User:Gouriprasanna

Selenium Analogues of Antithyroid Drugs: The overproduction of T4 and T3 can be controlled by blocking the thyroid hormone biosynthesis or reducing the conversion of T4 to T3. The thiourea drugs such as methimazole (MMI), carbimazole (CBZ), 6-propyl-2-thiouracil (PTU), and 6-methyl-2-thiouracil (MTU) are generally employed for this purpose. While MMI and PTU are preferred antithyroid drugs in the United States, MMI is used for most of the hyperthyroid patients in Europe and Asia. In the United Kingdom, the N,N-disubstituted compound carbimazole (CBZ), which is considered to be a prodrug for MMI, is used for such purpose. In recent years, the selenium analogues of MMI (MSeI), CBZ (Se-CBZ), PTU (PSeU) and MTU (MSeU) attracted considerable attention. The initial assumption for the selection of the Se analogues was that the Se compounds may exhibit much higher inhibitory activity towards ID-1 as compared with their S analogues due to their high nucleophilic character. As these compounds are expected to react with the selenenyl iodide intermediate of ID-1, the formation of an Se-Se bond may occur more readily than the formation of an Se-S bond. In addition to their inhibitory action, the Se analogues may have significant effect on H2O2 which is an important substrate for the biosynthesis of thyroid hormones. There are numerous examples of Se compounds that mimic the action of GPx by catalytically reducing H2O2 and organic peroxides with the help of thiol cosubstrates.