Prep c18 5 μm

Example 1

Synthesis of SEQ ID NO: 6

The solid phase synthesis as described in Methods was carried out on Novabiochem Rink-Amide resin (4-(2′,4′-Dimethoxyphenyl-Fmoc-aminomethyl)-phenoxyacetamido-norleucylaminomethyl resin), 100-200 mesh, loading of 0.23 mmol/g. The Fmoc-synthesis strategy was applied with HBTU/DIPEA-activation. In position 14 Fmoc-Lys(ivDde)-OH and in position 1 BOC-His(Trt)-OH were used in the solid phase synthesis protocol. The ivDde-group was cleaved from the peptide on resin according to literature (S. R. Chhabra et al., Tetrahedron Lett. 1998, 39, 1603-1606). Hereafter Palm-gGlu-gGlu-OSu was coupled to the liberated amino-group employing DIPEA as base. The peptide was cleaved from the resin with King's cocktail (D. S. King, C. G. Fields, G. B. Fields, Int. J. Peptide Protein Res. 1990, 36, 255-266). The crude product was purified via preparative HPLC on a Waters column (XBridge, BEH130, Prep C18 5 μM) using an acetonitrile/water gradient (both buffers with 0.1% TFA). The purified peptide was analysed by LCMS (Method A).

Deconvolution of the mass signals found under the peak with retention time 11.30 min revealed the peptide mass 4782.6 which is in line with the expected value of 4782.6.

Example 3

Synthesis of SEQ ID NO: 17

The solid phase synthesis was carried out on Rink-resin with a loading of 0.38 mmol/g, 75-150 μm from the company Agilent Technologies. The Fmoc-synthesis strategy was applied with HBTU/DIPEA-activation. In position 1 Boc-Tyr(tBu)-OH and in position 14 Fmoc-Lys(ivDde)-OH was used in the solid phase synthesis protocol. The ivDde-group was cleaved from the peptide on resin according to literature (S. R. Chhabra et al., Tetrahedron Lett. 39, (1998), 1603). Hereafter Fmoc-γ-amino butyric acid was coupled to the liberated amino-group employing the coupling reagents HBTU/DIPEA followed by Fmoc-deprotection with 20% piperidine in DMF. Finally stearic acid was coupled using HBTU/DIPEA. The peptide was cleaved from the resin with King's cocktail (D. S. King, C. G. Fields, G. B. Fields, Int. J. Peptide Protein Res. 36, 1990, 255-266). The crude product was purified via preparative HPLC on a Waters column (XBridge, BEH130, Prep C18 5 μM) using an acetonitrile/water gradient (both buffers with 0.05% TFA). The purified peptide was analysed by LCMS (Method C). Deconvolution of the mass signals found under the peak with retention time 29.59 min revealed the peptide mass 4561.4 which is in line with the expected value of 4561.26.