Natural Molecules in Neuroprotection and Neurotoxicity

Tocochromanols are a group of amphipathic compounds characterized by a polar chromanol ring attached to a hydrophobic hydrocarbon chain at the C2 position. In terms of side chain saturation, tocochromanols can be divided into tocopherols and tocotrienols, the first having a saturated side chain and the second having three double bonds at position 30, 70, and 11 0 (El-Beltagi and Mohamed, 2013). Fig. 78.1 shows the structure of tocochromanols with two substitution groups at position 5 and 7 of the chromanol ring, which we represent by a methyl group or a hydrogen atom. Regarding the nature of the substitution groups, both tocopherols and tocotrienols exist in four compounds named α, β, γ, and δ (Fig. 78.1) (Springett et al., 2015). The structure of tocochromanols has chiral centers. While tocotrienols and tocophenols share the stereocenter at the C2 position of the chromanol ring, the tocophenols have two more along the phytol chain at positions C40 and C80, so that tocochromanols exist in different stereoisomers (Arai and Kono, 2021).