Vitamin B1 (Thiamine)

Vitamin B1, known scientifically as thiamine, is a water-soluble vitamin that functions as an essential cofactor for several enzymes involved in carbohydrate metabolism and neural function. Its primary purpose is to enable the conversion of carbohydrates into ATP, the cellular energy currency, while also supporting the synthesis of neurotransmitters and myelin maintenance in the nervous system.

• Thiamine (C₁₂H₁₇N₄OS⁺·Cl⁻) is a pyrimidine-linked thiazole derivative.
• IUPAC name: 3-[(4-amino-2-methylpyrimidin-5-yl)methyl]-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride.
• It exists as a positively charged thiazolium ring paired with a chloride counter-ion in the common salt form.
• Key structural features: a thiazolium ring (electron-rich heterocycle) linked via a methylene bridge to a pyrimidine ring; a positively charged nitrogen in the thiazolium confers water solubility.
• The molecule has a pKa of ≈4.6 (acidic) and ~9.5 (basic), making it highly soluble in aqueous media (≈1 g/100 mL at 25 °C).
• The active cofactor, thiamine-pyrophosphate (TPP), adds two phosphate groups (C₁₂H₁₇N₄O₁₄P₂⁻) via ATP-dependent phosphorylation.

• Natural thiamine is abundant in whole grains (especially fortified wheat), legumes, nuts, and pork.
• Commercially, thiamine is primarily produced via microbial fermentation (e.g., Bacillus subtilis or Saccharomyces cerevisiae) followed by purification and crystallization into thiamine hydrochloride or mononitrate.
• Synthetic routes (chemical synthesis from thiazole and pyrimidine precursors) are also used but are less common due to higher cost.
• For supplements, high-purity (>99 %) thiamine hydrochloride is the standard, with GMP-certified manufacturers required to test for heavy metals, microbial contamination, and potency.
• Benfotiamine, a lipid-soluble derivative, is produced by esterification of thiamine with a fatty acid (e.g., benzoic acid) to improve intestinal absorption.
• Quality considerations include verification of the thiazolium-pyrimidine backbone via HPLC and confirmation that no residual fermentation by-products (e.g., endotoxins) remain.