Thyromimetics: a review of recent reports and patents (2004-2009)

Importance of the field. Thyroid hormones are produced by the thyroid gland and peripheral tissues, and control metabolic rate, including oxygen consumption, lipid metabolism and the cardiovascular system, mainly through binding to and activating thyroid hormone receptors (TRs). Abnormal elevation or lowering of circulating thyroid hormone induces various physiological disorders. As candidates for the treatment of such diseases, various thyromimetics, such as subtype- or tissue-selective TR agonists and antagonists, have been developed. Areas covered in this review. This review focuses on recent reports and patents covering thyromimetics, especially those published in the last 6 years. What the reader will gain: In this review, we classify thyromimetics based on structure. The structures of most thyromimetic compounds are based on those of endogenous thyroid hormones, which consist of a biaryl ether skeleton substituted with iodine, cc-alanine moiety and hydroxyl group at two benzene rings. Many thyromimetics have been developed by replacement of the polar group, changing the bridging oxygen, or introduction of heterocycles. This review provides an overview of the structure-activity relationship. Take home message: Some thyromimetics are subtype- or tissue-selective TR agonists and antagonists, and such compounds have the potential to become novel therapeutic agents, especially in the field of metabolic diseases.