The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Yu-qi Feng - One of the best experts on this subject based on the ideXlab platform.
-
Simultaneous Determination of Multiclass Phytohormones in Submilligram Plant Samples by One-Pot Multifunctional Derivatization-Assisted Liquid Chromatography–Tandem Mass Spectrometry
Analytical chemistry, 2019Co-Authors: Wen-jing Cai, Wei Wang, Meng-xiang Sun, Yu-qi FengAbstract:Phytohormones play crucial roles in every aspect of plant life, and their regulatory functions rely on complex crosstalk networks among the different classes of phytohormones in an antagonistic or synergistic manner. Therefore, the simultaneous determination of multiclass phytohormones is important for studies of phytohormone functions and networks. However, due to the heterogeneity of the sensitivity resulting from structural diversity and the low content in the plant samples, simultaneous determination of multiclass phytohormones is challenging, especially in very tiny plant tissues or organs. Here, we describe a novel method for the simultaneous determination of 31 phytohormones from different classes in a single run. This uses a one-pot multifunctional derivatization coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS). N, N-Diethyl ethylenediamine (DEED) and 2-methyl-4-phenylaminomethyl-Benzeneboronic Acid (2-methy-4-PAMBA) were used for derivatization of carboxylated phytohormones and brassinosteroids (BRs), respectively, to simultaneously improve detection sensitivities of carboxylated phytohormones and BRs. The method was fully validated for the 31 targeted phytohormones and could quantify multiclass endogenous phytohormones in small amounts of fresh plant samples (0.02-5 mg, FW). Finally, we used this method to investigate the spatial-temporal distribution of multiple phytohormones in reproductive organs of a single flower of Arabidopsis thaliana for the first time. This method could be a powerful auxiliary tool for studies of phytohormone functions and regulatory networks.
-
Simultaneous Determination of Multiclass Phytohormones in Submilligram Plant Samples by One-Pot Multifunctional Derivatization-Assisted Liquid Chromatography–Tandem Mass Spectrometry
2019Co-Authors: Wen-jing Cai, Wei Wang, Meng-xiang Sun, Yu-qi FengAbstract:Phytohormones play crucial roles in every aspect of plant life, and their regulatory functions rely on complex crosstalk networks among the different classes of phytohormones in an antagonistic or synergistic manner. Therefore, the simultaneous determination of multiclass phytohormones is important for studies of phytohormone functions and networks. However, due to the heterogeneity of the sensitivity resulting from structural diversity and the low content in the plant samples, simultaneous determination of multiclass phytohormones is challenging, especially in very tiny plant tissues or organs. Here, we describe a novel method for the simultaneous determination of 31 phytohormones from different classes in a single run. This uses a one-pot multifunctional derivatization coupled to liquid chromatography–tandem mass spectrometry (LC–MS/MS). N,N-Diethyl ethylenediamine (DEED) and 2-methyl-4-phenylaminomethyl-Benzeneboronic Acid (2-methy-4-PAMBA) were used for derivatization of carboxylated phytohormones and brassinosteroids (BRs), respectively, to simultaneously improve detection sensitivities of carboxylated phytohormones and BRs. The method was fully validated for the 31 targeted phytohormones and could quantify multiclass endogenous phytohormones in small amounts of fresh plant samples (0.02–5 mg, FW). Finally, we used this method to investigate the spatial-temporal distribution of multiple phytohormones in reproductive organs of a single flower of Arabidopsis thaliana for the first time. This method could be a powerful auxiliary tool for studies of phytohormone functions and regulatory networks
-
Profiling of potential brassinosteroids in different tissues of rape flower by stable isotope labeling - liquid chromatography/mass spectrometry analysis.
