G. T. Fechner: In Memoriam (1801-1887)

Marshall, Marilyn E.

doi:10.1037/e553832006-002

Cited by 9 publications

(13 citation statements)

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“…Compound identification was carried out by comparative TLC/OPLC with authentic samples and/or chemical ionization mass spectrometry (C1-MS) on extracted chromatographic zones. Many of the 14 phorbol diesters detected in croton resin in this study were found to be pure, including the commercially important standard tumor-promoting agent, l2-O-tetradecanoylphorbol-13-acetate (TPA) (7). Some of the chromatographic zones contained two phorbol diesters which were closely comparable in molecular weight, i.e., compounds 3 and 4,9 and 10, and!!…”

Section: Resultsmentioning

confidence: 69%

“…Louis, Missouri, U.S.A. Authentic samples of the following phorbol 12, 13-diesters obtained in this laboratory in previous investigations on croton oil (7,8,9,14) were: 12-O-tiglylphorbol-13-acetate (1), 12-0tiglylphorbol-13-isobutyrate (2), 12-O-(2-methyl)-butyrylphorbol-13isobutyrate (3), 12-O-tiglylphorbol-13-(2-methyl)-butyrate (4), 12-0decanoylphorbol-13-acetate (5), 12-O-dodecanoylphorbol-13-acetate (6), 12-O-tetradecanoylphorbol-13-acetate (7), 12-0-hexadecanoylphorbol-13-acetate (8), 12-O-acetylphorbol-13-decanoate (9), and 12-O-(2-methyl)-butyrylphorbol-13-decanoate (13). Compounds 5-8 and 9 and 13 represent Hecker's croton oil fractors A1-A4 and B2 and B7, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…(Anspec, Warrenville, Illinois, U.S.A.), packed with silica gel H for TLC (Merck, Darmstadt, West Germany); Mobile phase: Chloroform-acetone (5: 1); Flow rate: 3.0 mI/mm. Sample: Croton oil (20 g) was dissolved in n-hexane and partitioned with methanol-water, as described previously (7), to afford 1.12 g of a hydrophilic residue that has been termed "croton resin" by other workers (9,13). An 800mg portion of the croton resin was dissolved in 2 ml of mobile phase.…”

Section: Low-pressure Liquid Chromatographymentioning

confidence: 99%

“…The Hecker group isolated eleven phorbol diesters from croton oil that were extractable into hydrophilic solvents, as well as a further three such compounds obtained after the partial hydrolysis of a mixture of phorbol triesters present in a lipophilic extract of the plant (1,3). In this laboratory, we have recently fully characterized an additional seven phorbol esters and four 4-deoxy-4ct-phorbol esters as constituents of croton oil (7).…”

Section: Introductionmentioning

confidence: 99%

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Phorbol Diester Constituents of Croton Oil: Separation by Two-Dimensional TLC and Rapid Purification Utilizing Reversed-Phase Overpressure Layer Chromatography (RP-OPLC)

Erdelmeier¹,

Leeuwen²,

Kinghorn³

1988

Planta Med

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Fourteen known phorbol diester constituents of Croton tighum L. seed oil (croton oil) have been separated by a two-dimensional thin-layer chromatographic (2D-TLC) technique using different sorbent layers on the same plate. After a preliminary purification step using low-pressure liquid chromatography, reversed-phase overpressure liquid chromatography (RP-OPLC) has been shown to be potentially useful for the rapid preparative purification of these toxins. The identity of the major croton oil phorbol diesters was established by cochromatography with authentic compounds and/or by off-line chemical ionization mass spectrometry. The standard tumor-promoting agent, 12-O-tetradecanoylphorbol-13-acetate, was obtained free from impurities as a result of the application of both the 2D-TLC and liquid chromatography-RP-OPLC procedures.

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Section: Resultsmentioning

confidence: 69%

Section: Methodsmentioning

confidence: 99%

Section: Low-pressure Liquid Chromatographymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Phorbol Diester Constituents of Croton Oil: Separation by Two-Dimensional TLC and Rapid Purification Utilizing Reversed-Phase Overpressure Layer Chromatography (RP-OPLC)

Erdelmeier¹,

Leeuwen²,

Kinghorn³

1988

Planta Med

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“…Nevertheless, excellent results can be obtained with more traditional electrophoretic methods. Thus, Lapin et al [87] have described an economic method of SDS-PAGE for hospital laboratory use (based upon precast gels and overnight staining in CBB/perchloric acid) and we have recommended a simplified SDS-PAGE method with high sample throughput and good detection of unconcentrated urine using either CBB or silver staining [88].…”

Section: Methodological Developmentsmentioning

confidence: 99%

Clinical analysis of human urinary proteins using high resolution electrophoretic methods

Marshall

Williams

1998

Electrophoresis

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The application of isoelectric focusing (IEF), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two-dimensional electrophoresis (2-DE) and capillary electrophoresis (CE) for high resolution electrophoretic analysis of human urinary proteins is reviewed. In each case, the information is tabulated chronologically with details of sample preparation, electrophoretic system, detection method and clinical application. The text includes an historical perspective of the use of each method for urinalysis and a detailed review of the application of the methods to the investigation of renal disease, renal transplantation, Bence Jones proteinuria (BJP), diabetes mellitus, cadmium toxicity, nephrolithiasis and cancers of the urogenital tract.

