Concerning the role of 24,25-dihydrolanosterol and lanostanol in sterol biosynthesis by cultured cells
- Russell Research Center, USDA, Athens, GA (USA)
Rat hepatoma cells (H4-II-E-C3) efficiently converted a dietary supplement of (2-{sup 3}H)24,25-dihydrolanosterol (1) to ({sup 3}H)cholesterol while (2-{sup 3}H)lanostanol 4,4,14 alpha-trimethylcholestanol (2) was recovered from the cells without apparent transformation, although it was esterified and induced an accumulation of lanosterol. A comparison of the chromatographic (TLC, GLC and HPLC), spectral (MS and 1H-NMR) and physical properties of 1 and 2 is given for the first time. The inability to detect 2 in nature coupled with our findings that 1 but not 2 is metabolized to cholesterol by H4 cells is interpreted to imply that the biosynthetic inclusion of the delta 8(9)-bond during the cyclization process of squalene-oxide to a tetracyclic product is an evolutionary adaptation selected for because the olefinic linkage is structually important in the subsequent conversion of lanosterol and its stereoisomers, e.g., cycloartenol, to delta 5-sterols.
- OSTI ID:
- 5227442
- Journal Information:
- Steroids; (USA), Vol. 53:3-5; ISSN 0039-128X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHOLESTEROL
BIOSYNTHESIS
STEROLS
METABOLISM
CELL CULTURES
ESTERIFICATION
LIQUID COLUMN CHROMATOGRAPHY
MASS SPECTROSCOPY
NUCLEAR MAGNETIC RESONANCE
PROTONS
RATS
THIN-LAYER CHROMATOGRAPHY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TUMOR CELLS
ANIMAL CELLS
ANIMALS
BARYONS
CHEMICAL REACTIONS
CHROMATOGRAPHY
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
MAGNETIC RESONANCE
MAMMALS
NUCLEONS
ORGANIC COMPOUNDS
RESONANCE
RODENTS
SEPARATION PROCESSES
SPECTROSCOPY
STEROIDS
SYNTHESIS
VERTEBRATES
550501* - Metabolism- Tracer Techniques