[{"from": "human", "value": "Could you provide a description of this molecule? [C][C][C][Branch1][=Branch2][C][=C][C][=C][C][=C][Ring1][=Branch1][C][Branch1][=Branch2][C][=C][C][=C][C][=C][Ring1][=Branch1][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][O][C][C][N][Branch1][C][C][C]"}, {"from": "gpt", "value": "The molecule is investigated in clinical trials for treating brain cancer. Chlorotoxin I-131 binds to and reduces the activity of a matrix metalloproteinase (MMP) that regulates functioning of the chloride channels on cell membranes. Chlorotoxin is a small 36-amino-acid peptide that selectively binds to glioma cells but not normal brain parenchyma. It is a synthetic version of a neurotoxin isolated from the venom of the Giant Yellow Israeli scorpion Leiurus quinquestriatus. The synthetic version of this peptide has been manufactured and covalently linked to iodine 131 as a means of targeting radiation to tumor cells in the treatment of brain cancer. The selective effects of Chlorotoxin I-131 are regulated by its action on MMP2 receptors."}]