Analytica chimica acta, 2017Co-Authors: Ya-li Bai, Wen-jing Cai, Jun Ding, Bi-feng Yuan, Yu-qi FengAbstract:Brassinosteroids (BRs) play crucial roles in a variety of physiological processes in plants. The full elucidation of the functions of RBs relies on sensitive detection and accurate measurement of BRs in plants. However, the identification and quantification of BRs are challenging due to their low abundance as well as poor ionization efficiencies during mass spectrometry-based analysis. Herein, we developed a highly sensitive and selective strategy for profiling potential BRs in plants by stable isotope labeling liquid chromatography multiple reaction monitoring scan mass spectrometry (SIL-LC-MRM-MS) analysis. In the strategy, we used a pair of stable isotope labeling reagents 4-phenylaminomethyl-Benzeneboronic Acid (4-PAMBA) and d5-4-phenylaminomethyl-Benzeneboronic Acid (4-PAMBA-d5) that can react with C22-C23 cis-diol on BRs for profiling potential BRs in plant tissues. The 4-PAMBA and 4-PAMBA-d5 labeled BRs could generate two characteristic neutral loss under collision induced dissociation (CID), respectively, which is used to establish the MRM-based detection and screening. The precursor ions of BRs labeled with 4-PAMBA and 4-PAMBA-d5 were set according to the reported structures of BRs, and the corresponding product ions were predicted by subtracting the lost neutral loss. In this respect, corresponding precursor ions and product ions in MRM transitions are formed. The peak pairs with a fixed mass difference, similar retention times and intensities were assigned as potential BRs. Using the developed SIL-LC-MRM-MS strategy, we successfully found 13 potential BR in different tissues of rape flower. Taken together, the SIL-LC-MRM-MS analytical strategy is promising for profiling potential BRs as well as other compounds that have the same functional moiety from complex biological samples.
James H. Clark - One of the best experts on this subject based on the ideXlab platform.
-
Structure-activity relationship between some novel silica supported palladium catalysts: a study of the Suzuki reaction
Journal of Molecular Catalysis A-chemical, 2004Co-Authors: Satya Paul, James H. ClarkAbstract:Abstract A series of novel silica supported palladium catalysts bearing N–N, N–S and N–O chelating ligands have been prepared by the following reactions—(a) synthesis of 3-aminopropylsilica from activated silica and 3-aminopropyl(trimethoxy)silane; (b) synthesis of Schiff-bases from 3-aminopropylsilica and 2-acetylpyridine, 2-pyridinecarboxaldehyde, 2-thiophenecarboxaldehyde, 2-furancarboxaldehyde, 2-acetylfuran, 2-hydroxyacetopheneone, 2-aminoacetopheneone and 2-pyrrolecarboxaldehyde; (c) reaction of Schiff-bases with palladium acetate to obtain silica supported palladium catalysts. The catalysts were characterized by STA, BET, DRIFT and X-ray photoelectron spectroscopy (XPS). X-ray photoelectron spectroscopy has been found to be a useful tool for establishing the structure-activity relationship between supported palladium catalysts with different chelating atoms using Suzuki reaction as an example. The catalysts with lower binding energy for palladium in comparison to palladium acetate are more active than those with higher binding energies. The activity of the catalysts was compared on the basis of rate constants in the Suzuki reaction between bromobenzene and Benzeneboronic Acid using anhydrous potassium carbonate as base and o -xylene as solvent.
-
A highly active and reusable heterogeneous catalyst for the Suzuki reaction: synthesis of biaryls and polyaryls
Green Chemistry, 2003Co-Authors: Satya Paul, James H. ClarkAbstract:A novel silica supported palladium catalyst has been prepared and investigated for the Suzuki cross-coupling reaction between aryl bromides and Benzeneboronic Acid in the presence of K2CO3 as base and o-xylene as solvent. The key features of the catalyst include rapid reactions with 100% conversion of aryl bromides, excellent catalyst recyclability and total stability under the reaction conditions (passes hot filtration test successfully). No change in the catalyst structure has been observed on the basis of surface analysis and simultaneous thermal analysis even after the 7th use. The catalyst can be used for consecutive Suzuki reactions in a single step and hence successfully applied to the synthesis of polyaryls.
Maurice Santelli - One of the best experts on this subject based on the ideXlab platform.
-
Palladium–tetraphosphine catalysed cross coupling of aryl bromides with arylboronic Acids: remarkable influence of the nature of the ligand
Chemical Communications, 2001Co-Authors: Marie Feuerstein, Dorothée Laurenti, Céline Bougeant, Henri Doucet, Maurice SantelliAbstract:The cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane –[PdCl(C3H5)]2 system catalyses the cross coupling of aryl bromides with arylboronic Acids with very high substrate–catalyst ratios in good yields; a turnover number of 28000000 can be obtained for the addition of 4-bromobenzophenone to Benzeneboronic Acid in the presence of this catalyst.
