Thiamine

1 Definition

Thiamine is a water-soluble vitamin of B-complex. In the human body it has an energy releasing function which in deficiency symptoms especially effects the central nervous system.

2 Structure

Thiamine consists of a pyrimidine- and thiazole ring liked by a methylene bridge.

3 Metabolically active form

The metabolically active form of thiamine is thiamine pyrophosphate (TPP). TPP is synthesised by the transfer of a pyrophosphate group from ATP to thiamine. ATP is cleaved into AMP by thiamine pyrophosphate synthetase and the released pyrophosphate is added to thiamine.

4 Biochemichal role

TPP acts as coenzyme in two important metabolic pathways:

• Oxidative decarboxylation of α-keto acids (important reaction in the energy metabolism of most cells)
• Pentose phosphate pathway

5 Requirement

Adults require about 1-1.5mg/day

6 Deficiency

Vitamin B1 deficiency leads to a disease called beri-beri with two major formes:

• Wet beri-beri
• Dry beri-beri (Wernicke-Korsakoff syndrome)

7 Source

Tiberiu Nistor - Basic in descriptive biochemistry