Interaction of anti-thyroid drugs with iodine: the isolation of two unusual ionic compounds derived from Se-methimazole
作者:Gouriprasanna Roy、Munirathinam Nethaji、G. Mugesh
DOI:10.1039/b604060h
日期:——
The inhibition of lactoperoxidase (LPO)-catalyzed iodination of L-tyrosine by the anti-thyroid drug methimazole (MMI) and its selenium analogue (MSeI) is described. MSeI inhibits LPO with an IC50 value of 12.4 µM, and this inhibition could be completely reversed by increasing the peroxide concentration. In addition to the inhibition, MSeI reacts with molecular iodine to produce novel ionic diselenides, and the nature of the species formed in this reaction appear to be solvent-dependent. The formation of ionic species in the reaction is confirmed by single-crystal X-ray studies, FT-IR and FT-Raman spectroscopic investigations. This study provides the first experimental evidence that MSeI not only effectively inhibits the LPO-catalyzed iodination of tyrosine, but also reacts with I2 to produce novel ionic diselenides. These results also suggest that MSeI reacts with iodine, even in its oxidized form, to form ionic diselenides containing iodide or polyiodide anions, which might be effective intermediates in the inhibition of thyroid hormones.
本文描述了抗甲状腺药物甲巯咪唑(MMI)及其硒类似物(MSeI)对乳过氧化物酶(LPO)催化的 L-酪氨酸碘化的抑制作用。MSeI 可抑制 LPO,其 IC50 值为 12.4 µM,这种抑制作用可通过增加过氧化物浓度而完全逆转。除了抑制作用外,MSeI 还会与碘分子发生反应,生成新的离子二硒化物,这种反应中形成的物种的性质似乎与溶剂有关。单晶 X 射线研究、傅立叶变换红外光谱和傅立叶变换拉曼光谱研究证实了反应中离子物种的形成。这项研究首次提供了实验证据,证明 MSeI 不仅能有效抑制 LPO 催化的酪氨酸碘化反应,还能与 I2 反应生成新型离子二硒化物。这些结果还表明,MSeI 能与碘发生反应,即使是氧化态的碘,也能形成含有碘离子或多碘离子的离子二硒化物,它们可能是抑制甲状腺激素的有效中间体。