Cyclic Peptides

   Cyclo(Arg-Gly-Asp-D-Phe-Lys)                                            5 mg $ 250

                                                                                                  25 mg $ 500

       An RGD tumor-targeting peptide, which binds to αvβ3 receptors. It can be easily conjugated to fluorophore tags, chelators, or carriers. Palecek et al. converted the ε-amino group into the azide by diazo transfer allowing further functionalization by click chemistry. Mercapto groups can be introduced via acylation of this peptide with S-acetylthio- acetic acid (SATA).

Ac-Nle-cyclo(-Asp-His-D-Phe-Arg-Trp-Lys)                           5 mg $ 250
                                                                                               25 mg $ 1016

Melanotan II, a cyclic MSH analog, is a potent full agonist of the melanocortin-3 and melanocortin-4 receptors (MC3-R and MC4-R). Intracerebroventricular administration of MTII inhibited feeding in four different mouse models of hyperphagia. MTII is a valuable tool for the study of the agouti obesity syndrome and of the role of melanocortiner- gic neurons in feeding.