Antioxidants are classified into two broad divisions, based upon their solubility in a solvent namely water-soluble antioxidants like ascorbic acid, glutathione, lipoic acid and uric acid and lipid soluble antioxidants like carotene and ubiquinol.
In general, water-soluble antioxidants have a function in the cell cytosol and the blood plasma. While lipid-soluble antioxidants and protect the cell membranes from lipid peroxidation.
Vitamin C or ascorbic acid is a type of water-soluble vitamin found in cellular fluids such as cytosol or cytoplasmic matrix. It is the most important antioxidant and can protect biomembranes against lipid peroxidation injury. The enediol moiety in its structure is crucial for its antioxidant activity because this moiety has a 2‐carbon side chain with hydroxyl groups.
Tocopherols, as fat‐soluble antioxidant compounds, represent the main groups of vitamin E together with tocotrienols. Vitamin E, a major lipid soluble antioxidant, functions as the most important membrane-bound antioxidant, neutralizing free radicals, and preventing oxidation of lipids within membranes. Vitamin E is the free radical scavenger in the prevention of chronic diseases.
Classification of antioxidants based on solubility behavior
