- Unified Mechanism of Oxygen Atom Transfer and Hydrogen Atom Transfer Reactions with a Triflic Acid-Bound Nonheme Manganese(IV)-Oxo Complex via Outer-Sphere Electron Transfer
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Outer-sphere electron transfer from styrene, thioanisole, and toluene derivatives to a triflic acid (HOTf)-bound nonheme Mn(IV)-oxo complex, [(N4Py)MnIV(O)]2+-(HOTf)2 (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine), has been shown to be the rate-determining step of different types of redox reactions such as epoxidation, sulfoxidation, and hydroxylation of styrene, thioanisole, and toluene derivatives, respectively, by [(N4Py)MnIV(O)]2+-(HOTf)2. The rate constants of HOTf-promoted epoxidation of all styrene derivatives with [(N4Py)MnIV(O)]2+ and electron transfer from electron donors to [(N4Py)MnV(O)]2+ exhibit a remarkably unified correlation with the driving force of outer-sphere electron transfer in light of the Marcus theory of electron transfer. The same electron-transfer driving force dependence is observed in the oxygen atom transfer from [(N4Py)MnIV(O)]2+-(HOTf)2 to thioanisole derivatives as well as in the hydrogen atom transfer from toluene derivatives to [(N4Py)MnIV(O)]2+-(HOTf)2. Thus, mechanisms of oxygen atom transfer (epoxidation and sulfoxidation) reactions of styrene and thioanisole derivatives and hydrogen atom transfer (hydroxylation) reactions of toluene derivatives by [(N4Py)MnIV(O)]2+-(HOTf)2 have been unified for the first time as the same reaction pathway via outer-sphere electron transfer, followed by the fast bond-forming step, which exhibits the singly unified electron-transfer driving force dependence of the rate constants as outer-sphere electron-transfer reactions. In the case of the epoxidation of cis-stilbene by [(N4Py)MnIV(O)]2+-(HOTf)2, the isomerization of cis-stilbene radical cation to trans-stilbene radical cation occurs after outer-sphere electron transfer from cis-stilbene to [(N4Py)MnIV(O)]2+-(HOTf)2 to yield trans-stilbene oxide selectively, which is also taken as evidence for the occurrence of electron transfer in the acid-catalyzed epoxidation.
- Lee, Yong-Min,Kim, Surin,Ohkubo, Kei,Kim, Kyung-Ha,Nam, Wonwoo,Fukuzumi, Shunichi
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- A facile synthesis of novel miconazole analogues and the evaluation of their antifungal activity
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Four novel miconazole analogues (8-11) were synthetized and evaluated for activity against four filamentous fungi (Mucor hiemalis, Aspergillus fumigatus, Trichosporon cutaneum, and Rhizopus oryzae) and eight species of Candida as yeast specimens. Compounds 9 and 10 showed very good activity when evaluated in yeast (MIC 0.112 and 0.163 μg/mL) compared to the reference compound, itraconazole (MIC 0.067 μg/mL). The best antifungal activity in filamentous strains was shown by compound 9. Hence compounds 9 and 10 represent new leads for further pharmacomodulation in this series.
- Ramírez-Villalva, Alejandra,González-Calderón, Davir,González-Romero, Carlos,Morales-Rodríguez, Macario,Jauregui-Rodríguez, Bertha,Cuevas-Yá?ez, Erick,Fuentes-Benítes, Aydeé
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- SMALL MOLECULE STIMULATORS OF THE CORE PARTICLE OF THE PROTEASOME
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This present disclosure relates to series compounds and methods of use for the treatment of a disease caused by abnormal regulation of the ubiquitin-proteasome system (UPS), and wherein said compound is an effective stimulator of the 20S core particle (CP) of the UPS. Composition matters and methods of uses are within the scope of this disclosure.
