Radical Antioxidants

Halliwell, B., Free radicals, antioxidants, and human disease curiosity, cause, or consequence Lancet, 344, 721,1994. 

Cellular and extracellular mechanisms that exist to limit the toxicity of free radicals (antioxidants) are known to be deficient in diabetes... 

The additional protection given to nylon by antioxidants has already been mentioned. Since the need is to protect against oxidation by free radicals, antioxidants are essentially of two types peroxide decomposers and radical scavengers. Reviews of these products are available [409,410,413] these should be consulted for details of the mechanisms involved. Peroxide decomposer types include compounds of manganese (II) or copper(I) and copper(II) complexes, such as azomethine bridge derivatives of the type represented by 10.160, of which numerous water-soluble or water-insoluble variants are possible [409]. These products have a catalytic action and are therefore used in very small amounts. 

Orange (Citrus sinensis) was found to be more active than pink grapefruit (Citrus paradisi) in scavenging peroxyl radicals, whereas grapefruit juice was more active than orange juice, when the oxygen radical antioxidant capacity (ORAC) assay was used... 

Reactions Limited by Rotational Diffusion in Polymer Matrix Antioxidants Reacting with Peroxyl Radicals Antioxidants Reacting with Alkyl Radicals Cyclic Chain Termination in Oxidized Polymers... 

ORAC Oxygen radical antioxidant capacity. Rice-Evans447... 

K15. Knight, J. A., Free Radicals, Antioxidants, Aging and Disease. American Association for Clinical Chemistry, Washington, DC, 1999. 

Fang, Y.Z., Yang, S., Guoyao, W. (2002). Free radicals, antioxidant, and nutricion. Nutrition 18 872-9. 

Fang Y-Z, Yang S, Wu G. (2002) Free radicals, antioxidants and nutrition. Nutrition 18 872-879. 

In many cases, the described health effect is antioxidative. Antioxidative properties of a food ingredient can influence different health-related effects in the body. The energy metabolism in our body cells is based on oxidation, which can also lead to the formation of unwanted substances, e.g. free radicals. Antioxidants protect the cells from such damage. The health effect of antioxidative substances varies, among others, from cardiovascular protection to cancer prevention and strengthening of the immune system. 

TRAP (total radical antioxidant parameter) assay 857... 

Keywords Free radicals, antioxidants, selenium, tellurium, hemolytic substitution, chiral stannanes, enantioselective... 

Halliwell, B., Gutteridge, J.M., and Gross, C.E. Free radical antioxidants and human disease. Where are we now Journal of Laboratory and Clinical Medicine, 119, 598-620. 1992. 

Various carbonyl compounds and decomposition products of methyl linolenate hydroperoxides were tested for their interaction with DNA by measuring fluorescence in the presence of ferric chloride and ascorbic acid. 2,4-Alkadienals and 2,4,7-decatrienals were among the most active decomposition products of linolenate hydroperoxides (Table 5.8). To determine the type of reactive species involved in fluorescence formation with DNA, the effect of free radical antioxidants and a singlet oxygen quencher were examined. )3-Carotene, a-tocopherol and phenolic antioxidants strongly inhibited DNA fluorescence formed by decomposition of linolenate hydroperoxides in the presence of ferric chloride and ascorbic acid (Table 5.9). These results indicate that singlet oxygen and free radical species are important intermediates in the interaction of linolenate hydroperoxides with DNA in the presence of iron and ascorbic acid. 

Sun, Y., 1990, Free radicals, antioxidant enzymes, and carcinogenesis. Free Rad. Biol. Med. 8 583-599. 

Halhwell, B., Free Radicals, Antioxidants, and Human Disease Curiosity, Cause, or Consequence Lancet 1994 344 721-724. 

---