ABSTRACT
In 1922, Evans and Bishop discovered a new nutritional factor, initially termed “factor X,” later vitamin E and tocopherol, that was essential for a normal devel-opment of fetuses in pregnant rats. They found wheat germ oil to be a particularly rich source of this fat-soluble vitamin. Several compounds with vitamin E activity were subsequently isolated and named α-, β-, and γ-tocopherol. The structure of α-tocopherol was elucidated in 1937 and the next year its first synthesis was achieved. A variety of signs of vitamin E deficiency have been reported in birds and small mammals but rarely in humans. The exact biochemical function of vitamin E in the latter is subject to ongoing debate. In the early years of vitamin E research several bioassays were developed, e.g., the fetus resorption test in rats.
