The Experts below are selected from a list of 7797 Experts worldwide ranked by ideXlab platform
Jeffrey W Bode - One of the best experts on this subject based on the ideXlab platform.
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synthesis of chemically and configurationally stable monofluoro acylboronates effect of Ligand Structure on their formation properties and reactivities
ChemInform, 2015Co-Authors: Hidetoshi Noda, Jeffrey W BodeAbstract:The reaction of a range of bidentate N-containing Ligands with acyltrifluoroborates is examined for the formation of novel monofluoro acylborates which are stable to air and water.
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synthesis of chemically and configurationally stable monofluoro acylboronates effect of Ligand Structure on their formation properties and reactivities
Journal of the American Chemical Society, 2015Co-Authors: Hidetoshi Noda, Jeffrey W BodeAbstract:The recent disclosures of two classes of acylborons, potassium acyltrifluoroborates (KATs) and N-methyliminodiacetyl (MIDA) acylboronates, demonstrated that certain acylboron species can be both remarkably stable and uniquely reactive. Here we report new classes of Ligands for acylboronates that have a significant influence on the formation, properties, and reactivities of acylboronates. Our systematic investigations identified a class of neutral, monofluoroboronates that can be prepared in a one step, gram-scale fashion from readily accessible KATs. These monofluoroboronates are stable to air, moisture, and silica gel chromatography and can be easily handled without any special precautions. X-ray crystallography, NMR spectroscopy, and HPLC studies showed that they are tetravalent, configurationally stable B-chiral acylboronates. Significantly, the Ligands on the boronate allow for fine-tuning of the properties and reactivity of acylboronates. In amide-forming ligation with hydroxylamines under aqueous co...
Marcus Tullius Scotti - One of the best experts on this subject based on the ideXlab platform.
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Selection of antileishmanial sesquiterpene lactones from SistematX database using a combined Ligand-/Structure-based virtual screening approach
Molecular Diversity, 2020Co-Authors: Chonny Herrera-acevedo, Mayara Santos Maia, Élida Batista Vieira Sousa Cavalcanti, Ericsson Coy-barrera, Luciana Scotti, Marcus Tullius ScottiAbstract:Leishmaniasis refers to a complex of diseases, caused by the intracellular parasitic protozoans belonging to the genus Leishmania . Among the three types of disease manifestations, the most severe type is visceral leishmaniasis, which is caused by Leishmania donovani , and is diagnosed in more than 20,000 cases annually, worldwide. Because the current therapeutic options for disease treatment are associated with several limitations, the identification of new potential leads/drugs remains necessary. In this study, a combined approach was used, based on two different virtual screening (VS) methods, which were designed to select promising antileishmanial agents from among the entire sesquiterpene lactone (SL) dataset registered in SistematX, a web interface for managing a secondary metabolite database that is accessible by multiple platforms on the Internet. Thus, a ChEMBL dataset, including 3159 and 1569 Structures that were previously tested against L. donovani amastigotes and promastigotes in vitro, respectively, was used to develop two random forest models, which performed with greater than 74% accuracy in both the cross-validation and test sets. Subsequently, a Ligand-based VS assay was performed against the 1306 SistematX-registered SLs. In parallel, the crystal Structures of three L. donovani target proteins, N -myristoyltransferase, ornithine decarboxylase, and mitogen-activated protein kinase 3, and a homology model of pteridine reductase 1 were used to perform a Structure-based VS, using molecular docking, of the entire SistematX SL dataset. The consensus analysis of these two VS approaches resulted in the normalization of probability scores and identified 13 promising, enzyme-targeting, antileishmanial SLs from SistematX that may act against L. donovani . Graphic abstract A combined approach based on two different virtual screening methods (Structure-based and Ligand-based) was performed using an in-house dataset composed of 1306 sesquiterpene lactones to identify potential antileishmanial ( Leishmania donovani ) Structures.
Kyösti Kontturi - One of the best experts on this subject based on the ideXlab platform.
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influence of Ligand Structure on the stability and oxidation of copper nanoparticles
Journal of Colloid and Interface Science, 2008Co-Authors: Petri Kanninen, Juha Merta, Christoffer Johans, Kyösti KontturiAbstract:Abstract The stability and oxidation of copper nanoparticles stabilized with various Ligands have been studied. Lauric acid-capped copper nanoparticles were prepared by a modified Brust–Schiffrin method. Then, Ligand exchange with an excess of different capping agents was performed. Oxidation and stability were studied by UV–vis, XRD, and TEM. Alkanethiols and oleic acid were found to improve air stability. The oxidation resistance of thiol-capped copper nanoparticles was found to increase with the chain length of the thiol. However, excess thiol caused etching of the particles under nitrogen. With oleic acid no etching was observed under nitrogen. After oxidation, no traces of the Ligand-exchanged particles were found, suggesting their dissolution due to excess Ligand. Oleic acid protected the particles against oxidation better than the tested thiols at large excess (Ligand–copper ratio 20:1).
