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# 3. Detailed Definition of Thiamine

This article is currently under construction

Chemically, **thiamine (C₁₂H₁₇N₄OS)** consists of two heterocyclic rings: a substituted pyrimidine and a thiazole, connected by a methylene bridge. It is a **water-soluble vitamin** and is unstable in alkaline conditions and sensitive to heat and oxidative agents.

In the body, thiamine is rapidly phosphorylated to its biologically active form, **thiamine pyrophosphate (TPP)**—also called **thiamine diphosphate (TDP)**. Other important derivatives include:

* **Thiamine monophosphate (TMP)** – An intermediate in thiamine metabolism.
* **Thiamine triphosphate (TTP)** – Found in nervous tissue; may play roles in membrane function and signal transmission.
* **Adenosine thiamine triphosphate (AThTP)** – Observed in stress responses in bacteria and mammals.