-
Tetraphosphine/palladium-catalysed Suzuki cross-coupling with sterically hindered aryl bromides and arylboronic Acids
Tetrahedron Letters, 2001Co-Authors: Marie Feuerstein, Henri Doucet, Maurice SantelliAbstract:cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C3H5)]2 system efficiently catalyses the Suzuki cross-coupling of sterically hindered substrates. Very high turnover numbers can be obtained for the coupling of sterically hindered aryl bromides with Benzeneboronic Acid or for the coupling of bromobenzene with sterically hindered arylboronic Acids. On the other hand the formation of tri-ortho-substituted biaryl adducts requires higher catalyst loading.
Satya Paul - One of the best experts on this subject based on the ideXlab platform.
-
Structure-activity relationship between some novel silica supported palladium catalysts: a study of the Suzuki reaction
Journal of Molecular Catalysis A-chemical, 2004Co-Authors: Satya Paul, James H. ClarkAbstract:Abstract A series of novel silica supported palladium catalysts bearing N–N, N–S and N–O chelating ligands have been prepared by the following reactions—(a) synthesis of 3-aminopropylsilica from activated silica and 3-aminopropyl(trimethoxy)silane; (b) synthesis of Schiff-bases from 3-aminopropylsilica and 2-acetylpyridine, 2-pyridinecarboxaldehyde, 2-thiophenecarboxaldehyde, 2-furancarboxaldehyde, 2-acetylfuran, 2-hydroxyacetopheneone, 2-aminoacetopheneone and 2-pyrrolecarboxaldehyde; (c) reaction of Schiff-bases with palladium acetate to obtain silica supported palladium catalysts. The catalysts were characterized by STA, BET, DRIFT and X-ray photoelectron spectroscopy (XPS). X-ray photoelectron spectroscopy has been found to be a useful tool for establishing the structure-activity relationship between supported palladium catalysts with different chelating atoms using Suzuki reaction as an example. The catalysts with lower binding energy for palladium in comparison to palladium acetate are more active than those with higher binding energies. The activity of the catalysts was compared on the basis of rate constants in the Suzuki reaction between bromobenzene and Benzeneboronic Acid using anhydrous potassium carbonate as base and o -xylene as solvent.
-
A highly active and reusable heterogeneous catalyst for the Suzuki reaction: synthesis of biaryls and polyaryls
Green Chemistry, 2003Co-Authors: Satya Paul, James H. ClarkAbstract:A novel silica supported palladium catalyst has been prepared and investigated for the Suzuki cross-coupling reaction between aryl bromides and Benzeneboronic Acid in the presence of K2CO3 as base and o-xylene as solvent. The key features of the catalyst include rapid reactions with 100% conversion of aryl bromides, excellent catalyst recyclability and total stability under the reaction conditions (passes hot filtration test successfully). No change in the catalyst structure has been observed on the basis of surface analysis and simultaneous thermal analysis even after the 7th use. The catalyst can be used for consecutive Suzuki reactions in a single step and hence successfully applied to the synthesis of polyaryls.
Wen-jing Cai - One of the best experts on this subject based on the ideXlab platform.
-
Simultaneous Determination of Multiclass Phytohormones in Submilligram Plant Samples by One-Pot Multifunctional Derivatization-Assisted Liquid Chromatography–Tandem Mass Spectrometry
Analytical chemistry, 2019Co-Authors: Wen-jing Cai, Wei Wang, Meng-xiang Sun, Yu-qi FengAbstract:Phytohormones play crucial roles in every aspect of plant life, and their regulatory functions rely on complex crosstalk networks among the different classes of phytohormones in an antagonistic or synergistic manner. Therefore, the simultaneous determination of multiclass phytohormones is important for studies of phytohormone functions and networks. However, due to the heterogeneity of the sensitivity resulting from structural diversity and the low content in the plant samples, simultaneous determination of multiclass phytohormones is challenging, especially in very tiny plant tissues or organs. Here, we describe a novel method for the simultaneous determination of 31 phytohormones from different classes in a single run. This uses a one-pot multifunctional derivatization coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS). N, N-Diethyl ethylenediamine (DEED) and 2-methyl-4-phenylaminomethyl-Benzeneboronic Acid (2-methy-4-PAMBA) were used for derivatization of carboxylated phytohormones and brassinosteroids (BRs), respectively, to simultaneously improve detection sensitivities of carboxylated phytohormones and BRs. The method was fully validated for the 31 targeted phytohormones and could quantify multiclass endogenous phytohormones in small amounts of fresh plant samples (0.02-5 mg, FW). Finally, we used this method to investigate the spatial-temporal distribution of multiple phytohormones in reproductive organs of a single flower of Arabidopsis thaliana for the first time. This method could be a powerful auxiliary tool for studies of phytohormone functions and regulatory networks.
