[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is a carboxylic ester that is the ethyl ester of fluorescein in its ring-opened acid form and substituted on one of the oxygen functions of the xanthene nucleus by a carboxymethyl group. It has a role as a fluorescent probe. It is an ethyl ester and a dicarboxylic acid monoester. It is functionally related to a fluorescein (acid form)."}, {"from": "gpt", "value": "[C][C][O][C][=Branch1][C][=O][C][=C][C][=C][C][=C][Ring1][=Branch1][C][=C][C][=C][C][=Branch1][C][=O][C][=C][Ring1][#Branch1][O][C][=C][Ring1][O][C][=C][C][=Branch1][Ring2][=C][Ring1][=Branch1][O][C][C][=Branch1][C][=O][O]"}]