21012-75-9 His-ser-asp-gly-thr-phe-ome Histidyl-seryl-aspartyl-glycyl-threonyl-phenylalanine-O-methyl- L-Phenylalanine, N-(N-(N-(N-(N-L-histidyl-L-seryl)-L-alpha-aspartyl)glycyl)-L-threonyl)- Secretin (1-6) Secretin, N-terminal hexapeptide