Pu 2028 plus

All reagents were purchased and used as received. Fmoc-Aib-OH and Fmoc-Acc-OH were purchased from Watanabe Chemical Industries (Hiroshima, Japan). Fmoc-Aadc-OH was prepared from H-Aadc-OH (Ark Pharm, Arlington Heights, IL, USA) via a standard method for Fmoc introduction [43 (link)]. Obtained peptides were purified by preparative HPLC and the purity was estimated by analytical HPLC. Preparative HPLC was performed with a pump system of JASCO PU-2028 Plus (JASCO , Tokyo, Japan) and a Cosmosil 5C₁₈-AR-II column (20 × 250 mm, Nacalai Tesque, Kyoto, Japan) using a linear gradient of 0.1% trifluoroacetic acid (TFA) in CH₃CN and 0.1% aqueous TFA at the flow rate of 5.0 mL min⁻¹, and detection was at 220 nm. Analytical HPLC was carried out with a pump system of JASCO PU-2028 Plus and a Cosmosil 5C₁₈-AR-II column (4.6 × 250 mm, Nacalai Tesque) using a linear gradient of 0.1% TFA in CH₃CN and 0.1% TFA in H₂O (1.0 mL min⁻¹, 220 nm). All peptides were characterized by MALDI-TOF MS using a Bruker Autoflex (Bruker, Billerica, MA, USA) with α-cyano-4-hydroxycinnamic acid (CHCA) as the matrix.