IUNS-AIN Nomenclature for Vitamin E

Abstract

Abstract An improved new nomenclature system for the biologically and nutritionally important stereoisomers and mixtures of stereoisomers of vitamin K has been proposed. The term vitamin E is used as the generic descriptor for biologically active tocol and tocotrienol derivatives. α-Toeopherol, formerly (d-α-tocopherol, refers specifically to the isomer of trimethyltocol that occurs naturally, All-rac-α-tocopherol, formerly (dl-α-tocopherol, refers to the equimolar mixture of the 8 possible stereoisomers of α-toeopherol obtained by synthesis from racemic isophytol. 2DL-α-Tocopherol, also formerly (dl-α-tocopherol, refers to the equimolar mixture of the 2 C-2 diastereoisomers of a-tocopherol obtained by synthesis from natural phytol. 2L,-α-Tocopherol, formerly l-α-tocopherol, refers to the C-2 epimer of a-tocopherol. Both the General Assembly and the Gouncil of the International Union of Nutritional Sciences (IUNS) and the Council of the American Institute of Nutrition (AIN) have endorsed these proposals. The new IUNS-AIN nomenclature for vitamin E has been adopted as official first action. In addition the official first action method for α-tocopherol and α-tocopheryl acetate, 39.A01–39.A14, has been adopted as official final action.