Tauroursodeoxycholic acid
[CAS# 14605-22-2]

Identification

• Classification: Biochemical >> Chinese herbal medicine ingredients
• Name: Tauroursodeoxycholic acid
• Synonyms: 2-[[(4R)-4-[(3R,5S,7S,8R,9S,10S,13R,14S,17R)-3,7-dihydroxy-10,13-dimethyl-2,3,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl]pentanoyl]amino]ethanesulfonic acid
• Molecular Formula: C₂₆H₄₅NO₆S
• Molecular Weight: 499.70
• CAS Registry Number: 14605-22-2
• EC Number: 987-160-3
• SMILES: C[C@H](CCC(=O)NCCS(=O)(=O)O)[C@H]1CC[C@@H]2[C@@]1(CC[C@H]3[C@H]2[C@H](C[C@H]4[C@@]3(CC[C@H](C4)O)C)O)C

Properties

• Density: 1.2±0.1 g/cm³ Calc.^*
• Index of refraction: 1.552 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05 Danger
• Risk Statements: H314-H318
• Safety Statements: P260-P264-P264+P265-P280-P301+P330+P331-P302+P361+P354-P304+P340-P305+P354+P338-P316-P317-P321-P363-P405-P501

Discovery and Applications

Tauroursodeoxycholic acid (TUDCA) is a taurine-conjugated form of ursodeoxycholic acid (UDCA), a secondary bile acid formed in the human intestine by microbial metabolism of primary bile acids. TUDCA is an endogenous bile acid found in small quantities in humans but more abundantly in bears, where it was first isolated from bear bile during traditional medicinal practices in East Asia. The discovery of TUDCA traces back to ancient times, with historical use in traditional Chinese medicine for treating liver and gallbladder disorders. Its isolation and chemical characterization were achieved through progressive improvements in chromatography and spectroscopic methods in the mid-20th century.

The molecular structure of TUDCA comprises a steroid backbone with hydroxyl groups at the 3α, 7β positions and a taurine group conjugated to the carboxylic acid side chain at the 24-position. The presence of the taurine moiety increases the hydrophilicity and solubility of the molecule compared to unconjugated bile acids. This conjugation also impacts its pharmacokinetics and biological activity.

TUDCA has been studied extensively for its cytoprotective and anti-apoptotic properties, especially within the context of liver diseases. It has shown efficacy in improving bile acid homeostasis and protecting hepatocytes against bile acid-induced toxicity. In clinical applications, TUDCA has been used as an alternative or adjunct therapy to UDCA in treating cholestatic liver diseases, including primary biliary cholangitis. It has also been evaluated for potential benefits in hepatic steatosis, non-alcoholic fatty liver disease, and viral hepatitis.

Beyond hepatology, TUDCA has demonstrated neuroprotective properties in preclinical models. Studies have shown that TUDCA can cross the blood-brain barrier and exert protective effects in models of neurodegenerative diseases such as amyotrophic lateral sclerosis, Parkinson’s disease, and Alzheimer’s disease. The mechanism is believed to involve inhibition of endoplasmic reticulum stress and reduction of mitochondrial dysfunction, which are common features of neurodegeneration.

In metabolic disease contexts, TUDCA has attracted interest for its potential in improving insulin sensitivity and glucose metabolism. It has been reported to enhance endoplasmic reticulum function and alleviate insulin resistance in obesity-related conditions. These findings have led to increasing interest in TUDCA as a therapeutic candidate for type 2 diabetes mellitus and associated metabolic disorders.

TUDCA has also been investigated in ophthalmology, where it has been found to protect photoreceptor cells in models of retinal degeneration. Similarly, its anti-apoptotic and anti-inflammatory effects have suggested applications in cardiovascular research and autoimmune disorders.

Despite the wide range of applications observed in experimental models, human clinical data on TUDCA are relatively limited. While it is used as a dietary supplement in some countries, regulatory approvals for therapeutic use vary globally. Its pharmacological profile, safety, and therapeutic window continue to be explored in clinical trials.

The therapeutic versatility of TUDCA reflects its ability to influence multiple cellular pathways including mitochondrial integrity, oxidative stress modulation, protein folding, and apoptosis regulation. As such, TUDCA remains a compound of interest in translational medicine, particularly for diseases involving organelle stress and cell death.

References

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DOI: 10.1016/j.bmcl.2011.11.030

2005. Anxiolytic agent, dihydrohonokiol-B, recovers amyloid beta protein-induced neurotoxicity in cultured rat hippocampal neurons. Neuroscience Letters, 384(1-2).
DOI: 10.1016/j.neulet.2005.04.081

2001. Confirmation of the anxiolytic-like effect of dihydrohonokiol following behavioural and biochemical assessments. The Journal of Pharmacy and Pharmacology, 53(5).
DOI: 10.1211/0022357011775848