Vitamin E is a collective name for all stereoisomers of tocopherols and tocotrienols.The most biologically active form is α-tocopherol, butβ-, γ-, δ-tocopherols,4 tocotrienols, and several stereoisomers may also have important biologicalactivity.  Vitamin E acts as achain-breaking antioxidant and is an efficient free radical scavenger, to protect low-density lipoproteins (LDLs) and polyunsaturated fats in membranesfrom oxidation. A network of other antioxidants (e.g., vitamin C, glutathione)and enzymes maintain vitamin E in its reduced state.