Hexapeptide-9 is a synthetic peptide containing Glutamine, Glycine and Proline residues.

1. High fat diet and GLP-1 drugs induce pancreatic injury in mice

2. SERS spectrum of the peptide thymosin‐β4 obtained with Ag nanorod substrate

3. Constitutive and inflammation-dependent antimicrobial peptides produced by epithelium are differentially processed and inactivated by the commensal Finegoldia magna and the pathogen Streptococcus pyogenes

4. Myotropic activity and immunolocalization of selected neuropeptides of the burying beetle Nicrophorus vespilloides (Coleoptera: Silphidae)

5. C-Peptide replacement therapy and sensory nerve function in type 1 diabetic neuropathy

For example, linear hexapeptide 9 was prepared by removing the –Troc protection on 3 to afford 7 and appending the glycine-pyrrole side chain 5 to give 8. After -Fmoc removal, coupling to 4 afforded the desired branched hexapeptide 9, with only the final cyclization and protection group removal remaining. However, compound 9 proved highly unstable and did not succumb to cyclization.

Curzon, S. S., Garcia, J. M., & Konopelski, J. P. (2015). Total synthesis of nominal cyclocinamide B and investigation into the identity of the cyclocinamides. Tetrahedron letters, 56(23), 2991-2994.