Thiamine

• Thiamine
• Aneurin
• Antineuritisches vitamin
• Antiberiberifaktor
• 3 - ( (4- amino-2- methyl-5- pyrimidinyl) methyl) - 5 - (2 -hydroxyethyl) - 4- methylthiazolium chloride

• C12H17ClN4OS (chloride )
• C12H18Cl2N4OS (hydrochloride)

• 59-43-8
• 67-03-8 (hydrochloride)

A11DA01

248 ° C ( decomposition)

Hydrochloride

• 214 mg · kg -1 · 30W -1 (human, TDLo, multiple routes of exposure )
• 301 mg · kg -1 (mouse, LD50, subcutaneous ) Template: Infobox Vitamin/LD50 not empty

Thiamin, vitamin B1, or aneurine is a water-soluble vitamin of the B complex of a weak, but characteristic odor and is indispensable especially for the function of the nervous system. If the vitamin B1 is no longer supplied to the body for about 14 days, the reserves are 50% depleted. It is known locally as the mood vitamin.

Chemical structure

Thiamine consists of two ring systems which are linked by a methylene bridge: a pyrimidine and thiazole.

Function

Thiamine is absorbed in the intestine via the active Thiam intra Sporter and present in high concentrations by diffusion. There are rare hereditary deficiency diseases these proteins. When thiamine responsiblen, megaloblastic anemia ( TRMA ) occurs by mutations in the SLC19A2 gene to inoperability of the active Thiamintransporters. This allows the in the food present in low concentrations of thiamine not be added sufficiently. This leads to the characteristic clinical picture of TRMA with type 1 diabetes mellitus, deafness, megaloblastic anemia of all cell lines and cause serious heart disorders. If left untreated, the TRMA to death. By administering a high dose of thiamine can be absorbed from the intestine by diffusion enough thiamine.

Thiamine itself is not used in the body. Using the enzyme Thiaminpyrophosphokinase it is first to thiamine pyrophosphate (TPP, also thiamine diphosphate, TDP) converted. In that the biologically active form, it is a coenzyme of the pyruvate dehydrogenase E1, the α -ketoglutarate dehydrogenase, the α -keto acid dehydrogenase and transketolase.

Losses in food

Thiamine is heat sensitive, it is destroyed by cooking. It is water soluble, thereby losing some of the cooking water while cooking in water. In raw fish and ferns the enzyme thiaminase is included, which breaks down thiamine and thus destroyed.

Occurrence

Per 100 g of the following foods, the amounts of thiamine are given according to the Federal Food Key (BLS ) includes:

• 2.01 mg in wheat germ
• 1.9 mg in sunflower seeds, fresh
• 1.0 mg pressed in yeast,
• 0.44 mg in soybeans, fresh
• 0.4 mg in sesame roasted,
• 0.40 mg in Kamut
• 0.35 to 0.46 mg in whole grains (wheat, barley, maize, rice - not heated )
• 0.23 mg in pork (medium fat ), fresh
• 0.3 mg in Teff
• 0.3 mg in Peas, green, fresh
• 0.28 mg in macadamia nuts, fresh
• 0.19 mg in dandelion, fresh
• 0.17 mg in oyster mushroom, fresh
• 0.154 mg in beans, white, cooked
• 0.15 mg in oatmeal, raw
• 0.11 mg in poultry, cooked
• 0.07 mg in jacket potatoes, cooked

Demand ( supply recommendation)

• Infants (up to 12 months): 0.2-0.4 mg / day
• Children (1-15 years): female: 0.6-1.1 mg / day
• Male: 0.6-1.4 mg / day

• Pregnant (4th month): 1.2 mg / day
• Breastfeeding: 1.4 mg / day

In South America Thiamingabe is often used to travel to the Amazon as a defense against mosquitoes, since mosquitoes would reject the smell. The protective effect is individual and is doubted by many authors.

Deficiency ( hypovitaminosis )

Symptoms:

• Disorders of carbohydrate metabolism and nervous system (including polyneuropathy )
• Irritability and depression
• Drowsiness, blurred vision, loss of appetite, lack of concentration, muscle atrophy
• Anemia (anemia)
• Frequent headaches
• Memory impairment ( Korsakoff's syndrome), confusion states
• Heart failure, edema, tachycardia, low blood pressure, shortness of breath ( dyspnea)
• Decreased production of antibodies in infections
• Disturbed energy production
• Weak muscles ( especially the calf muscles )
• Diseases: Man: beriberi, Wernicke's encephalopathy, Strachan syndrome
• Animals: Thiamine deficiency encephalopathy cat, Zerebrokortikalnekrose, Chastek paralysis

Consequences of an overdose ( hypervitaminosis )

Thiamine has a wide therapeutic range. To view animal experimental findings in rats that even a 100-fold higher than the daily requirement dose was tolerated over three generations without side effects. After parenteral administration ( = injection therapy ) in the muscle or into a vein, however, some severe hypersensitivity reactions to respiratory distress and shock conditions have been described in single cases. Because of these allergic reactions vitamin B1 should be given parenterally only in exceptional cases, oral therapy of choice for vitamin B1 substitution is the fat-soluble and therefore ideal tissue common prodrug benfotiamine thiamine.

History