[{"from": "human", "value": "Could you provide a description of this molecule? [C][=C][C][=C][Branch2][Ring1][C][C][=Branch1][Ring2][=C][Ring1][=Branch1][C][=Branch1][C][=O][N][C][C][=Branch1][C][=O][O-1][I].[Na+1]"}, {"from": "gpt", "value": "The molecule is an organic sodium salt resulting from the formal reaction of equimolar amounts of 2-iodohippuric acid and sodium. It has been used as a contrast agent in urography. Isotopologues labelled with radioactive iodine were formerly used for determination of effective renal plasma flow. It has also been used labelled with radioactive iodine (iodine-125 or iodine-131) in tests of renal function and in renal imaging. It has a role as a radioopaque medium. It contains a 2-iodohippurate."}]