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Jack D Henion - One of the best experts on this subject based on the ideXlab platform.

  • determination of carbofuran by online immunoaffinity chromatography with coupled column liquid chromatography mass spectrometry
    1994
    Co-Authors: Geoffrey S Rule, Alexander V Mordehai, Jack D Henion
    Abstract:

    Development of a new technology for combined on-line sample preparation and analyte confirmation is presented. This technology involves the use of antibodies for trace analyte Extraction and enrichment directly from a complex matrix. The antibodies are used in columns designed for use with ordinary high-pressure liquid chromatographic equipment. The immunoaffinity columns are combined with conventional reversed-phase LC columns by use of column-switching techniques and coupled directly to an atmospheric pressure ionization quadrupole ion trap mass spectrometer equipped with a pneumatically assisted electrospray (ion spray) interface. A column of aldehyde-activated silica was used to prepare a column specific to carbofuran. This column demonstrated excellent specificity toward carbofuran and showed no binding of another, unrelated compound, fluometuron. Direct Extraction and detection of carbofuran was demonstrated at low levels (40 pg/mL) in spiked water, but the real utility of immunoaffinity chromatography (IAC) is demonstrated by the on-line Extraction and detection of carbofuran from a chemically complex, crude Potato Extract. Samples Extracted using an IAC column indicate that superior purification is obtained with IAC in comparison with samples pumped directly onto a reversed-phase trapping column. A detection limit for carbofuran of approximately 2.5 ng/g of Potato was obtained using an atmospheric pressure ionization quadrupole ion trap mass spectrometer.

  • determination of carbofuran by on line immunoaffinity chromatography with coupled column liquid chromatography mass spectrometry
    1994
    Co-Authors: Geoffrey S Rule, Alexander V Mordehai, Jack D Henion
    Abstract:

    : Development of a new technology for combined on-line sample preparation and analyte confirmation is presented. This technology involves the use of antibodies for trace analyte Extraction and enrichment directly from a complex matrix. The antibodies are used in columns designed for use with ordinary high-pressure liquid chromatographic equipment. The immunoaffinity columns are combined with conventional reversed-phase LC columns by use of column-switching techniques and coupled directly to an atmospheric pressure ionization quadrupole ion trap mass spectrometer equipped with a pneumatically assisted electrospray (ion spray) interface. A column of aldehyde-activated silica was used to prepare a column specific to carbofuran. This column demonstrated excellent specificity toward carbofuran and showed no binding of another, unrelated compound, fluometuron. Direct Extraction and detection of carbofuran was demonstrated at low levels (40 pg/mL) in spiked water, but the real utility of immunoaffinity chromatography (IAC) is demonstrated by the on-line Extraction and detection of carbofuran from a chemically complex, crude Potato Extract. Samples Extracted using an IAC column indicate that superior purification is obtained with IAC in comparison with samples pumped directly onto a reversed-phase trapping column. A detection limit for carbofuran of approximately 2.5 ng/g of Potato was obtained using an atmospheric pressure ionization quadrupole ion trap mass spectrometer.

Geoffrey S Rule - One of the best experts on this subject based on the ideXlab platform.

  • determination of carbofuran by online immunoaffinity chromatography with coupled column liquid chromatography mass spectrometry
    1994
    Co-Authors: Geoffrey S Rule, Alexander V Mordehai, Jack D Henion
    Abstract:

    Development of a new technology for combined on-line sample preparation and analyte confirmation is presented. This technology involves the use of antibodies for trace analyte Extraction and enrichment directly from a complex matrix. The antibodies are used in columns designed for use with ordinary high-pressure liquid chromatographic equipment. The immunoaffinity columns are combined with conventional reversed-phase LC columns by use of column-switching techniques and coupled directly to an atmospheric pressure ionization quadrupole ion trap mass spectrometer equipped with a pneumatically assisted electrospray (ion spray) interface. A column of aldehyde-activated silica was used to prepare a column specific to carbofuran. This column demonstrated excellent specificity toward carbofuran and showed no binding of another, unrelated compound, fluometuron. Direct Extraction and detection of carbofuran was demonstrated at low levels (40 pg/mL) in spiked water, but the real utility of immunoaffinity chromatography (IAC) is demonstrated by the on-line Extraction and detection of carbofuran from a chemically complex, crude Potato Extract. Samples Extracted using an IAC column indicate that superior purification is obtained with IAC in comparison with samples pumped directly onto a reversed-phase trapping column. A detection limit for carbofuran of approximately 2.5 ng/g of Potato was obtained using an atmospheric pressure ionization quadrupole ion trap mass spectrometer.

