Vitamin E (tocopherol and related compounds)
This molecule is
alpha tocopherol - with
3 methyl groups.
Beta tocopherol has 2 (5 & 8),
tau tocopherol has 2 (7 & 8),
delta tocopherol has 1 (8).
Show numbers on ring.
The
hydroxyl group gives antioxidant properties, by capturing free radicals, and becomes
converted into a
quinone.
Vitamin E quinone also acts as an anticoagulant, preventing blood clotting.
There are several similar compounds.
The tocotrienols share the same ring structure, but have an unsaturated tail (with 3 double bonds). Both tocopherols and tocotrienols can have from 1 to 3 methyl groups on the aromatic ring.
The side chain is an isoprenoid chain. Interestingly, it can be traced back to a phytyl group attached to chlorophyll which is removed when plant material is digested by herbivores.