Rapid preparation of tritium-labeled bile acids by enolic exchange on basic alumina containing tritiated water
When a 3-keto bile acid methyl ester was chromatographed on basic alumina inactivated with tritiated water, the enolic hydrogen atoms at C-2 and C-4 exchanged with tritium atoms. The 3H-labeled keto ester was reduced with borohydride, and the resultant mixture of 3α- and 3β-hydroxy epimers was resol...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
1968-11-01
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| Series: | Journal of Lipid Research |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520426823 |
| Summary: | When a 3-keto bile acid methyl ester was chromatographed on basic alumina inactivated with tritiated water, the enolic hydrogen atoms at C-2 and C-4 exchanged with tritium atoms. The 3H-labeled keto ester was reduced with borohydride, and the resultant mixture of 3α- and 3β-hydroxy epimers was resolved by preparative thin-layer chromatography to yield a pure 2,4-3H-labeled bile acid ester. Lithocholic, chenodeoxycholic, deoxycholic, and cholic acids having a specific activity of 1-10 μc/μmole were prepared from their 3-keto derivatives. The tritium label remained intact during alkaline saponification in vitro and enterohepatic cycling in vivo in human subjects |
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| ISSN: | 0022-2275 |