14169-76-7Relevant academic research and scientific papers
CHOLESTEROL CONVERSION TO Δ4-CHOLESTENONE BY CHOLESTEROL OXIDASE IN POLYPHASIC SYSTEMS : EXTENSION TO THE SELECTIVE OXIDATION OF 7Β-HYDROXYCHOLESTEROL
Lee, Kang Min,Biellmann, Jean-Francois
, p. 1135 - 1140 (1988)
The preparative use of cholesterol oxidase has been extended to polyphasic systems.The enzyme is active in microemulsions with the organic phase composed of mixtures of cyclohexane and chloroform.The kinetic data for oxidation of 7α- and 7β-hydroxycholesterol in microemulsion with the enzyme from Streptomyces are similar to those of cholesterol.The cholesterol oxidase is active in the two phase system aqueous buffer - butyl acetate and preparative enzymic conversion of 7β-hydroxycholesterol to Δ4-7β-hydroxycholestenone was performed in this medium.The enzymic conversion of cholesterol to Δ4-cholestenone was also performed in two liquis-solid systems, in buffer with cholesterol adsorbed on silica gel and in organic medium with cholesterol oxidase and catalase entrapped in Chromosorb.
7 α-hydroxy-3-oxo-4-cholestenoic acid in cerebrospinal fl uid refl ects the integrity of the blood-brain barrier
Saeed, Ahmed,Floris, Federico,Andersson, Ulla,Pikuleva, Irina,LOevgren-Sandblom, Anita,Bjerke, Maria,Paucar, Martin,Wallin, Anders,Svenningsson, Per,BjOerkhem, Ingemar
, p. 313 - 318 (2014)
Abstract There is a continuous fl ux of the oxysterol 27- hydroxycholesterol (27-OHC) from the circulation across the blood-brain barrier (BBB) into the brain. The major metabolite of 27-OHC in the brain is 7 α -hydroxy-3-oxo-4- cholestenoic acid (7-HOCA). We confirm a recent report describing the presence of this metabolite in cerebrospinal fl uid (CSF) at a relatively high concentration. A simple and accurate method was developed for assay of 7-HOCA in CSF based on isotope dilution-mass spectrometry and use of 2 H 4 -labeled internal standard. The concentration of this metabolite was found to be markedly increased in CSF from patients with a dysfunctional BBB. There was a high correlation between the levels of 7-HOCA in CSF and the CSF/serum albumin ratio. The concentration of 7-HOCA in CSF was not significantly affected by neurodegeneration. Our findings suggest that 7-HOCA could be used as a diagnostic marker for conditions with a dysfunctional BBB. -Saeed, A., F. Floris, U. Andersson, I. Pikuleva, A. LOevgren-Sandblom, M. Bjerke, M. Paucar, A. Wallin, P. Svenningsson, and I. BjOerkhem. 7 α -hydroxy-3-oxo-4-cholestenoic acid in cerebrospinal fl uid refl ects the integrity of the blood-brain barrier. Copyright
