- CHENODEOXYCHOLIC ACID SYNTHESIS IN THE HAMSTER: A METABOLIC PATHWAY VIA 3β,7α-DIHYDROXY-5-CHOLEN-24-OIC ACID
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The quantitative significance of the metabolism of 3β,7α-dihydroxy-5-cholen-24-oic acid to chenodeoxycholic acid was evaluated in the hamster.A precursor-product relationship was established in this species by the finding that intravenous administration to an animal previously given cholesterol-4-14C caused a significant reduction in the specific activity of chenodeoxycholic acid.Administration of 12.9 μmole of the precursor was followed by a 10-fold increase in chenodeoxycholic acid excretion although the predominant excretory pathway was via biliary excretion as a monosulfate.The data indicate that synthesis of bile acid from cholesterol via the intermediate 3β,7α-dihydroxy-5-cholen-24-oic acid can be a quantitatively important pathway.
- Kulkarni, Bharti,Javitt, Norman B.
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- Synthesis of potential C27-intermediates in bile acid biosynthesis and their deuterium-labeled analogs
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In connection with studies of alternative pathways in bile acid biosynthesis, potential intermediates in a pathway starting with 27-hydroxylation of cholesterol have been prepared in natural and deuterated forms. Established methods were used to prepare 27-hydroxycholesterol and 3β-hydroxy-5-cholestenoic acid. Clemmensen reduction of kryptogenin in unlabeled and deuterated solvents yielded 27-hydroxycholesterol and 16-oxo-5-cholestene-3β,27-diol, which were separated by adsorption chromatography on Unisil. The labeled 27-hydroxycholesterol and 3β-hydroxy-5-cholestenoic acid derived from it consisted of molecules with seven (50%), six (20%), and eight (20%) deuterium atoms, and unlabeled molecules were not detected. The acetates of 27-hydroxycholesterol and methyl 3β-hydroxy-5-cholestenoate were 7α-hydroxylated in a copper-catalyzed reaction with ert-butylperbenzoate, and the products were purified by chromatography on Unisil. The 7β-epimers were obtained as side products. Labeled 3β, 7α-dihydroxy-5-cholenic acid was prepared in the same way from 3β-hydroxy-5-[2,2,4,4,23-2H5]-cholenoic acid. The 3-oxo-Δ4 analogs of the 3β-hydroxy-Δ5 compounds were prepared by oxidation with cholesterol oxidase. The labeled products had the same isotopic composition as the starting materials. Gas chromatographic retention indices and mass spectral characteristics of the trimethylsilyl ether derivatives of the neutral steroids and the methylated acids are given for all compounds. (Steroids 58:119-125, 1993).
- Shoda, Junichi,Axelson, Magnus,Sjoevall, Jan
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p. 119 - 125
(2007/10/02)
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- A convenient synthesis of 3β,12α-, 3β,7α-, and 3β,7β-dihydroxy-5-cholen-24-oic acids: Unusual bile acids in human biological fluids
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The unusual bile acids 3β,12α- (V), 3β,7α- (XIIIa), and 3β,7β- (XIIIb) dihydroxy-5-cholen-24-oic acids were synthesized conveniently from the 3-oxo derivatives of deoxycholic (I) and lithocholic (VI) acids, respectively, to provide authentic samples for the gas chromatography-mass spectrometric determination of these bile acids in the abnormal metabolism of bile acids.
- Tohma,Mahara,Takeshita,Kurosawa
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p. 331 - 338
(2007/10/02)
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