Tocopherols (TCP) (vitamin E) are a series (α, β, γ and δ) of chiral organic molecules that vary in their degree of methylation of the phenol moiety of the chromanol ring. Tocopherols are lipid soluble antioxidants that protect cell membranes from oxidative damage. α-Tocopherol is the form of tocopherol preferentially absorbed by homo sapiens. Various isofroms and analogues of tocopherol have opposing and differentiated regulatory activities in vivo.