Thiamine, also known as aneurin or vitamin B1, belongs to the class of organic compounds known as thiamines. Thiamines are compounds containing a thiamine moiety, which is structurally characterized by a 3-[(4-Amino-2-methyl-pyrimidin-5-yl)methyl]-4-methyl-thiazol-5-yl backbone. Thiamine exists in all living species, ranging from bacteria to plants to humans.  Thiamine biosynthesis occurs in bacteria, some protozoans, plants, and fungi. Thiamine is a vitamin and an essential nutrient meaning the body cannot synthesize it, and it must be obtained from the diet. It is soluble in water and insoluble in alcohol. Thiamine decomposes if heated. Thiamine was first discovered in 1897 by Umetaro Suzuki in Japan when researching how rice bran cured patients of Beriberi. Thiamine was the first B vitamin to be isolated in 1926 and was first made in 1936. Thiamine plays a key role in intracellular glucose metabolism and it is thought that thiamine inhibits the effect of glucose and insulin on arterial smooth muscle cell proliferation. Thiamine plays an important role in helping the body convert carbohydrates and fat into energy. It is essential for normal growth and development and helps to maintain proper functioning of the heart and the nervous and digestive systems. Thiamine cannot be stored in the body; however, once absorbed, the vitamin is concentrated in muscle tissue. Thiamine has antioxidant, erythropoietic, cognition-and mood-modulatory, antiatherosclerotic, putative ergogenic, and detoxification activities. Natural derivatives of thiamine, such as thiamine monophosphate (ThMP), thiamine diphosphate (ThDP), also sometimes called thiamine pyrophosphate (TPP), thiamine triphosphate (ThTP), and adenosine thiamine triphosphate (AThTP), act as coenzymes in addition to performing unique biological functions. Thiamine deficiency can lead to beriberi, Wernicke‚ÄìKorsakoff syndrome, optic neuropathy, Leigh's disease, African seasonal ataxia (or Nigerian seasonal ataxia), and central pontine myelinolysis. In Western countries, thiamine deficiency is seen mainly in chronic alcoholism. Thiamine supplements or thiamine therapy can be used for the treatment of a number of disorders including thiamine and niacin deficiency states, Korsakov's alcoholic psychosis, Wernicke-Korsakov syndrome, delirium, and peripheral neuritis. In humans, thiamine is involved in the metabolic disorder called 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency. Outside of the human body, Thiamine is found in high quantities in whole grains, legumes, pork, fruits, and yeast and fish. Grain processing removes much of the thiamine content in grains, so in many countries cereals and flours are enriched with thiamine.