  • determination of carbofuran by on line immunoaffinity chromatography with coupled column liquid chromatography mass spectrometry
    1994
    Co-Authors: Geoffrey S Rule, Alexander V Mordehai, Jack D Henion
    Abstract:

    : Development of a new technology for combined on-line sample preparation and analyte confirmation is presented. This technology involves the use of antibodies for trace analyte Extraction and enrichment directly from a complex matrix. The antibodies are used in columns designed for use with ordinary high-pressure liquid chromatographic equipment. The immunoaffinity columns are combined with conventional reversed-phase LC columns by use of column-switching techniques and coupled directly to an atmospheric pressure ionization quadrupole ion trap mass spectrometer equipped with a pneumatically assisted electrospray (ion spray) interface. A column of aldehyde-activated silica was used to prepare a column specific to carbofuran. This column demonstrated excellent specificity toward carbofuran and showed no binding of another, unrelated compound, fluometuron. Direct Extraction and detection of carbofuran was demonstrated at low levels (40 pg/mL) in spiked water, but the real utility of immunoaffinity chromatography (IAC) is demonstrated by the on-line Extraction and detection of carbofuran from a chemically complex, crude Potato Extract. Samples Extracted using an IAC column indicate that superior purification is obtained with IAC in comparison with samples pumped directly onto a reversed-phase trapping column. A detection limit for carbofuran of approximately 2.5 ng/g of Potato was obtained using an atmospheric pressure ionization quadrupole ion trap mass spectrometer.

Alexander V Mordehai - One of the best experts on this subject based on the ideXlab platform.

  • determination of carbofuran by online immunoaffinity chromatography with coupled column liquid chromatography mass spectrometry
    1994
    Co-Authors: Geoffrey S Rule, Alexander V Mordehai, Jack D Henion
    Abstract:

    Development of a new technology for combined on-line sample preparation and analyte confirmation is presented. This technology involves the use of antibodies for trace analyte Extraction and enrichment directly from a complex matrix. The antibodies are used in columns designed for use with ordinary high-pressure liquid chromatographic equipment. The immunoaffinity columns are combined with conventional reversed-phase LC columns by use of column-switching techniques and coupled directly to an atmospheric pressure ionization quadrupole ion trap mass spectrometer equipped with a pneumatically assisted electrospray (ion spray) interface. A column of aldehyde-activated silica was used to prepare a column specific to carbofuran. This column demonstrated excellent specificity toward carbofuran and showed no binding of another, unrelated compound, fluometuron. Direct Extraction and detection of carbofuran was demonstrated at low levels (40 pg/mL) in spiked water, but the real utility of immunoaffinity chromatography (IAC) is demonstrated by the on-line Extraction and detection of carbofuran from a chemically complex, crude Potato Extract. Samples Extracted using an IAC column indicate that superior purification is obtained with IAC in comparison with samples pumped directly onto a reversed-phase trapping column. A detection limit for carbofuran of approximately 2.5 ng/g of Potato was obtained using an atmospheric pressure ionization quadrupole ion trap mass spectrometer.

  • determination of carbofuran by on line immunoaffinity chromatography with coupled column liquid chromatography mass spectrometry
    1994
    Co-Authors: Geoffrey S Rule, Alexander V Mordehai, Jack D Henion
    Abstract:

    : Development of a new technology for combined on-line sample preparation and analyte confirmation is presented. This technology involves the use of antibodies for trace analyte Extraction and enrichment directly from a complex matrix. The antibodies are used in columns designed for use with ordinary high-pressure liquid chromatographic equipment. The immunoaffinity columns are combined with conventional reversed-phase LC columns by use of column-switching techniques and coupled directly to an atmospheric pressure ionization quadrupole ion trap mass spectrometer equipped with a pneumatically assisted electrospray (ion spray) interface. A column of aldehyde-activated silica was used to prepare a column specific to carbofuran. This column demonstrated excellent specificity toward carbofuran and showed no binding of another, unrelated compound, fluometuron. Direct Extraction and detection of carbofuran was demonstrated at low levels (40 pg/mL) in spiked water, but the real utility of immunoaffinity chromatography (IAC) is demonstrated by the on-line Extraction and detection of carbofuran from a chemically complex, crude Potato Extract. Samples Extracted using an IAC column indicate that superior purification is obtained with IAC in comparison with samples pumped directly onto a reversed-phase trapping column. A detection limit for carbofuran of approximately 2.5 ng/g of Potato was obtained using an atmospheric pressure ionization quadrupole ion trap mass spectrometer.