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Paragraph 00101
(2021/02/26)
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- Reprogramming Epoxide Hydrolase to Improve Enantioconvergence in Hydrolysis of Styrene Oxide Scaffolds
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Enantioconvergent hydrolysis by epoxide hydrolase is a promising method for the synthesis of important vicinal diols. However, the poor regioselectivity of the naturally occurring enzymes results in low enantioconvergence in the enzymatic hydrolysis of styrene oxides. Herein, modulated residue No. 263 was redesigned based on structural information and a smart variant library was constructed by site-directed modification using an “optimized amino acid alphabet” to improve the regioselectivity of epoxide hydrolase from Vigna radiata (VrEH2). The regioselectivity coefficient (r) of variant M263Q for the R-isomer of meta-substituted styrene oxides was improved 40–63-fold, and variant M263V also exhibited higher regioselectivity towards the R-isomer of para-substituted styrene oxides compared with the wild type, which resulted in improved enantioconvergence in hydrolysis of styrene oxide scaffolds. Structural insight showed the crucial role of residue No. 263 in modulating the substrate binding conformation by altering the binding surroundings. Furthermore, increased differences in the attacking distance between nucleophilic residue Asp101 and the two carbon atoms of the epoxide ring provided evidence for improved regioselectivity. Several high-value vicinal diols were readily synthesized (>88% yield, 90%–98% ee) by enantioconvergent hydrolysis using the reprogrammed variants. These findings provide a successful strategy for enhancing the enantioconvergence of native epoxide hydrolases through key single-site mutation and more powerful enzyme tools for the enantioconvergent hydrolysis of styrene oxide scaffolds into single (R)-enantiomers of chiral vicinal diols. (Figure presented.).
- Li, Fu-Long,Qiu, Yan-Yan,Zheng, Yu-Cong,Chen, Fei-Fei,Kong, Xu–Dong,Xu, Jian-He,Yu, Hui-Lei
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supporting information
p. 4699 - 4706
(2020/09/21)
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- DIARYL MORPHOLINES AS CB1 MODULATORS
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The present invention provides compounds having the general structure of Formula (I) or a pharmaceutically acceptable salt, solvate, ester or prodrug thereof, which are useful as CB1 receptor antagonists. The compounds of the invention may be useful in treating diseases, disorders, or conditions responsive to CB1 receptor antagonists, including, but not limited to, metabolic syndrome, obesity, waist circumference, dyslipidemia, insulin sensitivity, neuroinflammatory disorders, cognitive disorders, psychosis, addictive behavior, gastrointestinal disorders, and cardiovascular conditions.
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Page/Page column 91; 92
(2008/12/08)
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- SUBSTITUTED PIPERAZINES AS CB1 ANTAGONISTS
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Compounds of Formula (I): Chemical formula should be inserted here as it appears on the abstract in paper form. or pharmaceutically acceptable salts, solvates, or esters thereof, are useful in treating diseases or conditions mediated by CB1 receptors, such as metabolic syndrome and obesity, neuroinflammatory disorders, cognitive disorders and psychosis, addiction (e.g., smoking cessation), gastrointestinal disorders, and cardiovascular conditions.
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Page/Page column 190
(2010/11/08)
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- Discovery and initial structure-activity relationships of trisubstituted ureas as thrombin receptor (PAR-1) antagonists
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Thrombin is the most potent agonist of platelet activation, and its effects are predominantly mediated by platelet thrombin receptors. Therefore, antagonists of the thrombin receptor have potential utility for the treatment of thrombotic disorders. Screening of combinatorial libraries revealed 2 to be a potent antagonist of the thrombin receptor. Modifications of this structure produced 11k, which inhibits thrombin receptor stimulated secretion and aggregation of platelets.
- Barrow, James C,Nantermet, Philippe G,Selnick, Harold G,Glass, Kristen L,Ngo, Phung L,Young, Mary Beth,Pellicore, Janetta M,Breslin, Michael J,Hutchinson, John H,Freidinger, Roger M,Condra, Cindra,Karczewski, Jerzy,Bednar, Rodney A,Gaul, Stanley L,Stern, Andrew,Gould, Robert,Connolly, Thomas M
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p. 2691 - 2696
(2007/10/03)
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- Studies on cognitive enhancing agents. II. Antiamnestic and antihypoxic activities of 1-aryl-2-(2-aminoethoxy)ethanols
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A series of 2-(2-aminoethoxy)-1-phenylethanols having a variety of N- and phenyl-substitution patterns as well as 5- and 6-membered heteroaryl counterparts of our prototype compound 1 (2-(2-dimethylaminoethoxy)-1- phenylethanol) have been prepared and evaluated for antiamnestic and antihypoxic activities. Compound 3b, the 3-methylphenyl analogue of 1, proved to be significantly more potent than I in reversing electroconvulsive shock- induced amnesia as well as CO2-induced learning-impairment in mice. It exhibited low acute toxicity in mice and afforded a greater brain/serum concentration ratio than 1 after oral administration to rats.
- Ono,Yamafuji,Chaki,Morita,Todo,Maekawa,Kitamura,Tai,Narita
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p. 1488 - 1491
(2007/10/03)
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