[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is an amino-acid cation obtained by deprotonation of the carboxy group and protonation of the two amino groups of (3R)-3-methyl-D-ornithine; major species at pH 7.3. It is a conjugate acid of a (3R)-3-methyl-D-ornithine."}, {"from": "gpt", "value": "[C][C@H1][Branch1][Ring2][C][C][NH3+1][C@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1]"}]