[{"from": "human", "value": "Describe this molecule. [C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][N][C][=Branch1][C][=O][C@H1][Branch1][#Branch2][C][C][C][NH1+1][=C][Branch1][C][N][N][NH3+1]"}, {"from": "gpt", "value": "The molecule is a peptide cation obtained by deprotonation of the carboxy terminus and protonation of the side-chain guanidino group and the amino terminus of Arg-Phe; major species at pH 7.3. It is a conjugate acid of an Arg-Phe."}]