Synthesis of 24S and 24R-hydroxy-(24-/sup 3/H) vitamin D/sub 3/ and their metabolism in rachitic rats

Journal Article · Thu Jan 01 04:00:00 EST 1976 · Arch. Biochem. Biophys.; (United States)

DOI:https://doi.org/10.1016/0003-9861(76)90473-2· OSTI ID:6790160

Tanaka, Y ^[1]; DeLuca, H F; Akaiwa, A; Morisaki, M; Ikekawa, N

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1. Univ. of Wisconsin, Madison

An epimeric mixture of 24-hydroxy-(24-/sup 3/H) vitamin D/sub 3/ was synthesized by the reduction of 24-ketovitamin D/sub 3/ by sodium borotritide. The epimeric mixture was converted to the trimethylsilylether derivatives and subjected to high-pressure liquid chromatography using silica gel columns to separate the 24-hydroxy-(24-/sup 3/H) vitamin D/sub 3/ isomers. The 24R-hydroxy-(24-/sup 3/H)vitamin D/sub 3/ induced calcification in rachitic rats while the 24S-hydroxy-(24-/sup 3/H)vitamin D/sub 3/ had little or no such activity. As both isomers of 24-hydroxy-vitamin D/sub 3/ are metabolized to 24,25-dihydroxyvitamin D/sub 3/, it appears that the 24-hydroxyvitamin D/sub 3/-25-hydroxylase does not discriminate between the isomers. Only the R-isomer of 24-hydroxyvitamin D/sub 3/ is metabolized to 1,24-dihydroxyvitamin D/sub 3/, although only trace amounts of this compound were found 2 days after the administration of 24-hydroxyvitamin D/sub 3/. The striking difference in the metabolism of the isomers is the high selectivity of the 1-hydroxylase for the R-isomer. It is suggested that the high specificity of biological activity for the R-isomer of 24-hydroxyvitamin D/sub 3/ is because of the specificity of the 1-hydroxylation of 24,25-dihydroxyvitamin D/sub 3/ for the R configuration.

• OSTI ID: 6790160
• Journal Information: Arch. Biochem. Biophys.; (United States), Journal Name: Arch. Biochem. Biophys.; (United States) Vol. 177; ISSN ABBIA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CHOLECALCIFEROL
CHROMATOGRAPHY
DISEASES
ENZYMES
HYDROGEN ISOTOPES
HYDROXYLASE
HYDROXYLATION
ISOMERS
ISOTOPES
KIDNEYS
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
METABOLISM
NUCLEI
ODD-EVEN NUCLEI
ORGANS
OXIDOREDUCTASES
RADIOISOTOPES
RATS
RICKETS
RODENTS
SEPARATION PROCESSES
SKELETAL DISEASES
STEREOCHEMISTRY
SYNTHESIS
TRITIUM
VERTEBRATES
VITAMIN D
VITAMINS
YEARS LIVING RADIOISOTOPES