300 or 400 mhz spectrometer

All NMR spectra were recorded on a Bruker 300 or 400 MHz spectrometer. The chemical shifts were reported in ppm, and J values were reported in Hz. Peptides were purified on a Grace VYDACÒ 218TP152025 C18 column connected to a preparative-HPLC system with Waters 2535 Quaternary Gradient Module, Waters 515 HPLC pump, Waters SFO system Fluidics Organizer and Waters 2767 Sample Manager. Analytical HPLC trace after purification was obtained using a Grace VYDACÒ 218TP C18 5m column connected to an HPLC system with Agilent 1260 Infinity Quaternary Pump VL, Agilent 1260 Infinity Manual Injector and Agilent 1260 Infinity Variable Wavelength Detector. The outlet of the above HPLC system was connected to Thermo Finnigan LCQ Deca XP to obtain MS spectrums of purified peptides.
Starting materials for organic synthesis were purchased from common commercial suppliers including Sigma-Aldrich, TCI and Alfa and used without further purification. All reactions were monitored by TLC Silica gel 60 F254 from Merck. Flash column chromatography was performed with silica gel purchased from Grace (40-63 micron). All Fmoc-protected amino acids for and coupling reagents for solid phase peptide synthesis were purchased from GL Biochem (Shanghai, China).