70-40-6Relevant articles and documents
Biomimetic deiodination of thyroid hormones and iodothyronamines-a structure-activity relationship study
Mondal, Santanu,Mugesh, Govindasamy
supporting information, p. 9490 - 9500 (2016/10/22)
Mammalian selenoenzymes, iodothyronine deiodinases (DIOs), catalyze the tyrosyl and phenolic ring deiodination of thyroid hormones (THs) and play an important role in maintaining the TH concentration throughout the body. These enzymes also accept the decarboxylated thyroid hormone metabolites, iodothyronamines (TAMs), as substrates for deiodination. Naphthalene-based selenium and/or sulphur-containing small molecules have been shown to mediate the regioselective tyrosyl ring deiodination of thyroid hormones and their metabolites. Herein, we report on the structure-activity relationship studies of a series of peri-substituted selenium-containing naphthalene derivatives for the deiodination of thyroid hormones and iodothyronamines. Single crystal X-ray crystallographic and 77Se NMR spectroscopic studies indicated that the intramolecular Se?X (X = N, O and S) interactions play an important role in the deiodinase activity of the synthetic mimics. Furthermore, the decarboxylated metabolites, TAMs, have been observed to undergo slower tyrosyl ring deiodination than THs by naphthyl-based selenium and/or sulphur-containing synthetic deiodinase mimics and this has been explained on the basis of the strength of Se?I halogen bonding formed by THs and TAMs.
NOVEL PROCESS FOR THE PREPARATION OF LEVOTHYROXINE SODIUM
-
Page/Page column 6; 7, (2015/02/19)
The present invention provides a novel process for the preparation of highly pure Levothyroxine Sodium, i.e., (S)-2-amino-3-[4-(4-hydroxy-3, 5-diiodophenoxy)-3,5- diiodophenyl] propanoic acid sodium salt via two process intermediates viz 3,5-Diiodo L- Tyrosine copper complex and novel Bis (p-anisyl) iodonium lodide.The invention also provides levothyroxine pentahydrate free from genotoxic impurities and liothyronine levels below 0.04% wt/wt.
Regioselective deiodination of thyroxine by iodothyronine deiodinase mimics: An unusual mechanistic pathway involving cooperative chalcogen and halogen bonding
Manna, Debasish,Mugesh, Govindasamy
supporting information; experimental part, p. 4269 - 4279 (2012/04/10)
Iodothyronine deiodinases (IDs) are mammalian selenoenzymes that catalyze the conversion of thyroxine (T4) to 3,5,3′-triiodothyronine (T3) and 3,3′,5′-triiodothyronine (rT3) by the outer- and inner-ring deiodination pathways, respectively. These enzymes also catalyze further deiodination of T3 and rT3 to produce a variety of di- and monoiodo derivatives. In this paper, the deiodinase activity of a series of peri-substituted naphthalenes having different amino groups is described. These compounds remove iodine selectively from the inner-ring of T4 and T3 to produce rT3 and 3,3′-diiodothyronine (3,3′-T2), respectively. The naphthyl-based compounds having two selenols in the peri-positions exhibit much higher deiodinase activity than those having two thiols or a thiol-selenol pair. Mechanistic investigations reveal that the formation of a halogen bond between the iodine and chalcogen (S or Se) and the peri-interaction between two chalcogen atoms (chalcogen bond) are important for the deiodination reactions. Although the formation of a halogen bond leads to elongation of the C-I bond, the chalcogen bond facilitates the transfer of more electron density to the C-I σ* orbitals, leading to a complete cleavage of the C-I bond. The higher activity of amino-substituted selenium compounds can be ascribed to the deprotonation of thiol/selenol moiety by the amino group, which not only increases the strength of halogen bond but also facilitates the chalcogen-chalcogen interactions.
