N-acetyl-L-thyroxine

N-acetyl-L-thyroxine is a tetraiodinated tyrosine derivative featuring a 3,5-dihydroxyphenyl ring linked to a 4-iodophenyl group via an acetylated aminoethyl bridge. The acetylation at the primary amine of the thyroxine side chain introduces an N-acetyl functional group, while retaining four iodine atoms and two phenolic hydroxyls. This compound represents a chemically modified analog of L-thyroxine, with the acetylation blocking amine reactivity. It serves as an HPLC reference standard for thyroxine derivative analysis.