The studies on the active peptide in the skin of Rana rugosa. II. The structure of ranatensin-R, the new ranatensin analogue, and granuliberin-R, the new mast cell degranulating peptide.

Abstract
The skin of Rana rugosa contained ranatensin-R, a new analogous peptide to ranatensin. Ranatensin-R is heptadecapeptide amide which is a longest analogue of ranatensin ever isolated from the frog skin. Granuliberin-R, dodecapeptide amide, was obtained from the same ranatensin-R fraction during the separation process. The peptide is a new type of amphibian skin peptide which acts on the rat peritoneal mast cell to liberate granules and histamine from the cells.