21163-42-8 CCK-6 Cholecystokinin hexapeptide L-Phenylalaninamide, L-methionylglycyl-L-tryptophyl-L-methionyl-L-alpha-aspartyl- Met-gly-trp-met-asp-phe-NH2 Methionyl-glycyl-tryptophyl-methionyl-aspartyl-phenylalaninamide