Definition and Nomenclature of the Vitamins

In addition to systematic chemical nomenclature, the vittunins have an ap-peirently illogical system of accepted trivitd names arising from the history of their discovery (Table 1.1). For severed viteunins, a number of chemicedly related compounds show the same biologiced activity, because they are either converted to the same fined active metabolite or have sufficient structured similarity to have the same activity. 

Different chemical compounds that show the seune biologiced activity ene collectively known as vitamers. Where one or more compounds have biological activity, in addition to individual names there is also an approved generic descriptor to be used for all related compounds that show the same biological activity. 

When it was reedized that milk contained more than one accessory food factor, they were neuned A (which was lipid-soluble and found in the cream) emd B (which Wcis water-soluble and found in the whey). This division into fat- cmd water-soluble vitamins is still used, although there is little chemical or nutritioncd rccison for this, apart from some similarities in dietary sources of fat-soluble or water-soluble vitamins. Water-soluble derivatives of vitamins A and K cmd fat-soluble derivatives of several of the B vitamins and vitamin C have been developed for therapeutic use and as food additives. 

As the discovery of the vitamins progressed, it was realized that Factor B consisted of a number of chemically and physiologically distinct compounds. Before they were identified chemically, they were given a logical series of alphanumeric ncunes Bi, B2, and so forth. As can be seen from Table 1.2, a number of compounds were assigned vitamin status, and were later shown either not to be vitcunins, or to be compounds that had already been identified and given other ncUnes. 

A Retinol Visual pigments in the retina Night blindness. 

E Tocopherois Antioxidant, especially in cell Extremely rare - serious 

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Butterworths, 1958) gives the full text of the lUPAC recommendations, containing definitive rules for hydrocarbons, fundamental heterocyclic systems and steroids, with tentative rules for nomenclature in the vitamin B12 field, and a corresponding volume Nomenclature of Inorganic Chemistry has been issued by the same publishers (1959). Nomenclature of biochemistry, inorganic and organic chemistry is also discussed in J. Amer. chem. Soc. 82, 5523-84 (1960). 

International Union of Pure and Applied Chemistry, /. Am. Chem. Soc. 82, 5575-84 (I960) Definitive rules for the nomenclature of amino acids, steroids, vitamins, and carotenoids (lUPAC). 

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