Metal-Catalyzed Free Radical Injuries In Childhood: Disorders and Pharmaceutical Intervention

1993 ◽  
pp. 458-478
Author(s):  
Makoto Mino ◽  
Masayuki Miki ◽  
Hiromi Ogihara ◽  
Toru Ogihara ◽  
Hiroshi Yasuda ◽  
...  
Keyword(s):  
Free Radical ◽  
Childhood Disorders ◽  
Pharmaceutical Intervention ◽  
Metal Catalyzed

Free radical-mediated transgene inactivation of macrophages by endotoxin

2000 ◽  
Vol 279 (5) ◽  
pp. L878-L883 ◽  
Author(s):  
Sujatha Dokka ◽  
David Toledo ◽  
Liying Wang ◽  
Xianglin Shi ◽  
Chuanshu Huang ◽  
...  
Keyword(s):  
Free Radical ◽  
Plasmid Dna ◽  
Transfection Efficiency ◽  
Gene Transfection ◽  
Cationic Liposome ◽  
Sodium Formate ◽  
Cell Types ◽  
Polymyxin B ◽  
Free Radical Scavengers ◽  
Metal Catalyzed

Endotoxin, the lipopolysaccharide component of gram-negative bacteria, is a common contaminant of plasmid DNA preparations. The present study investigated the effect of endotoxin on gene transfection efficiency and the role of reactive oxygen species (ROS) in this process. Gene transfection studies were performed in various cell types with cytomegalovirus-luciferase as a reporter plasmid and cationic liposome as a transfecting agent. The presence of endotoxin in plasmid DNA preparations severely limited transgene expression in macrophages but had little or no effect in other cell types tested. This decreased transfection was dependent on ROS-mediated cellular toxicity induced by endotoxin. Neutralizing the endotoxin by the addition of polymyxin B effectively increased transfection efficiency and reduced toxicity. Electron spin resonance studies confirmed the formation of ROS in endotoxin-treated cells and their inhibition by free radical scavengers. The ROS scavenger N- t-butyl-α-phenylnitrone, the H2O2 scavenger catalase, and the ·OH scavenger sodium formate effectively inhibited endotoxin-induced effects, whereas the O2 − scavenger superoxide dismutase had lesser effects. These results indicate that multiple oxidative species are involved in the transfection inactivation process and that ·OH formed by H2O2-dependent, metal-catalyzed Fenton reaction play a major role in this process.

Synthesis of 1-Trifluorometylindanes and Close Structures: A Mini Review

Organics ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 348-364
Author(s):  
Olesya V. Khoroshilova ◽  
Aleksander V. Vasilyev
Keyword(s):  
Free Radical ◽  
Transition Metal ◽  
Biologically Active ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Stereo Selectivity

This review describes methods for the synthesis of 1-trifluomethylindanes and close structures, which are still quite rare and scarcely available compounds. There are two main approaches to obtain 1-CF3-indanes. The first one is the construction of an indane system from CF3 precursors; the main methods are acid-mediated Friedel–Crafts cyclization, transition metal-catalyzed [3+2] annulation, and free-radical transformations. The second approach is the trifluoromethylation of a ready-made indane core by various CF3 sources, such as Ruppert–Prakash or Togni reagents. Many of these synthetic procedures possess high regio- and stereo-selectivity, allowing the preparation of unique 1-CF3-indane structures. In recent years, great attention has been paid to the synthesis of 1-CF3-indanes, due to the discovery of important biologically active properties for these compounds.

Potentiation of bromotrichloromethane hepatotoxicity in male rats exposed to 10 ppm dietary chlordecone: Electron Microscopic and biochemical study

1990 ◽  
Vol 48 (3) ◽  
pp. 284-285
Author(s):  
O. M. Faroon ◽  
R. W. Henry ◽  
M. G. Soni ◽  
H. M. Mehendale
Keyword(s):  
Free Radical ◽  
Biochemical Study ◽  
Prior Exposure ◽  
Male Rats ◽  
Cellular Injury ◽  
Low Doses ◽  
Mixed Function Oxidase ◽  
Electron Microscopic ◽  
Potent Inducer ◽  
Cellular Energy

Previous work has shown that mirex undergoes photolytic dechlorination to chlordecone (CD) (KeponeR) in the environment. Much work has shown that prior exposure to nontoxic levels of CD causes potentiation of hepatotoxicity and lethality of CCl4, BrCCl3 and other halomethane compounds. Potentiation of bromotrichloromethane hepatotoxicity has been associated with compounds that stimulate the activity of hepatic mixed-function oxidase (MFO). An increase in the metabolism of halomethane by the MFO to a free radical initiates peroxidative decomposition of membranal lipids ending in massive cellular injury. However, not all MFO inducers potentiate BrCCl3 hepatotoxicity. Potentiation by much larger doses of phenobarbital is minimal and th at by a more potent inducer of MFO, mirex, is negligible at low doses. We suggest that the CD and bromotrichloromethane interaction results in a depletion of cellular energy and thereby reducing the cellular ability to undergo mitosis.

Chelation-assisted transition metal-catalysed C–H chalcogenylations

2020 ◽  
Vol 7 (8) ◽  
pp. 1022-1060 ◽  
Author(s):  
Wenbo Ma ◽  
Nikolaos Kaplaneris ◽  
Xinyue Fang ◽  
Linghui Gu ◽  
Ruhuai Mei ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Advances ◽  
Site Selectivity ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

This review summarizes recent advances in C–S and C–Se formations via transition metal-catalyzed C–H functionalization utilizing directing groups to control the site-selectivity.

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