[{"from": "human", "value": "Describe this molecule. [C][C][=C][C][=Branch2][Ring2][Branch1][=C][C][=Branch1][Ring2][=C][Ring1][=Branch1][N][C][=Branch1][C][=O][C][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][O][C][Branch1][C][C][Branch1][C][C][C][=Branch1][C][=O][O-1][C].[Na+1]"}, {"from": "gpt", "value": "The molecule is the sodium salt form of efaproxiral, a propanoic acid and allosteric modifier of hemoglobin, with radiosensitizing activity. Efaproxiral binds non-covalently to the hemoglobin tetramer, thereby decreasing hemoglobin-oxygen binding affinity. This results in an increase in oxygen levels in hypoxic tumor tissues; increasing tumor oxygenation reduces tumor radioresistance."}]