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|Section2= |Section6= }} Thiamine, thiamin or vitamin B1 ( ), named as the "thio-vitamine" ("sulfur-containing vitamin") is a vitamin of the B complex. First named ''aneurin'' for the detrimental neurological effects if not present in the diet, it was eventually assigned the generic descriptor name vitamin B1. Its phosphate derivatives are involved in many cellular processes. The best-characterized form is thiamine pyrophosphate (TPP), a coenzyme in the catabolism of sugars and amino acids. In yeast, TPP is also required in the first step of alcoholic fermentation. All living organisms use thiamine, but it is synthesized only in bacteria, fungi, and plants. Animals must obtain it from their diet, and thus, for humans, it is an essential nutrient. Insufficient intake in birds produces a characteristic polyneuritis. In mammals, deficiency results in Korsakoff's syndrome, optic neuropathy, and a disease called beriberi that affects the peripheral nervous system (polyneuritis) and/or the cardiovascular system. Thiamine deficiency has a potentially fatal outcome if it remains untreated. In less severe cases, nonspecific signs include malaise, weight loss, irritability and confusion. The stable and non-hygroscopic salt thiamine mononitrate is the vitamer used for flour and food fortification. Thiamine is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system. ==Chemical properties== Thiamine is a colorless organosulfur compound with a chemical formula C12H17N4OS. Its structure consists of an aminopyrimidine and a thiazole ring linked by a methylene bridge. The thiazole is substituted with methyl and hydroxyethyl side chains. Thiamine is soluble in water, methanol, and glycerol and practically insoluble in less polar organic solvents. It is stable at acidic pH, but is unstable in alkaline solutions.〔〔Tanphaichitr V. Thiamin. In: Shils ME, Olsen JA, Shike M et al., editors. ''Modern Nutrition in Health and Disease''. 9th ed. Baltimore: Lippincott Williams & Wilkins; 1999〕 Thiamine, which is a N-heterocyclic carbene, can be used in place of cyanide as a catalyst for benzoin condensation.〔http://www.umsl.edu/~orglab/pdffiles/multistp.pdf〕〔http://www.stpaulsschool.org.uk/resource.aspx?id=136714〕 Thiamine is unstable to heat, but stable during frozen storage. It is unstable when exposed to ultraviolet light〔 and gamma irradiation.〔Luczak M, Zeszyty Probi PostepoLc Vauh Roln 1968;80,497; ''Chem Abstr'' 1969;71,2267g〕〔Syunyakova ZM, Karpova IN, ''Vop Pitan'' 1966;25(2),52; ''Chem Abstr'' 1966;65,1297b〕 Thiamine reacts strongly in Maillard-type reactions.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Thiamine」の詳細全文を読む スポンサード リンク
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