Hiroshi Hara - One of the best experts on this subject based on the ideXlab platform.

  • suppressive effect on food intake of a Potato Extract potein involving cholecystokinin release in rats
    2012
    Co-Authors: Wenya Chen, Tohru Hira, Shingo Nakajima, Hiroshi Tomozawa, Masahito Tsubata, Kazuya Yamaguchi, Hiroshi Hara
    Abstract:

    We have recently reported that oral gavage of a Potato Extract (Potein®) suppressed the food intake in rats. The satiating effect of the Potato Extract was compared in the present study to other protein sources, and the involvement of endogenous cholecystokinin (CCK) secretion was examined. Food consumption was measured in 18-h fasted rats after oral gavage of the Potato Extract or other protein sources. The CCK-releasing activity of the Potato Extract was then examined in anesthetized rats with a portal cannula. Oral gavage of the Potato Extract reduced the food intake in the rats, the effect being greater than with casein and a soybean β-conglycinin hydrolysate. The suppressive effect on appetite of the Potato Extract was attenuated by treating with a CCK-receptor antagonist (devazepide). The portal CCK concentration was increased after a duodenal administration of the Potato Extract to anesthetized rats. These results indicate that the Potato Extract suppressed the food intake in rats through CCK secretion.

  • Potato Extract potein suppresses food intake in rats through inhibition of luminal trypsin activity and direct stimulation of cholecystokinin secretion from enteroendocrine cells
    2011
    Co-Authors: Shingo Nakajima, Tohru Hira, Masahito Tsubata, Kinya Takagaki, Hiroshi Hara
    Abstract:

    Dietary proteins and trypsin inhibitors are known to stimulate the secretion of the satiety hormone cholecystokinin (CCK). A Potato Extract (Potein) contains 60% carbohydrate and 20% protein including trypsin inhibitory proteins. In this study, we examined whether Potein suppresses food intake in rats and whether it directly stimulates CCK secretion in enteroendocrine cells. In fasted rats, food consumption was measured up to 6 h after the oral administration of Potein or soybean trypsin inhibitor (SBTI). CCK-releasing activities of Potein and SBTI were examined in the murine CCK-producing cell line STC-1. Potein inhibited the trypsin activity in vitro with a potency 20-fold lower than that of SBTI. Oral administration of Potein dose-dependently suppressed food intake for 1–6 h. Potein, but not the SBTI, dose-dependently induced CCK secretion in STC-1 cells. These results suggest that Potein suppresses food intake through the CCK secretion induced by direct stimulation on enteroendocrine cells and through...

Jiuliang Zhang - One of the best experts on this subject based on the ideXlab platform.

  • screening of effective xanthine oxidase inhibitors in dietary anthocyanins from purple sweet Potato ipomoea batatas l cultivar eshu no 8 and deciphering of the underlying mechanisms in vitro
    2017
    Co-Authors: Zicheng Zhang, Hongbin Wang, Qing Zhou, Jiahao Wen, Jiuliang Zhang
    Abstract:

    Abstract This study was aimed to screen the effective xanthine oxidase (XO) inhibitors in dietary anthocyanins from purple sweet Potato and decipher the underlying mechanisms in vitro . Inhibition kinetics demonstrated that anthocyanin-rich purple sweet Potato Extract (APSPE) has reversible and mixed inhibitory effect on XO. Among the four fractions purified from APSPE, the fraction with highly-acylated anthocyanins showed the most powerful inhibition on XO. Molecular docking results suggested that the inhibition mechanism is the insertion of anthocyanins into the hydrophobic pocket of XO by interacting with some amino acid residues. Fluorescence and CD spectroscopy results showed that the formation of anthocyanin-XO complex is the possible quenching mechanism, which changes the secondary structure of XO. The reaction is entropy-driven and endothermic, with hydrophobic interaction being the major driving force. This study indicates that the highly-acylated dietary anthocyanins of purple sweet Potato would be a promising XO inhibitor in clinical treatment.