[
  {
    "molid": "mol33459",
    "smiles": "O=C([O-])C[N+](CCC(=O)O)CCN(CCC(=O)O)CC(=O)O",
    "microspecies": [],
    "macro_pka_values": [
      {
        "pka_value": 6.3,
        "charge_state_pre": -2,
        "charge_state_post": -3,
        "data_source": "OCHEM"
      }
    ]
  }
]