Biological activities antioxidant

These structurally diverse compounds exhibit a range of biological activities in vitro that may explain their potential health-promoting properties, including antioxidant and anti-inflammatory effects and the induction of apoptosis (Hooper and others 2008). Most of the recent interest in flavonoids as health-promoting compounds is related to their powerful antioxidant properties. The criteria to establish the antioxidant capacity of these compounds is based on several structural characteristics that include (a) the presence of o-dihydroxyl substituents in the B-ring (b) a double bond between positions 2 and 3 and (c) hydroxyl groups in positions 3 and 5. 

A large number of reports on the biological activity of antioxidants in blood plasma and cell membranes verify that vitamin E (VE) is the most significant... 

It should be noted that pharmacological vitamin E is not a free natural RRR-a-tocopherol or synthetic All rac a-tocopherol but its acetate ester. a-Tocopheryl acetate has the phenolic hydroxyl group blocked and therefore, is not a genuine antioxidant, but this compound is very rapidly hydrolyzed in vivo into a-tocopherol. It is interesting that the biological activity of a-tocopheryl acetate is the same as that of a-tocopherol in humans but significantly lower in rats [30]. ( A man is not a rat Professor KU Ingold.)... 

Several different tocopherols are known to have vitamin E activity, but a-tocopherol, a trimethyltocol (Figure 12.9) is the most biologically active. Other less potent forms are the /3-, y- and S-tocopherols, which contain fewer methyl groups. They all have antioxidant properties and a deficiency results in a lack of protection of the unsaturated fatty acids in the membrane phospholipids against oxidation by molecular oxygen. 

In this contribution we want to provide a short overview addressing the current state-of-the-art of water-soluble fullerene derivatives and their potential applications as antioxidant or neuroprotective drug candidates. After summarizing the most prominent concepts of designing water-soluble fullerenes in the first chapter we will present some more recent achievements with respect to biological activities of antioxidant fullerenes, with emphasis on our own results. 

Some biologically important o-quinones can react with the superoxide ion giving catechol derivatives, which may play a role in many diseases. For example, compounds bearing a nitro-catechol moiety have been claimed to be efficient catechol-0-methyl transferase inhibitors (Suzuki et al. 1992, Perez et al. 1992). The transferase is the first enzyme in the metabolism of catecholamine a hyperactivity of this enzyme leads to Parkinson s disease. Therefore, prediction of biological activity and antioxidant properties of quinones is an important challenge for researchers. 

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