Synthesis and biological evaluation of 2-(3,4-dimethoxyphenyl)-6-(2-[18F]fluoroethoxy)benzothiazole ([18F]FEDBT) for PET imaging of breast cancer

Bioorg Med Chem Lett. 2017 Aug 1;27(15):3460-3463. doi: 10.1016/j.bmcl.2017.05.079. Epub 2017 May 26.

Abstract

Given the ever-present demand for improved PET radiotracer in oncology imaging, we have synthesized 2-(3,4-dimethoxyphenyl)-6-(2-[18F]fluoroethoxy)benzothiazole ([18F]FEDBT), a fluorine-18-containing fluoroethylated benzothiazole to explore its utility as a PET imaging tracer. [18F]FEDBT was prepared via kryptofix-mediated nucleophilic substitution of the tosyl group precursor. Fractionated ethanol-based solid-phase (SPE cartridge-based) purification afforded [18F]FEDBT in 60% radiochemical yield (EOB), with radiochemical purity in excess of 98% and the specific activity was 35GBq/μmol. The radiotracer displayed clearly higher cellular uptake ratio in various breast cancer cell lines MCF7, MDA-MB-468 and MDA-MB-231. However, both biodistribution and microPET studies have showed an higher abdominal accumulation of [18F]FEDMBT and the tumor/muscle ratio of 1.8 was observed in the MDA-MB-231 xenograft tumors mice model. Further the lipophilic improvement is needed for the reducement of hepatobilliary accumulation and to promote the tumor uptake for PET imaging of breast cancer.

Keywords: Benzothiazole; Breast cancer; Fluorine-18; Positron emission tomography.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzothiazoles / chemistry*
  • Benzothiazoles / pharmacokinetics
  • Breast / diagnostic imaging*
  • Breast Neoplasms / diagnostic imaging*
  • Cell Line, Tumor
  • Female
  • Fluorine Radioisotopes / chemistry*
  • Fluorine Radioisotopes / pharmacokinetics
  • Humans
  • Mice, Inbred NOD
  • Mice, SCID
  • Positron-Emission Tomography / methods*
  • Tissue Distribution

Substances

  • Benzothiazoles
  • Fluorine Radioisotopes