[{"from": "human", "value": "What can you tell me about this molecule? [C][C][N][Branch1][=Branch2][C][C][N][Ring1][=Branch1][C][C][O][C][C][S][=Branch1][C][=O][=Branch1][C][=O][O-1]"}, {"from": "gpt", "value": "The molecule is a HEPES. It is a conjugate base of a 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid and a 2-[4-(2-hydroxyethyl)piperazin-4-ium-1-yl]ethanesulfonate."}]