Antioxidants and Related Compounds

The most frequently employed stabilizing ingredient in plastics, libers, rubbers, and adhesives is the antioxidant. Since oxidation is a free-radical, chain process, it is to be expected that useful molecules will be those that combine with free radicals to give stable species incapable of further reaction. 

A widely used antioxidant in food products is butylated hydroxytoluene (BHT)  

It is added to a variety of consumer items ranging from chewing gum and potato chips to bread wrapping and vitamin A. When modified as in the fatty derivative, an antioxidant of lower volatility and better compatibility with polyethylene is formed. 

Antioxidants used in rubber compounds often are classified as staining or nonstaining depending on whether or not they develop color in use. In a carbon black-loaded tire tread, a staining material has no drawback. But in the white sidewalls, it is important to use additives that are colorless to start with and stay colorless as they protect against oxidation. Phenylenediamine derivatives are very effective antioxidants but discolor (stain) severely. Where light colors must be preserved, a sulfur-cross-linked, hindered phenol that does not discolor is preferable  

2 -thiobis(4-methyl-6-tcrt-butyl phenol), nonstaining 

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Food and Nutrition Board. 2000. Vitamin E. In Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids A Report of the Panel on Dietary Antioxidants and Related Compound, pp. 193-194. National Academy Press, Washington, D.C. 

Gamache, P.H., McCabe, D.R., Parevez, H., Parvez, S., and Acworth, I.N. 1997. The measurement of markers of oxidative damage, antioxidants and related compounds using HPLC and coulometric array analysis. In Columetric Electrode Array Detectors for HPCL (l.N. Acworth, M. Naoi, S. Parvez, and H. Parvez, eds.) pp. 91-119. VSP Publications, Zeist, The Netherlands. 

AN Masoud, Y N Cha. Simultaneous use of fluorescence, ultraviolet, and electrochemical detectors in high performance liquid chromatography-separation and identification of phenolic antioxidants and related compounds. J High Resolut Chromatogr Comm 5 299-305, 1982. 

The definition proposed by the Panel on Dietary Antioxidants and Related Compounds of the Food and Nutrition Board is that a dietary antioxidant is a substance... 

The antioxidant property of ferulic acid and related compounds from rice bran was reported by Kikuzaki et al, (2002). Their results indicated that these compounds elicit their antioxidant function through radical scavenging activity and their affinity with lipid substrates. Another recent study reported by Butterfield et al, (2002) demonstrated that ferulic acid offers antioxidant protection against hydroxyl and peroxyl radical oxidation in synaptosomal and neuronal cell culture systems in vitro. The effect of ferulic acid on blood pressure (BP) was investigated in spontaneously hypertensive rats (SHR). After oral administration of ferulic acid the systolic blood pressure (SBP) decreased in a dose-dependent manner. There was a significant correlation between plasma ferulic acid and changes in the SBP of the tail artery, suggesting... 

Wiseman H, Quinn P, Halliwell B (1993) Tamoxifen and related compounds decrease membrane fluidity in liposomes mechanism for the antioxidant action of tamoxifen and relevance to its anticancer and cardioprotective actions FEBS Lett 330( 1) 53—56... 

Vitamin E (tocopherol) and related compounds only occur in plants (e.g., wheat germ). They contain what is known as a chro-man ring. In the lipid phase, vitamin E is mainly located in biological membranes, where as an antioxidant it protects unsaturated lipids against ROS (see p. 284) and other radicals. 

Additional information As indicated in the reaction above, the catechol group is very readily oxidised upon exposure to light or air. Oxidation results in such compounds turning brown, solutions of isoprenaline and related compounds must contain antioxidants as preservatives. 

Recently, Maruta et al. [112] have found that methanol extracts of roots of burdock show a significant antioxidant activity in an in vitro lipid peroxidation assay, and have isolated five caffeoylquinic acid derivatives (CQAs) from the roots of burdock (Arctium lappa L ), an edible plant in Japan. Antioxidant activities of DCQAs and related compounds have been investigated by measuring the hydroperoxidation of methyl linolate via radical chain reaction. This study indicates that in this particular system caffeic acid and CQAs are more effective than a-tocopherol. These results approximately agree with our findings [38], Additionally, CQAs as the principle antioxidative substance in burdock root have been characterized. 

Sharma OP. 1976. Antioxidant activity of curcumin and related compounds. Biochem Pharmacol 25 1811-1812. 

Zilliken, F.W. 1981. Isoflavones and related compounds, methods of preparing and using and antioxidant compositions containing the same. US patent 4,264,509. April 28, 1981. 

Shlyapintokh, V.Ya. Ivanov, V.B. Antioxidant action of sterically hindered amines and related compounds. In Developments in Polymer Stabilisation Scott, G., Ed. Applied Science London, 1982 Vol. 5, 41-70. 

In recent times compounds with antioxidant activity have gained much attention. This has occurred in conjunction with the concept that antioxidants play a major scavenging role in many biologic proccesses in health and disease. L-tryptophan and related compounds (mainly related to the indole radical) have been reported to exert antioxidant activity. Whether and to what extent this activity may have biologic significance still need to be established. 

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