53584-04-6Relevant articles and documents
Heme-coordinating inhibitors of neuronal nitric oxide synthase. Iron-thioether coordination is stabilized by hydrophobic contacts without increased inhibitor potency
Martell, Jeffrey D.,Li, Huiying,Doukov, Tzanko,Martasek, Pavel,Roman, Linda J.,Soltis, Michael,Poulos, Thomas L.,Silverman, Richard B.
, p. 798 - 806 (2010)
The heme-thioether ligand interaction often occurs between heme iron and native methionine ligands, but thioether-based heme-coordinating (type II) inhibitors are uncommon due to the difficulty in stabilizing the Fe-S bond. Here, a thioether-based inhibitor (3) of neuronal nitric oxide synthase (nNOS) was designed, and its binding was characterized by spectrophotometry and crystallography. A crystal structure of inhibitor 3 coordinated to heme iron was obtained, representing, to our knowledge, the first crystal structure of a thioether inhibitor complexed to any heme enzyme. A series of related potential inhibitors (4-8) also were evaluated. Compounds 4-8 were all found to be type I (non-heme-coordinating) inhibitors of ferric nNOS, but 4 and 6-8 were found to switch to type II upon heme reduction to the ferrous state, reflecting the higher affinity of thioethers for ferrous heme than for ferric heme. Contrary to what has been widely thought, thioether-heme ligation was found not to increase inhibitor potency, illustrating the intrinsic weakness of the thioether-ferric heme linkage. Subtle changes in the alkyl groups attached to the thioether sulfur caused drastic changes in the binding conformation, indicating that hydrophobic contacts play a crucial role in stabilizing the thioether-heme coordination.
Studies on topical antiinflammatory agents. V. 17-(Alkylthio)- and methoxyalkanoates of corticosteroids
Mitsukuchi,Ikemoto,Taguchi,Higuchi,Abe,Yasui,Hatayama
, p. 692 - 697 (2007/10/02)
As part of our search for new topical antiinflammatory agents, a series of corticosteroid 17-(alkylthio)- and methoxyalkanoate derivatives was prepared and tested for vasoconstrictive activities. Several compounds were proved to have activity superior or comparable to that of 9α-fluoro-11β,21-dihydroxy-16β-methyl-17α-valeryloxy-1,4- pregnadiene-3,20-dione (betamethasone 17-valerate, BV). Among these compounds, 21-chloro-11β-hydroxy-17α-(methylthio)acetoxy-4- pregnene-3,20-dione (5Aa) was found to have the most potent activity, being more active than BV. The structure-activity relationships of the series revealed that introduction of a (methylthio)acetate function into the 17-position as well as the 21-position of corticosteroids was effective for enhancing the topical antiinflammatory activity.
