Fig. 2. A comparison of the chemical characteristics of native (N) and synthetic (S) EI-14. (A) Reverse-phase chromatograms of N, S and N+S using the TSK ODS-120T column. N, S and N+S were eluted with a 50min linear gradient of 20%–30% acetonitrile in 10% 2-propanol and 0.1% trifluoroacetic acid. The flow rate was 0.5mlmin^-1. (B) Cation-exchange chromatograms. Each peptide was eluted with a 25min linear gradient of 0-0.5moll^-1 NaCl in 10% ethanol and 20mmoll^-1 phosphate buffer (pH 6.7). The flow rate was 0.5mlmin^-1.