiols, including glutathione, γ-glutamylcysteine, cysteine, homocysteine, and cysteineglycine, prior to analysis by capillary electrophoresis with UV detection. Tween 20−AuNPs are capable of extracting Aminothiols from a complicated matrix because a Tween 20 capping layer can inhibit effectively the nonspecific adsorption. Moreover, Tween 20−AuNPs had better Aminothiol loading compared to Zonyl FSN-100- and Triton X-100−capped AuNPs. The extraction efficiency of Aminothiols was highly dependent on the number of Tween 20−AuNPs, the concentration of dithiothreitol, and the type of surfactant (i.e., capping agent). Under optimal extraction conditions, the limits of detection at a signal-to-noise ratio of 3 for five Aminothiols were down to 10−65 nM. Total and free Aminothiols in plasma were determined by varying the order of disulfide reduction with tris(2-carboxyethyl...
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selective enrichment of Aminothiols using polysorbate 20 capped gold nanoparticles followed by capillary electrophoresis with laser induced fluorescence
Journal of Chromatography A, 2009Co-Authors: Chienchih Shen, Weilung Tseng, Mingmu HsiehAbstract:Abstract In this article, we report a simple method for selective enrichment of Aminothiols using Tween 20-capped gold nanoparticles (AuNPs) prior to capillary electrophoresis coupled with laser-induced fluorescence (CE-LIF). Compared to citrate-capped AuNPs, Tween 20-capped AuNPs exhibit the ability to disperse in a highly saline solution and selectively extract Aminothiols through the formation of Au–S bonds. After extraction and centrifugation, 1 mM thioglycollic acid (TGA) was utilized to remove Aminothiols that attached to the NP surfaces. After a solution of 8.0 mL Aminothiols were extracted using 2× AuNPs (200 μL), the extracted Aminothiols derivatized with o -phthalaldehyde at pH 12.0 were detected by CE-LIF. As a result, the limits of detection at a signal-to-noise ratio of 3 for homocysteine (HCys), glutathione (GSH), and γ-glutamycysteine (Glu-cys) are 4013.2, 79.8, and 382.8 pM, respectively. The use of this probe provided approximately 11-, 282-, and 21-fold sensitivity improvements for HCys, GSH, and Glu-cys, respectively. A practical analysis of HCys, GSH, and Glu-cys in human urine sample has been accomplished by this present method.
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role of fluorosurfactant modified gold nanoparticles in selective detection of homocysteine thiolactone remover and sensor
Analytical Chemistry, 2008Co-Authors: Chiachi Huang, Weilung TsengAbstract:In this article, we report a simple approach for the selective sensing of homocysteine thiolactone (HTL) using fluorosurfactant (FSN)-capped gold nanoparticles (AuNPs) as Aminothiol removers and as sensors. We have shown that HTL did not bind to the surface of the FSN-AuNPs in the pH range of 4.0−10.0. In contrast, under these pH conditions, the FSN-AuNPs are aggregated upon the addition of homocysteine (HCys) and cysteine (Cys). On the basis of this feature, we have demonstrated that FSN-AuNPs are effective sorbent materials for HCys and Cys, but not for HTL. It is found that the FSN-AuNPs can remove of >98% of HCys and >99% of Cys from an aqueous solution. Thus, after the centrifugation of a solution containing AuNPs, HTL, and other Aminothiols, only HTL remains in the supernatant. When NaOH is added to the supernatant, HTL is hydrolyzed to HCys, leading to the aggregation of the FSN-AuNPs. As a result, the selectivity of the probe is significantly higher for HTL in aqueous solutions than for other amin...
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role of fluorosurfactant modified gold nanoparticles in selective detection of homocysteine thiolactone remover and sensor
Analytical Chemistry, 2008Co-Authors: Chiachi Huang, Weilung TsengAbstract:In this article, we report a simple approach for the selective sensing of homocysteine thiolactone (HTL) using fluorosurfactant (FSN)-capped gold nanoparticles (AuNPs) as Aminothiol removers and as sensors. We have shown that HTL did not bind to the surface of the FSN-AuNPs in the pH range of 4.0-10.0. In contrast, under these pH conditions, the FSN-AuNPs are aggregated upon the addition of homocysteine (HCys) and cysteine (Cys). On the basis of this feature, we have demonstrated that FSN-AuNPs are effective sorbent materials for HCys and Cys, but not for HTL. It is found that the FSN-AuNPs can remove of >98% of HCys and >99% of Cys from an aqueous solution. Thus, after the centrifugation of a solution containing AuNPs, HTL, and other Aminothiols, only HTL remains in the supernatant. When NaOH is added to the supernatant, HTL is hydrolyzed to HCys, leading to the aggregation of the FSN-AuNPs. As a result, the selectivity of the probe is significantly higher for HTL in aqueous solutions than for other aminthiols. The sensitivity of FSN-AuNPs toward HTL can be further improved by optimizing the AuNP concentrations. Under optimum conditions, the lowest detectable concentration of HTL through this approach is 100 nM. We have validated the applicability of our method through the analyses of HTL in urine samples.
