Editorial [ Combinatorial Antioxidants Guest Editor: Sibel Suzen ]

Free radicals are atoms or groups of atoms with an odd (unpaired) number of electrons and can be formed when oxygen interacts with certain molecules. Once formed these highly reactive radicals can start a chain reaction. Their danger comes from the damage they can do when they react with important cellular components such as DNA, or the cell membrane. Increasingly, their role in a number of human disease processes is being accepted, although conclusive evidence is lacking in many cases, due to the difficulties in detecting free radicals that have very short lifetimes. To prevent free radical damage the body has a defense system of antioxidants. Antioxidants interact with and stabilize free radicals and can prevent some of the damage free radicals otherwise might cause. Antioxidants are intimately involved in the prevention of cellular damage, cancer, aging, and a variety of diseases. However, these benefits have not been confirmed by recent large clinical trials. Research suggests that consumption of antioxidant-rich foods reduces damage to cells and biochemicals from free radicals. This can slow down, prevent, and even reverse certain diseases that result from cellular damage, and perhaps even slow down the natural aging process. An antioxidant may act by catalysis, or, in cells, it may act as a cofactor that transfers reducing equivalents from NADPH. Finding of novel drugs is a very difficult process. Combinatorial chemistry is one of the important methodologies that can help to reduce the time and costs associated with producing new drugs. In the process of finding new drug candidates medicinal chemists nowadays have a variety of options from which to choose, and one is to apply combinatorial chemistry techniques. It is now possible to produce compound libraries to screen for novel bioactivities. In the preparation of drug candidates, the automated, and combinatorial use of chemical building blocks facilitates the generation and screening of large numbers of compounds. Combinatorial chemistry has been proven to be an efficient way of generating libraries of compounds and can be used to identify lead compounds in a short period of time. It is relatively unexplored when considering the discovery of novel anti-oxidative agents. The purpose of this special issue is to serve as a guide to what antioxidants are and to briefly review their role in general health. Recent developments of melatonin related antioxidant compounds, antioxidant containing foods especially in the Black Sea region of Turkey, evaluation and comparison of the ROS generating and LP inducing effect of several halogenated aromatic compounds, the relationship between antioxidants and inflammatory diseases, and finally, combinatorial library synthesis of antioxidant compounds are addressed in this special issue. I would like to thank the authors for their contributions and the editor of Combinatorial Chemistry & High Throughput Screening for the invitation to act as guest editor for this special issue.