General Information SPPS was performed on a CEM Liberty Blue™ Automated Microwave Peptide Synthesizer and in TELOS Filtration Columns comprise equipped with 20 µm polyethylene frits. Reaction temperatures are stated as heating device temperature of the synthesizer, if not otherwise stated. Deionized water was obtained by an Elga PURELAB 8 Option system (15 MΩ•cm). Reagents obtained from commercial suppliers were used without further purification unless otherwise stated. Protected amino acids and triisopropylsilane (TIS) were purchased from Cambridge Reagents. Rink Amide 4methylbenzhydrylamine (MBHA) resin, DIC, oxyma pure, piperazine and trifluoroacetic acid were purchased from Fluorochem. DMF was purchased from Fisher Scientific. Pteroic acid was purchased from Alfa Aesar. For HPLC mobile phase, HPLC grade CH3CN from Fisher Scientific and trifluoroacetic acid from Fluorochem were used. All were laboratory reagent grade and were used without further purification unless otherwise noted. LC-MS was performed on a 1260 Infinity II from Agilent Technologies. Semi-preparative RP-HPLC was performed on a 1206 Infinity from Agilent Technologies equipped with a Phenomenex Gemini C18, 10.0 x 250 mm, particle size 10 µm, pore size 110 Å or with an ACE C18, 10.0 x 250 mm, particle size 5 µm, pore size 100 Å. Determination of Rink Amide MBHA resin loading was conducted using a ThermoFisher NanoDrop ND-ONE-W spectrophotometer. Absorbance values were measured in 10 mm path-length cuvettes (Fisher Scientific, #11847832).