- Exploring the Strength of the H-Bond in Synthetic Models for Heme Proteins: The Importance of the N?H Acidity of the Distal Base
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The distal hydrogen bond (H-bond) in dioxygen-binding proteins is crucial for the discrimination of O2with respect to CO or NO. We report the preparation and characterization of a series of ZnIIporphyrins, with one of three meso-phenyl rings bearing both an alkyl-tethered proximal imidazole ligand and a heterocyclic distal H-bond donor connected by a rigid acetylene spacer. Previously, we had validated the corresponding CoIIcomplexes as synthetic model systems for dioxygen-binding heme proteins and demonstrated the structural requirements for proper distal H-bonding to CoII-bound dioxygen. Here, we systematically vary the H-bond donor ability of the distal heterocycles, as predicted based on pKavalues. The H-bond in the dioxygen adducts of the CoIIporphyrins was directly measured by Q-band Davies-ENDOR spectroscopy. It was shown that the strength of the hyperfine coupling between the dioxygen radical and the distal H-atom increases with enhanced acidity of the H-bond donor.
- Alberti, Mariza N.,Polyhach, Yevhen,Tzirakis, Manolis D.,T?dtli, Laura,Jeschke, Gunnar,Diederich, Fran?ois
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supporting information
p. 10194 - 10202
(2016/07/19)
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- Spiro[isobenzofuran-1,4'-piperidin]-3-ones and 3H-spiroisobenzofuran-1,4'-piperidines
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Substituted spiro[isobenzofuran-1,4′-piperidin]-3-ones and 3H-spiroisobenzofuran-1,4′-piperidines capable of modulating NPY5 receptor activity are provided. Such compounds may be used to modulate ligand binding to NPY5 receptors in vivo or in vitro, and are particularly useful in the treatment of a variety of disorders (e.g., eating disorders such as obesity or bulimia, psychiatric disorders, diabetes and cardiovascular disorders such as hypertension) in humans, domesticated companion animals and livestock animals. Pharmaceutical compositions and methods for treating such disorders are provided, as are methods for using such compounds for detecting NPY5 receptors.
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- FKBP inhibitors
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Compounds of formula (I), their salts and solvates, wherein the substituents are as described herein, are FKBP inhibitors.
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