-
Simultaneous Determination of Multiclass Phytohormones in Submilligram Plant Samples by One-Pot Multifunctional Derivatization-Assisted Liquid Chromatography–Tandem Mass Spectrometry
2019Co-Authors: Wen-jing Cai, Wei Wang, Meng-xiang Sun, Yu-qi FengAbstract:Phytohormones play crucial roles in every aspect of plant life, and their regulatory functions rely on complex crosstalk networks among the different classes of phytohormones in an antagonistic or synergistic manner. Therefore, the simultaneous determination of multiclass phytohormones is important for studies of phytohormone functions and networks. However, due to the heterogeneity of the sensitivity resulting from structural diversity and the low content in the plant samples, simultaneous determination of multiclass phytohormones is challenging, especially in very tiny plant tissues or organs. Here, we describe a novel method for the simultaneous determination of 31 phytohormones from different classes in a single run. This uses a one-pot multifunctional derivatization coupled to liquid chromatography–tandem mass spectrometry (LC–MS/MS). N,N-Diethyl ethylenediamine (DEED) and 2-methyl-4-phenylaminomethyl-Benzeneboronic Acid (2-methy-4-PAMBA) were used for derivatization of carboxylated phytohormones and brassinosteroids (BRs), respectively, to simultaneously improve detection sensitivities of carboxylated phytohormones and BRs. The method was fully validated for the 31 targeted phytohormones and could quantify multiclass endogenous phytohormones in small amounts of fresh plant samples (0.02–5 mg, FW). Finally, we used this method to investigate the spatial-temporal distribution of multiple phytohormones in reproductive organs of a single flower of Arabidopsis thaliana for the first time. This method could be a powerful auxiliary tool for studies of phytohormone functions and regulatory networks
-
Profiling of potential brassinosteroids in different tissues of rape flower by stable isotope labeling - liquid chromatography/mass spectrometry analysis.
Analytica chimica acta, 2017Co-Authors: Ya-li Bai, Wen-jing Cai, Jun Ding, Bi-feng Yuan, Yu-qi FengAbstract:Brassinosteroids (BRs) play crucial roles in a variety of physiological processes in plants. The full elucidation of the functions of RBs relies on sensitive detection and accurate measurement of BRs in plants. However, the identification and quantification of BRs are challenging due to their low abundance as well as poor ionization efficiencies during mass spectrometry-based analysis. Herein, we developed a highly sensitive and selective strategy for profiling potential BRs in plants by stable isotope labeling liquid chromatography multiple reaction monitoring scan mass spectrometry (SIL-LC-MRM-MS) analysis. In the strategy, we used a pair of stable isotope labeling reagents 4-phenylaminomethyl-Benzeneboronic Acid (4-PAMBA) and d5-4-phenylaminomethyl-Benzeneboronic Acid (4-PAMBA-d5) that can react with C22-C23 cis-diol on BRs for profiling potential BRs in plant tissues. The 4-PAMBA and 4-PAMBA-d5 labeled BRs could generate two characteristic neutral loss under collision induced dissociation (CID), respectively, which is used to establish the MRM-based detection and screening. The precursor ions of BRs labeled with 4-PAMBA and 4-PAMBA-d5 were set according to the reported structures of BRs, and the corresponding product ions were predicted by subtracting the lost neutral loss. In this respect, corresponding precursor ions and product ions in MRM transitions are formed. The peak pairs with a fixed mass difference, similar retention times and intensities were assigned as potential BRs. Using the developed SIL-LC-MRM-MS strategy, we successfully found 13 potential BR in different tissues of rape flower. Taken together, the SIL-LC-MRM-MS analytical strategy is promising for profiling potential BRs as well as other compounds that have the same functional moiety from complex biological samples.