Source: Natural forms of vit E (Free Radical Biology & medicine)
The molecular structure for both tocotrienol and tocopherol consist of a chromanol ring and a 16-carbon phytyl side chain, tocotrienols contain three double bonds in their side chain while tocopherols do not. Thus tocotrienol is known as “the unsaturated form of vitamin E”. Different isoforms of tocotrienols (T3) and tocopherols (T1) are at the position of 5- or 7- of the chromanol ring with either an H or a CH3 group as shown in table 1 above. Additionally, tocotrienols and tocopherols have R configuration at the 2-position and configuration at 2, 4’ and 8’-position respectively as shown in the diagram 1 and 2 above.