Free Radicals In Chemistry And Biology

Our understanding of the quantitative aspects of free radical chemistry and the involvement of radicals in such areas as biology, medicine, the environment, etc., has developed spectacularly over recent years, yet the various topics are commonly discussed separately, in specific meetings and specialised publications. Free Radicals in Biology and Environment draws together two important areas of free radical chemistry, using as a bridge the fundamental physical chemistry of free radicals (spectroscopic detection of free radicals, evaluation of absolute rate constants, elucidation of mechanisms of free radical reactions and catalysis, photochemical and radiation processes, etc.). The most relevant topics covered are the EPR detection of radicals in biochemical systems and in pollutant formation and degradation, oxidation processes in biology and in the troposphere, radiation and induced damage, and atmospheric pollutants arising from incomplete combustion. Also covered are the chemistry and biochemistry of nitric oxide and peroxynitrite, the chemistry and biochemistry of DNA radicals, the role of radicals in myeloperoxidase, lignineperoxidase, radicals and cardiovascular injury, radiation and the fragmentation of cells and tissues.

Elementary radical reactions are described in terms of fundamental knowledge of organic chemistry and chemical physics in this valuable reference text. The complex radical processes of nonchain and chain mechanisms, such as dimerization, alkylation, polymerization, telomerization, halogenation pyrolysis, oxidation and combustion, are complemented by reactions in chemical lasers and in the cosmos, as well as by reactions in biological objects under normal or pathological metabolism. The text also provides the synthesis of facts from various fields of research and involves mechanisms where free radicals appear either as main or side intermediates in one of the several alternatives of the reaction pathway. Highlights include 38 tables and 39 figures.

"Oxidative stress" is used as the generic term describing the involve ment of reactive oxygen species in various human diseases. The scope of such a topic is becoming increasingly wide. The recent interest in radicals such as nitric oxide and the discovery of new mechanisms such as the effect of free radicals on redox sensitive proteins and genes are enlarging our understanding of the physiological role of free radicals. Oxidative stress is involved in numerous pathological. processes such as ageing, respiratory or cardiovascular diseases, cancer, neurological pathologies such as dementia or Parkinson's disease. It still remains difficult, however, to demonstrate by chemical measurement the in vivo production of free radicals and even more to realise their speciation. Therefore, the development of new tools and indicators is engrossing many researchers working in this field. Reliable indicators are abso lutely necessary not only to monitor the evolution of oxidative stress in patients but also to evaluate the efficiency of new antioxidant treat ments. The French Free radical club of Grenoble, the CERLIB has been involved for many years in the organisation of international training programs on methodology, in order to provide both theoretical and practical help to researchers from various countries. Such training sessions have been highly successful and participants value the oppor tunity to learn reliable techniques. This positive echo explains why the researchers of CERLIB decided, with the help of Prof. Dr. B. Kalyanaraman, to publish selected techniques on free radical re search.

"This latest edition has been comprehensively rewritten and updated (over 80% of the text is new), whilst maintaining the clarity of its predecessor. There is expanded coverage of isoprostanes and related compounds, mechanisms of oxidative damage to DNA and proteins (and the repair of such damage), the free radical theory of ageing and the roles played by reactive species in signal transduction, cell death, human reproduction, and other important biological events. Greater emphasis has also been placed on the methods available to measure reactive species and oxidative damage (and their potential pitfalls), as well as the importance of antioxidants in the human diet." "This book is recommended as a comprehensive introduction to the field for students, clinicians and researchers, and an invaluable companion to all those interested in the role of free radicals in the life and medical sciences."--BOOK JACKET.

Free-radical reactions have been for long time the domain of the physical chemists and the basic chemical industry (polymerization of vinyl monomers, oxidation by molecular oxygen, chlorination of methane etc.), where the use of simple molecules and the possibility of partial conversions without heavy problems of product separations makes less dramatic the aspects of regio and chemoselectivity. As synonym of unselectivity, free radical reactions were considered of poor use in the synthesis of fine chemicals or sophisticated molecules, where a high selectivity is an essential condition for the success, or in the involvement of biological processes. Within the last 15 years, however, an authentic explosion of synthetic applications of free radical reactions occurred; they have gained a remarkable position among the selective methods of synthesis. At the same time the great importance of free radical reactions in fundamental biological processes and in the metabolism of drugs has been recognized. Thus a specialized meeting on these topics was generally felt appropriate. I had the honour and the onus to organize this workshop because for more than 30 years I have been involved in the research of free radical reactions. Thanks to a generous grant from NATO Scientific Affairs Division and the financial support of CNR and chemical industry (Montedison, Enichem, Zambon) such a meeting among almost 50 specialists and 15 observers of sufficient standard to take advantage of the discussion, became possible at Bardolino (Italy).

Free Radicals in Biology and Medicine has become a classic text in the field of free radical and antioxidant research. Now in its fifth edition, the book has been comprehensively rewritten and updated whilst maintaining the clarity of its predecessors. Two new chapters discuss 'in vivo' and 'dietary' antioxidants, the first emphasising the role of peroxiredoxins and integrated defence mechanisms which allow useful roles for ROS, and the second containing new information on the role of fruits, vegetables, and vitamins in health and disease. This new edition also contains expanded coverage of the mechanisms of oxidative damage to lipids, DNA, and proteins (and the repair of such damage), and the roles played by reactive species in signal transduction, cell survival, death, human reproduction, defence mechanisms of animals and plants against pathogens, and other important biological events. The methodologies available to measure reactive species and oxidative damage (and their potential pitfalls) have been fully updated, as have the topics of phagocyte ROS production, NADPH oxidase enzymes, and toxicology. There is a detailed and critical evaluation of the role of free radicals and other reactive species in human diseases, especially cancer, cardiovascular, chronic inflammatory and neurodegenerative diseases. New aspects of ageing are discussed in the context of the free radical theory of ageing. This book is recommended as a comprehensive introduction to the field for students, educators, clinicians, and researchers. It will also be an invaluable companion to all those interested in the role of free radicals in the life and biomedical sciences.

Free Radicals in Biology, Volume 1, provides an introduction to some of the basic concepts of free radical biology. The book emerged from the President's Symposium of the American Society for Experimental Pathology held in Atlantic City in April 1970. The book's opening chapter introduces a mechanistic view of free radical reactions using examples from biological systems. This is followed by a discussion of autoxidative damage to lipids in membranes. Some of the special chemistry of lipid oxidation are presented, and a number of novel ideas are suggested. The third chapter deals with the uses of electron-spin resonance in biology. Spin labeling is also discussed, which is one of the most useful methods of probing the chemical and physical environment of molecules in cells. The remaining chapters cover free radicals which occur in photosynthesis and the importance of the enzyme, superoxide dismutase. The study of the occurrence and reactions of this enzyme provides an important and extensive body of data clearly pointing to the significance of free radicals in cellular chemistry.