Oral Sessions (Day1, Day2, Day3)
Poster Presentations
- Day 3, May 21（Fri.） Room P2 (Zoom)
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3P-63 PDF
Investigation of unknown peaks in LC/MS analysis of abiraterone metabolites in human serum
Abiraterone (Abi) is used for the treatment of castration-resistant prostate cancer. Abi is metabolized to a more active Δ4-abiraterone (D4A) than Abi by 3β-hydroxysteroid dehydrogenase and D4A is further metabolized to keto-5α- and keto-5β-Abi by 5α- and 5β-reductase, respectively. Furthermore, keto-Abi’s are metabolized to their hydroxy metabolites, 3α-OH-5α-Abi and 3β-OH-5α-Abi, and 3α-OH-5β-Abi and 3β-OH-5β-Abi. We found unknown peaks on the extracted ion chromatograms at m/z 348.2322 and m/z 350.2478 when the human serum samples were analyzed after administration of Abi acetate. Based on MS/MS analysis and database analysis using a search engine (MS-FINDER) of the unknown peaks, we predicted that the unknown peak ([M+H]+ m/z 350.2478) could be an isomer of Abi. The unknown peak at m/z 350.2478 was confirmed to be 3α-OH-Abi by its synthesis and analysis.