Chengkang Chiang - One of the best experts on this subject based on the ideXlab platform.
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accurate quantitation of glutathione in cell lysates through surface assisted laser desorption ionization mass spectrometry using gold nanoparticles
Nanomedicine: Nanotechnology Biology and Medicine, 2010Co-Authors: Chengkang Chiang, Yangwei Lin, Wen Tsen Chen, Huantsung ChangAbstract:Abstract We developed a method for the determination of three Aminothiols—cysteine, glutathione (GSH), and homocysteine—using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The analytes were first captured using the unmodified 14-nm gold nanoparticles; N-2-mercaptopropionylglycine–modified gold nanoparticles serving as internal standard were sequentially added, and then the sample was analyzed using SALDI-MS. This approach provided good quantitative linearity of the three analytes (R2 = ∼0.99), with good reproducibility (relative standard deviations: From the Clinical Editor This paper reports the development of a surface assisted laser desorption/ionization mass spectrometry method to precisely determine Aminothiols-cysteine (Cys), glutathione (GSH), and homocysteine (HCys)
Kuoting Chen - One of the best experts on this subject based on the ideXlab platform.
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a flexible synthesis of 68ga labeled carbonic anhydrase ix caix targeted molecules via cbt 1 2 Aminothiol click reaction
Molecules, 2018Co-Authors: Kuoting Chen, Christian Ieritano, Kevin Nguyen, Feng Gao, Yann SeimbilleAbstract:We herein describe a flexible synthesis of a small library of 68Ga-labeled CAIX-targeted molecules via an orthogonal 2-cyanobenzothiazole (CBT)/1,2-Aminothiol click reaction. Three novel CBT-functionalized chelators (1⁻3) were successfully synthesized and labeled with the positron emitter gallium-68. Cross-ligation between the pre-labeled bifunctional chelators (BFCs) and the 1,2-Aminothiol-acetazolamide derivatives (8 and 9) yielded six new 68Ga-labeled CAIX ligands with high radiochemical yields. The click reaction conditions were optimized to improve the reaction rate for applications with short half-life radionuclides. Overall, our methodology allows for a simple and efficient radiosynthetic route to produce a variety of 68Ga-labeled imaging agents for tumor hypoxia.
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two bifunctional desferrioxamine chelators for bioorthogonal labeling of biovectors with zirconium 89
Organic and Biomolecular Chemistry, 2018Co-Authors: Christian Ieritano, Kuoting Chen, Gemma Dias, Julie Rousseau, Francois Benard, Yann SeimbilleAbstract:We report two bifunctional chelators, DFO-Cys and DFO-CBT, to label biovectors with zirconium-89 according to the 2-cyanobenzothiazole/1,2-Aminothiol cycloaddition. Their features are high labeling yields, rapid and efficient bioconjugation, metabolically stable luciferin-based end products, and applicability to orthogonal two-step labeling of sensitive biomolecules.
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early stage incorporation strategy for regioselective labeling of peptides using the 2 cyanobenzothiazole 1 2 Aminothiol bioorthogonal click reaction
ChemistryOpen, 2018Co-Authors: Kuoting Chen, Christian Ieritano, Yann SeimbilleAbstract:Invited for this month's cover picture is the group of Dr. Yann Seimbille at the Life Sciences Division at TRIUMF (Canada). The cover picture shows how a simple and innovative methodology based on the bioorthogonal click reaction between 2-cyanobenzothiazole and 1,2-Aminothiol has been elaborated to facilitate the labeling of peptide biovectors. Read the full text of their Communication at 10.1002/open.201700191.
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A Flexible Synthesis of 68Ga-Labeled Carbonic Anhydrase IX (CAIX)-Targeted Molecules via CBT/1,2-Aminothiol Click Reaction
'MDPI AG', 2018Co-Authors: Kuoting Chen, Christian Ieritano, Kevin Nguyen, Feng Gao, Yann SeimbilleAbstract:We herein describe a flexible synthesis of a small library of 68Ga-labeled CAIX-targeted molecules via an orthogonal 2-cyanobenzothiazole (CBT)/1,2-Aminothiol click reaction. Three novel CBT-functionalized chelators (1–3) were successfully synthesized and labeled with the positron emitter gallium-68. Cross-ligation between the pre-labeled bifunctional chelators (BFCs) and the 1,2-Aminothiol-acetazolamide derivatives (8 and 9) yielded six new 68Ga-labeled CAIX ligands with high radiochemical yields. The click reaction conditions were optimized to improve the reaction rate for applications with short half-life radionuclides. Overall, our methodology allows for a simple and efficient radiosynthetic route to produce a variety of 68Ga-labeled imaging agents for tumor hypoxia