Tocopherols (or TCP) are a class of chemical compounds of which many have vitamin E activity. It is a series of organic compounds consisting of various methylated phenols. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was given the name "tocopherol" from the Greek words â€œt????â€� [birth], and â€œf??e??â€�, [to bear or carry] meaning in sum "to carry a pregnancy," with the ending "-ol" signifying its status as a chemical alcohol. Tocotrienols, which are related compounds, may also have vitamin E activity. All of these various derivatives with vitamin activity may correctly be referred to as "vitamin E." Tocopherols and tocotrienols are fat-soluble antioxidants but also seem to have many other functions in the body. The compound a-tocopherol, a common form of tocopherol added to food products, is denoted by the E number E307. In foods, the most abundant sources of vitamin E are vegetable oils such as palm oil, sunflower, corn, soybean, and olive oil. Nuts, sunflower seeds, seabuckthorn berries, kiwifruit, and wheat germ are also good sources. Other sources of vitamin E are whole grains, fish, peanut butter, goats milk, and green leafy vegetables. Fortified breakfast cereals are also an important source of vitamin E in the United States. Although originally extracted from wheat germ oil, most natural vitamin E supplements are now derived from vegetable oils, usually soybean oil.