β-[18F]Fluoro azomycin arabinoside (β-[18F]FAZA): Synthesis, radiofluorination and preliminary PET imaging of murine A431 tumors

Abstract

Background: 1-α-D-(5-Deoxy-5-[18F]fluoroarabinofuranosyl)-2-nitroimidazole([18F] FAZA) is a PET radiotracer that demonstrates excellent potential in imaging regional hypoxia, and is clinically used in diagnosing a wide range of solid tumors in cancer patients. [18F]FAZA, however, is radiofluorinated in only moderate recovered radiochemical yield (rRCY, ~12%). It is postulated that the relative stability of the C1' β-anomeric bond at C5' will make 1-β-D-(5-fluoro-5-deoxyarabinofuranosyl)-2-nitroimidazole (β-FAZA), the β-conformer of FAZA, an attractive candidate for clinical hypoxia imaging. Objectives: The principle goals were to synthesize β-FAZA and β-Ac2TsAZA, the radiofluorination precur..