Synthesis of tritium-labeled puerarin-a potential antidipsotropic agent

• Published in: Journal of labelled compounds & radiopharmaceuticals 2007-07, Vol.50 (8), p.702-705
• Main Authors: Lee, D. Y. W., Ji, X. S., Zhang, X.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Contrast media. Radiopharmaceuticals; isoflavone C-glycosides; Medical sciences; Pharmacology. Drug treatments; synthesis; tritium-labeled puerarin
• ISSN: 0362-4803; 1099-1344
• DOI: 10.1002/jlcr.1398

Puerarin 1 (8‐β‐D‐Glucopyranosyl‐4′‐7‐dihydroxyisoflavone, NPI‐031G) is the major isoflavone C‐glycoside isolated from Pueraria lobata, a traditional Chinese medicine widely used for the treatment of alcohol intoxication. In order to understand the mode of action of puerarin in the reward pathway of the central nervous system and to study its bioavailability and pharmacokinetics, we developed a synthetic route for the preparation of tritium‐labeled puerarin. The key intermediate 4 was obtained by trimethylsilyl protection of all hydroxyl groups followed by selective deprotection. The corresponding aldehyde 5 was obtained through the subsequent oxidation of the primary alcohol. Standard NaB[3H]4 reduction and hydrolysis produced the tritium‐labeled puerarin 6. Copyright © 2007 John Wiley & Sons, Ltd. Puerarin 1 was treated with 8 equivelents of N‐trimethylsilylacetamide to give the pentatrimethylsilylated compound 2, which was selectively deprotected to afford compound 4. Parikh‐Doering oxidation of 4 gave the corresponding aldehyde 5. Subsequent reduction with NaB[3H]4 provided tritium‐labeled puerarin 6. Copyright © 2007 John Wiley & Sons, Ltd.