Ranalexin is an antibacterial peptide extracted from the skin of a bullfrog. It can resist the invasion of foreign microorganisms and at the same time remove the cells of the ice wall in the body. It is a very important defense system in the organism. Ranalexin is a peptide composed of 20 amino acids with a stable disulfide bond ring space structure. Ranalexin not only has an antibacterial effect, but also destroys parasites, has a broad-spectrum antibacterial effect, especially has strong antibacterial activity against Gram-negative bacteria and fungi.