TUDCA (Tauroursodeoxycholic Acid)

Tauroursodeoxycholic acid (TUDCA) is a naturally occurring, taurine‑conjugated bile acid derived from ursodeoxycholic acid (UDCA). It is most widely recognized for its cytoprotective properties, particularly its ability to stabilize cellular membranes and mitigate endoplasmic‑reticulum (ER) stress, making it a popular nutraceutical for liver, neurological, and metabolic support.

• TUDCA (C₂₆H₄₅NO₆) is the taurine conjugate of ursodeoxycholic acid.
• IUPAC name: (3α,7β‑dihydroxy‑5β‑chol-24‑yl) taurine.
• It is a secondary bile acid with a 24‑carbon steroid backbone (four fused rings) bearing two hydroxyl groups at C‑3α and C‑7β, a carboxyl group at C‑24 that is amide‑linked to the amino‑sulfonic acid taurine.
• The molecule is amphipathic: the hydrophobic steroid core confers membrane‑binding capacity, while the polar taurine moiety confers high water solubility (≈ 5 g/L at 25 °C).
• The pKa of the sulfonic acid is ~1.5, making the molecule negatively charged at physiological pH, facilitating interaction with bile‑acid transporters (ASBT, NTCP).
• Its molecular weight is 514.7 g/mol, and it is stable in acidic pH but susceptible to oxidation at the 7‑hydroxyl in the presence of strong oxidants.

• Commercial TUDCA is obtained primarily from two routes:
  • (1) Extraction from the bile of healthy pigs or cattle, where UDCA is isolated and subsequently conjugated to taurine using enzymatic or chemical synthesis
  • (2) Synthetic production via chemical synthesis of the steroid core followed by taurine conjugation, which yields a highly pure (>98 %) product.
• High‑quality supplements typically use pharmaceutical‑grade, GMP‑certified processes that remove residual animal proteins, endotoxins, and heavy metals.
• Authenticity can be verified by HPLC‑UV or LC‑MS showing a single peak at the expected retention time and a mass‑to‑charge ratio of 514.2 m/z.
• For consumers, third‑party testing (e.g., USP, NSF) and a clear certificate of analysis are essential to ensure purity and avoid contamination with bile‑acid impurities that could provoke adverse effects.