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

1. Oleic acid and glucose regulate glucagon-like peptide 1 receptor expression in a rat pancreatic ductal cell line

2. Cationic cell-penetrating peptides are potent furin inhibitors

3. Extended exenatide administration enhances lipid metabolism and exacerbates pancreatic injury in mice on a high fat, high carbohydrate diet

4. cRGD-functionalized, DOX-conjugated, and 64Cu-labeled superparamagnetic iron oxide nanoparticles for targeted anticancer drug delivery and PET/MR imaging

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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.