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³¹P and ²³Na Solid-State NMR Studies of Cation Dynamics in HT-Sodium Orthophosphate and the Solid Solutions (Na₂SO₄)_x−(Na₃PO₄)₁_-_x^†

Witschas

Eckert

1999

J. Phys. Chem. A

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The high-temperature phases of sodium orthophosphate, HT-Na3PO4, and of the solid solutions (Na2SO4) x −(Na3PO4)1 - x are characterized by their plastic crystalline state with dynamically disordered PO4 3- and SO4 2- anions and a remarkably high cation conductivity. Since HT-Na3PO4 possesses a fully occupied cation sublattice (no vacancies), it has been proposed that cation transport and anion reorientations are dynamically coupled (“paddle-wheel mechanism”). However, no direct evidence for this coupling has been reported. In the present study, the validity of this mechanism is investigated on the basis of 23Na and 31P nuclear magnetic resonance (NMR) experiments. Temperature-dependent measurements of the static 31P linewidth indicate that in the solid solutions with 0.04 ≤ x ≤ 0.25 the acceleration of sodium ionic mobility is closely correlated with the acceleration of phosphate rotational motion, associated with a second-order phase transition near 400 K. Temperature-dependent measurements of the 23Na longitudinal and transverse relaxation times have been analyzed using the theory of quadrupolar relaxation under nonextreme narrowing conditions. Consistent with theoretical predictions sizeable dynamic frequency shifts are detected. All of the data are consistently analyzed quantitatively in terms of two distinct motional processes. A low-temperature process, whose relaxation strength is independent of sample composition, is clearly accelerated by the onset of fast anion rotation occurring at the second-order phase transition temperature. In addition, a high-temperature process, which is almost absent in HT-Na3PO4 but whose importance increases with increasing sulfate content, signifies vacancy hopping. This dependence on composition is easily understood because the substitution of PO4 3- by SO4 2- generates cation vacancies. The activation energies of both processes are near 0.45 eV, and the corresponding timescales grow increasingly similar with increasing sodium sulfate content. Altogether, the results give strong evidence for a dynamic coupling between anionic reorientation and cation diffusion, supporting the concept of a paddle-wheel mechanism.

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G. T. Fechner: In Memoriam (1801-1887)

Cited by 9 publications

References 0 publications

Phorbol Diester Constituents of Croton Oil: Separation by Two-Dimensional TLC and Rapid Purification Utilizing Reversed-Phase Overpressure Layer Chromatography (RP-OPLC)

Phorbol Diester Constituents of Croton Oil: Separation by Two-Dimensional TLC and Rapid Purification Utilizing Reversed-Phase Overpressure Layer Chromatography (RP-OPLC)

Clinical analysis of human urinary proteins using high resolution electrophoretic methods

³¹P and ²³Na Solid-State NMR Studies of Cation Dynamics in HT-Sodium Orthophosphate and the Solid Solutions (Na₂SO₄)_x−(Na₃PO₄)₁_-_x^†

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G. T. Fechner: In Memoriam (1801-1887)

Cited by 9 publications

References 0 publications

Phorbol Diester Constituents of Croton Oil: Separation by Two-Dimensional TLC and Rapid Purification Utilizing Reversed-Phase Overpressure Layer Chromatography (RP-OPLC)

Phorbol Diester Constituents of Croton Oil: Separation by Two-Dimensional TLC and Rapid Purification Utilizing Reversed-Phase Overpressure Layer Chromatography (RP-OPLC)

Clinical analysis of human urinary proteins using high resolution electrophoretic methods

31P and 23Na Solid-State NMR Studies of Cation Dynamics in HT-Sodium Orthophosphate and the Solid Solutions (Na2SO4)x−(Na3PO4)1-x†

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Product

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About

³¹P and ²³Na Solid-State NMR Studies of Cation Dynamics in HT-Sodium Orthophosphate and the Solid Solutions (Na₂SO₄)_x−(Na₃PO₄)₁_-_x^†