[{"from": "human", "value": "Use the given information to create a molecule that fulfills the desired purpose. The molecule is a (13)C-modified compound that is apspartic acid in which the carbon atoms at postions 1 and 4 are present as their (13)C isotopes. It is a (13)C-modified compound and an aspartic acid."}, {"from": "gpt", "value": "[C][Branch1][#Branch2][C][Branch1][=Branch1][13C][=Branch1][C][=O][O][N][13C][=Branch1][C][=O][O]"}]