monoiodotyrosine

noun

mono·​iodo·​ty·​ro·​sine -ī-ˌōd-ə-ˈtī-rə-ˌsēn, -ī-ˌäd-ə- 

: an iodinated tyrosine C₉H₁₀INO₃ that is produced in the thyroid gland by the substitution of one iodine atom in the amino acid for an atom of hydrogen, that undergoes further iodination to produce diiodotyrosine, and that combines with diiodotyrosine to form triiodothyronine