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Influence of Ligand Structure on the stability and oxidation of copper nanoparticles
Journal of Colloid and Interface Science, 2008Co-Authors: Petri Kanninen, Juha Merta, Christoffer Johans, Kyösti KontturiAbstract:The stability and oxidation of copper nanoparticles stabilized with various Ligands have been studied. Lauric acid-capped copper nanoparticles were prepared by a modified Brust-Schiffrin method. Then, Ligand exchange with an excess of different capping agents was performed. Oxidation and stability were studied by UV-vis, XRD, and TEM. Alkanethiols and oleic acid were found to improve air stability. The oxidation resistance of thiol-capped copper nanoparticles was found to increase with the chain length of the thiol. However, excess thiol caused etching of the particles under nitrogen. With oleic acid no etching was observed under nitrogen. After oxidation, no traces of the Ligand-exchanged particles were found, suggesting their dissolution due to excess Ligand. Oleic acid protected the particles against oxidation better than the tested thiols at large excess (Ligand-copper ratio 20:1). © 2007 Elsevier Inc. All rights reserved.
Zhengzhong Shao - One of the best experts on this subject based on the ideXlab platform.
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silicon nanoparticles with surface nitrogen 90 quantum yield with narrow luminescence bandwidth and the Ligand Structure based energy law
ACS Nano, 2016Co-Authors: Qi Li, Meng Zhou, Hadi Abroshan, Jingchun Huang, Nathaniel L Rosi, Zhengzhong ShaoAbstract:Silicon nanoparticles (NPs) have been widely accepted as an alternative material for typical quantum dots and commercial organic dyes in light-emitting and bioimaging applications owing to silicon’s intrinsic merits of least toxicity, low cost, and high abundance. However, to date, how to improve Si nanoparticle photoluminescence (PL) performance (such as ultrahigh quantum yield, sharp emission peak, high stability) is still a major issue. Herein, we report surface nitrogen-capped Si NPs with PL quantum yield up to 90% and narrow PL bandwidth (full width at half-maximum (fwhm) ≈ 40 nm), which can compete with commercial dyes and typical quantum dots. Comprehensive studies have been conducted to unveil the influence of particle size, Structure, and amount of surface Ligand on the PL of Si NPs. Especially, a general Ligand-Structure-based PL energy law for surface nitrogen-capped Si NPs is identified in both experimental and theoretical analyses, and the underlying PL mechanisms are further discussed.
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Silicon Nanoparticles with Surface Nitrogen: 90% Quantum Yield with Narrow Luminescence Bandwidth and the Ligand Structure Based Energy Law.
ACS Nano, 2016Co-Authors: Qi Li, Meng Zhou, Hadi Abroshan, Jingchun Huang, Nathaniel L Rosi, Zhengzhong ShaoAbstract:Silicon nanoparticles (NPs) have been widely accepted as an alternative material for typical quantum dots and commercial organic dyes in light-emitting and bioimaging applications owing to silicon’s intrinsic merits of least toxicity, low cost, and high abundance. However, to date, how to improve Si nanoparticle photoluminescence (PL) performance (such as ultrahigh quantum yield, sharp emission peak, high stability) is still a major issue. Herein, we report surface nitrogen-capped Si NPs with PL quantum yield up to 90% and narrow PL bandwidth (full width at half-maximum (fwhm) ≈ 40 nm), which can compete with commercial dyes and typical quantum dots. Comprehensive studies have been conducted to unveil the influence of particle size, Structure, and amount of surface Ligand on the PL of Si NPs. Especially, a general Ligand-Structure-based PL energy law for surface nitrogen-capped Si NPs is identified in both experimental and theoretical analyses, and the underlying PL mechanisms are further discussed.
Hidetoshi Noda - One of the best experts on this subject based on the ideXlab platform.
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synthesis of chemically and configurationally stable monofluoro acylboronates effect of Ligand Structure on their formation properties and reactivities
ChemInform, 2015Co-Authors: Hidetoshi Noda, Jeffrey W BodeAbstract:The reaction of a range of bidentate N-containing Ligands with acyltrifluoroborates is examined for the formation of novel monofluoro acylborates which are stable to air and water.
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synthesis of chemically and configurationally stable monofluoro acylboronates effect of Ligand Structure on their formation properties and reactivities
Journal of the American Chemical Society, 2015Co-Authors: Hidetoshi Noda, Jeffrey W BodeAbstract:The recent disclosures of two classes of acylborons, potassium acyltrifluoroborates (KATs) and N-methyliminodiacetyl (MIDA) acylboronates, demonstrated that certain acylboron species can be both remarkably stable and uniquely reactive. Here we report new classes of Ligands for acylboronates that have a significant influence on the formation, properties, and reactivities of acylboronates. Our systematic investigations identified a class of neutral, monofluoroboronates that can be prepared in a one step, gram-scale fashion from readily accessible KATs. These monofluoroboronates are stable to air, moisture, and silica gel chromatography and can be easily handled without any special precautions. X-ray crystallography, NMR spectroscopy, and HPLC studies showed that they are tetravalent, configurationally stable B-chiral acylboronates. Significantly, the Ligands on the boronate allow for fine-tuning of the properties and reactivity of acylboronates. In amide-forming ligation with hydroxylamines under aqueous co...