Thiamin vitamin chemical properties

In 1936, a growth-promoting factor termed vitamin B was isolated from bovine (cow) milk. There are now several different types of vitamin B known and chemically characterized, and they are collectively described as B complex vitamins because of relative similarities in their properties, physiological functions, and distribution in natural resources. Mostly recognized as coenzymes, the eight B complex vitamins currently include Bj (thiamine), B2 (riboflavin), niacin (nicotinamide), B (pyridoxine), pantothenic acid, biotin, B22 (cyanocobalamin), and folacin (folic acid). 

Most physiologically active compounds owe their biological properties to the presence of heteroatoms, mainly in the form of heterocydes. A majority of the known natural products are heterocyclic. It is therefore not surprising that more than half the published chemical literature deals with such compounds—then-synthesis, isolation, and interconversions. Indeed, we have already encountered many examples—the cyclic ethers (Section 9-6), acetals (Sections 17-8, 23-4, and 24-8), carboxylic acid derivatives (Chapters 19 and 20), and amines (Chapter 21). The bases in DNA, whose sequence stores hereditary information, are heterocydes (Section 26-9) so are many vitamins, such as Bi (thiamine. Real Life 23-2), B2 (riboflavin. Real Life 25-3), Bg (pyridoxine), the spectacularly complex B12, and vitamins C and E (Section 22-9). The structures of vitamins Bg and B12, as well as additional examples of heterocyclic systems and their varied uses, are depicted here. 

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