Title:Selected Heterocyclic Compounds as Antioxidants. Synthesis and Biological Evaluation
Volume: 14
Issue: 22
Author(s): E. Tsolaki, P. Nobelos, A. Geronikaki and E.A. Rekka
Affiliation:
Keywords:
Antioxidant activity, Antioxidants, Evaluation, Heterocyclic compounds, Oxidative stress, Synthesis.
Abstract: Reactive oxygen species, oxidative stress, and oxidative damage are increasingly assigned important
roles as harmful factors in pathological conditions and ageing. ROS are potentially reactive molecules
derived from the reduction of molecular oxygen in the course of aerobic metabolism. ROS can also
be produced through a variety of enzymes. Under normal circumstances, ROS concentrations are tightly
controlled by physiological antioxidants. When excessively produced, or when antioxidants are depleted,
ROS can impose oxidative damage to lipids, proteins, sugars and DNA. This reduction-oxidation imbalance,
called oxidative stress, can subsequently contribute to the development and progression of tissue
damage and play a role in the pathology of various diseases. An antioxidant is defined as “any substance that, when present
at low concentrations compared with those of a substrate, significantly delays, prevents or removes oxidative damage
to this target molecule”. Despite evidence that oxidative damage contributes to a wide range of clinically important conditions,
few antioxidants act as effective drugs in vivo. Inter alia, the difficulty of measuring antioxidant efficacy in vivo
makes the interpretation of results from clinical trials difficult. A large number of synthetic compounds have been reported
to possess antioxidant activity. Several of them derive from natural antioxidants, others have various structures. In
this review, some of the most often reported classes of heterocyclic antioxidant compounds, as well as methods for
evaluation of their antioxidant activity are discussed.
