[{"from": "human", "value": "Could you provide a description of this molecule? [C][=C][C][=Branch2][Ring2][Ring2][=C][Branch2][Ring1][#C][C][=C][Ring1][=Branch1][O][C][=C][Branch2][Ring1][Ring2][C][=C][Branch1][=Branch1][C][=C][Ring1][=Branch1][I][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O][N][I][I][O]"}, {"from": "gpt", "value": "The molecule is normally synthesized and secreted by the thyroid gland in much smaller quantities than L-tetraiodothyronine (T<sub>4</sub>, levothyroxine, L-thyroxine). Most T3 is derived from peripheral monodeiodination of T4 at the 5 position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3. "}]