Synthesis of 5-[¹⁸F]Fluoro-α-methyl Tryptophan: New Trp Based PET Agents.

ABSTRACT: Indoleamine 2,3-dioxygenase (IDO1) plays a special role in the biology of various cancer types, because it breaks down the essential amino acid tryptophan for immune cell activation. Upregulation of IDO1 significantly correlates with the number of various T cell types in tumor tissues in melanoma and other cancers, suggesting that IDO expression is linked with effective and ineffective ('exhausted') immune response in cancer. Based on the reported IDO inhibitors (α-Methylated and indole-N-methylated tryptophan (Trp)), here we report the synthesis of potential IDO1 imaging agents through direct introduction of ¹⁸F into the tryptophan aromatic ring. Overall, the resulting PET agents could be obtained in high radiochemical purity (>97%) with labeling yield ranges from 4.2-14

SUBMITTER: Giglio BC 

PROVIDER: S-EPMC5436511 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature