Chromatographic study of 1-methyl-4-iminouracil

1967 ◽  
Vol 1 (5) ◽  
pp. 279-281
Author(s):  
M. M. Kaganskii ◽  
V. V. Sinitsyn
Keyword(s):  
Chromatographic Study

Gas chromatographic study of the sorption of C1-C3 alkanes on nickel catalysts

1969 ◽  
Vol 34 (9) ◽  
pp. 2652-2661
Author(s):  
L. Scháněl ◽  
P. Schneider ◽  
V. Bažant
Keyword(s):  
Nickel Catalysts ◽  
Chromatographic Study

THE INFLUENCE OF 17α-METHYL-19-NORTESTOSTERONE (M. N. T.) ON THE METABOLISM OF CORTISOL

1962 ◽  
Vol 39 (1) ◽  
pp. 22-31 ◽  
Author(s):  
A. Vermeulen ◽  
J. Ferin
Keyword(s):  
Urinary Excretion ◽  
Liver Enzyme ◽  
Chromatographic Analysis ◽  
Inactivation Rate ◽  
Chromatographic Study ◽  
List Type ◽  
Cortisol Metabolism ◽  
Enzyme Systems ◽  
Corticosterone Metabolites ◽  
Cortisol Metabolites

ABSTRACT The effect of prolonged 17α-methyl-nortestosterone (M. N. T.) administration on cortisol metabolism was studied in several patients. 1. A decreased urinary excretion of 17-hydroxycorticosteroids occurred regularly. 2. Chromatographic analysis of the urinary corticoids revealed that the decreased urinary excretion involved exclusively cortisol metabolites, whereas corticosterone metabolites were excreted at normal levels. This chromatographic study moreover showed an impairment in the conjugation of tetrahydrocorticoids. 3. Studies with 4-14C-cortisol in MNT treated patients showed increased transcortin levels, a normal cortisol pool, a reduced cortisol inactivation rate and a decreased cortisol production. 4. From these results it is concluded that the decreased 17-hydroxycorticoid excretion reflects a decreased cortisol production, at least partly secondary to a reduced cortisol-inactivation rate, which itself must be attributable either to an inhibition or a defect in the liver enzyme systems concerned in corticoid-inactivation.

Adsorption and Desorption of Tritium in Nuclear Graphite at 700°C: A Gas Chromatographic Study Using Hydrogen

2019 ◽  
Vol 205 (9) ◽  
pp. 1143-1153 ◽  
Author(s):  
Ke Deng ◽  
Mingjun Zhang ◽  
Xijun Wu ◽  
Qin Zhang ◽  
Guo Yang ◽  
...  
Keyword(s):  
Chromatographic Study ◽  
Adsorption And Desorption ◽  
Nuclear Graphite

scholarly journals Micellar Electrokinetic Chromatographic Study of the Separation of an Aromatase Inhibitor and a Tryciclic Antidepressant in the Breast Cancer Treatment

2008 ◽  
Vol 3 ◽  
pp. ACI.S939 ◽  
Author(s):  
J. Rodríguez Flores ◽  
A.M. Contento Salcedo ◽  
L. Muñoz Fernández
Keyword(s):  
Micellar Electrokinetic Chromatography ◽  
Solid Phase ◽  
Background Electrolyte ◽  
Kinetic Studies ◽  
Breast Cancer Treatment ◽  
Chromatographic Study ◽  
Optimal Conditions ◽  
Sodium Dodecylsulphate ◽  
Experimental Parameters

Micellar electrokinetic chromatography (MEKC) was investigated for the simultaneous determination of letrozole, imipramine and their metabolites in human urine samples over a concentration range of therapeutic interest. Experimental parameters such as pH of the running electrolyte, sodium dodecylsulphate (SDS) concentration, borate concentration, voltage, etc were investigated. Under optimal conditions of 25 mM SDS, 15 mM borate buffer (pH 9.2), 15% 2-propanol, as background electrolyte; 28 kV and 40 °C, as voltage and cartridge temperature, respectively; resolution between the peaks was greater than 1.7. Before the determination, a solid phase extraction (SPE) procedure with a C18 cartridge was optimized. Good linearity, accuracy, precision, robustness and ruggedness were achieved and detection limits of 12.5 ng/mL for letrozole and its metabolite and 37.5 ng/mL, were obtained for imipramine and their metabolites. Real determinations of these analytes in two patient urines were carried out. Sensitivity achieved in this method is sufficient to perform kinetic studies in humans.

Gas chromatographic study of steroids in the production of vitamin D2

1969 ◽  
Vol 3 (1) ◽  
pp. 31-32
Author(s):  
M. Ts. Yanotovskii ◽  
N. A. Bogoslovskii ◽  
E. N. Kuznetsova
Keyword(s):  
Chromatographic Study ◽  
Vitamin D2

Calmodulin and troponin C: affinity chromatographic study of divalent cation requirements for troponin I inhibitory peptide (residues 104–115), mastoparan, and fluphenazine binding

1987 ◽  
Vol 65 (11) ◽  
pp. 982-988 ◽  
Author(s):  
Jennifer E. Van Eyk ◽  
Robert S. Hodges
Keyword(s):  
Troponin I ◽  
Troponin C ◽  
Homologous Region ◽  
Affinity Column ◽  
Chromatographic Study ◽  
Inhibitory Peptide ◽  
Receptor Sites ◽  
Inhibitory Region ◽  
Correct Alignment ◽  
Correct Structure

The different conformations induced by the binding of Mg2+ or Ca2+ to troponin C (TnC) and calmodulin (CaM) results in the exposure of various interfaces with potential to bind target compounds. The interaction of TnC or CaM with three affinity columns with ligands of either the synthetic peptide of troponin I (TnI) inhibitory region (residues 104–115), mastoparan (a wasp venom peptide), or fluphenazine (a phenothiazine drug) were investigated in the presence of Mg2+ or Ca2+. TnC and CaM in the presence of either Ca2+ or Mg2+ bound to the TnI peptide 104–115. The cation specificity for this interaction firmly establishes that the TnI inhibitory region binds to the high affinity sites of TnC (most likely the N-terminal helix of site III) and presumably the homologous region of CaM. Mastoparan interacted strongly with both proteins in the presence of Ca2+ but, in the presence of Mg2+, did not bind to TnC and only bound weakly to CaM. Fluphenazine bound to TnC and CaM only in the presence of Ca2+. When the ligands interacted with either proteins there was an increase in cation affinity, such that TnC and CaM were eluted from the TnI peptide or mastoparan affinity column with 0.1 M EDTA compared with the 0.01 M EDTA required to elute the proteins from the fluphenazine column. The interaction of these ligands with their receptor sites on TnC and CaM require a specific and spatially correct alignment of hydrophobic and negatively charged residues on these proteins. In the case of the TnI peptide, which represents a naturally occurring target protein for TnC, Mg2+ and Ca2+ can induce the correct structure in TnC or CaM for interaction, while only Ca2+ can induce the correct structure for mastoparan or fluophenazine binding.

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