ChemInform Abstract: Direct C-N Coupling of Imidazoles and Benzylic Compounds via Iron-Catalyzed Oxidative Activation of C-H Bonds.

ChemInform ◽  
2011 ◽  
Vol 43 (3) ◽  
pp. no-no
Author(s):  
Qinqin Xia ◽  
Wanzhi Chen ◽  
Huayu Qiu
Keyword(s):  
Xenobiotica ◽  
2003 ◽  
Vol 33 (1) ◽  
pp. 93-106 ◽  
Author(s):  
W. G. Humphreys ◽  
M. T. Obermeier ◽  
S. Chong ◽  
S. D. Kimball ◽  
J. Das ◽  
...  
Keyword(s):  

2011 ◽  
Vol 441 (1) ◽  
pp. 189-198 ◽  
Author(s):  
Christine A. McCary ◽  
Youngdae Yoon ◽  
Candace Panagabko ◽  
Wonhwa Cho ◽  
Jeffrey Atkinson ◽  
...  

Vitamin E isoforms have opposing regulatory effects on leucocyte recruitment during inflammation. Furthermore, in vitro, vitamin E isoforms have opposing effects on leucocyte migration across endothelial cells by regulating VCAM (vascular cell-adhesion molecule)-1 activation of endothelial cell PKCα (protein kinase Cα). However, it is not known whether tocopherols directly regulate cofactor-dependent or oxidative activation of PKCα. We report in the present paper that cofactor-dependent activation of recombinant PKCα was increased by γ-tocopherol and was inhibited by α-tocopherol. Oxidative activation of PKCα was inhibited by α-tocopherol at a 10-fold lower concentration than γ-tocopherol. In binding studies, NBD (7-nitrobenz-2-oxa-1,3-diazole)-tagged α-tocopherol directly bound to full-length PKCα or the PKCα-C1a domain, but not PKCζ. NBD-tagged α-tocopherol binding to PKCα or the PKCα-C1a domain was blocked by diacylglycerol, α-tocopherol, γ-tocopherol and retinol, but not by cholesterol or PS (phosphatidylserine). Tocopherols enhanced PKCα-C2 domain binding to PS-containing lipid vesicles. In contrast, the PKCα-C2 domain did not bind to lipid vesicles containing tocopherol without PS. The PKCα-C1b domain did not bind to vesicles containing tocopherol and PS. In summary, α-tocopherol and γ-tocopherol bind the diacylglycerol-binding site on PKCα-C1a and can enhance PKCα-C2 binding to PS-containing vesicles. Thus the tocopherols can function as agonists or antagonists for differential regulation of PKCα.


2018 ◽  
Vol 115 (44) ◽  
pp. 11232-11237 ◽  
Author(s):  
Yue Zhang ◽  
Wan-Hong Wen ◽  
Jin-Yue Pu ◽  
Man-Cheng Tang ◽  
Liwen Zhang ◽  
...  

Understanding how antibiotic-producing bacteria deal with highly reactive chemicals will ultimately guide therapeutic strategies to combat the increasing clinical resistance crisis. Here, we uncovered a distinctive self-defense strategy featured by a secreted oxidoreductase NapU to perform extracellularly oxidative activation and conditionally overoxidative inactivation of a matured prodrug in naphthyridinomycin (NDM) biosynthesis from Streptomyces lusitanus NRRL 8034. It was suggested that formation of NDM first involves a nonribosomal peptide synthetase assembly line to generate a prodrug. After exclusion and prodrug maturation, we identified a pharmacophore-inactivated intermediate, which required reactivation by NapU via oxidative C-H bond functionalization extracellularly to afford NDM. Beyond that, NapU could further oxidatively inactivate the NDM pharmacophore to avoid self-cytotoxicity if they coexist longer than necessary. This discovery represents an amalgamation of sophisticatedly temporal and spatial shielding mode conferring self-resistance in antibiotic biosynthesis from Gram-positive bacteria.


Circulation ◽  
2000 ◽  
Vol 102 (17) ◽  
pp. 2111-2117 ◽  
Author(s):  
Filomena de Nigris ◽  
Tammam Youssef ◽  
SilviaAnna Ciafré ◽  
Flavia Franconi ◽  
Vittorio Anania ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 30 (6) ◽  
pp. no-no
Author(s):  
A. A. FOKIN ◽  
P. R. SCHREINER ◽  
P. VON RAGUE SCHLEYER ◽  
P. A. GUNCHENKO

ChemInform ◽  
2004 ◽  
Vol 35 (27) ◽  
Author(s):  
Jean Bernadou ◽  
Bernard Meunier
Keyword(s):  

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