Positron Emission Tomography Tracer Design of Targeted Synthetic Peptides via F-Sydnone Alkyne Cycloaddition.

Chemically synthesized, small peptides that bind with high affinity and specificity to CD8-expressing (CD8+) tumor-infiltrating T cells, yet retain the desirable characteristics of small molecules, hold valuable potential for diagnostic molecular imaging of immune response. Here, we report the development of F-labeled peptides targeting human CD8α with nanomolar affinity via the strain-promoted sydnone-alkyne cycloaddition with 4-[F]fluorophenyl sydnone. The F-sydnone is produced in one step, in high radiochemical yield, and the peptide labeling proceeds rapidly.

Epitope-Targeted Macrocyclic Peptide Ligand with Picomolar Cooperative Binding to Interleukin-17F.

The IL-17 cytokine family is associated with multiple immune and autoimmune diseases and comprises important diagnostic and therapeutic targets. This work reports the development of epitope-targeted ligands designed for differential detection of human IL-17F and its closest homologue IL-17A. Non-overlapping and unique epitopes on IL-17F and IL-17A were identified by comparative sequence analysis of the two proteins.

Nickel-catalyzed Csp2-Csp3 bond formation by carbon-fluorine activation.

We report herein a general catalytic method for Csp(2)-Csp(3) bond formation through C-F activation. The process uses an inexpensive nickel complex with either diorganozinc or alkylzinc halide reagents, including those with β-hydrogen atoms. A variety of fluorine substitution patterns and functional groups can be readily incorporated.