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N-ethyl-tauroursodeoxycholic acid, a novel deconjugation-resistant bile salt analogue


Senior Member
Virginia, USA
Does anyone have any idea to to grab a few grams of this magical chemical? I'm using TUDCA but I always get a little nervous about the idea of deconjugation by bacteria.

The purpose of this study was to investigate the physicochemical/biological properties and the effects of acute administration of N-ethyl-tauroursodeoxycholic acid in bile-fistula rats. In vitro determination of high-performance liquid chromatography mobility, octanol/water partitioning, cholesterol solubilizing capacity, and sensitivity to enzyme deconjugation by bacteria and cholylglycine-hydroxylase were performed. In vivo determination of the following was also performed: (1) maximum secretory rate (SRmax) and choleretic/secretory properties during intravenous (IV) administration; (2) site/extent of absorption, effects on bile flow, lipid secretion, and biotransformations after intraduodenal infusion. N-ethyl-tauroursodeoxycholate has a lipophilicity slightly higher than tauroursodeoxycholate, close to taurocholate, and similar cholesterol solubilizing capacity. Deconjugation of N-ethyl-tauroursodeoxycholate was 3.4 ±2.1% after 72 hours, that of tauroursodeoxycholate was 100% after 24 hours. During IV infusion of 300 nmol/min/ 100 g, biliary secretion of N-ethyl-tauroursodeoxycholic and tauroursodeoxycholic acids averaged 185 ±76 (standard deviation) nmol/min/100 g and 221 ± 77 nmol/min/ 100 g (not significant). Increasing infusion rates caused progressive enhancement of bile flow and bile salt secretion until the SRmax was reached (1,305 ± 240 nmol/min/ 100 g for N-ethyl-tauroursodeoxycholic acid and 3,240 nmol/min/100 g for tauroursodeoxycholate). The two bile salts were similarly choleretic. IV feeding of N-ethyltauroursodeoxycholic promoted a greater lipid secretion than tauroursodeoxycholate. After intraduodenal feeding of 800 μmol, 38.8 ± 14.0% and 43.4 ± 12.4% of the two bile salts were recovered in bile. No unconjugated bile salts nor unusual metabolites were detected. Excluding the distal 30 cm of the ileum, only 2.3 ± 0.7% of N-ethyl-tauroursodeoxycholic and 4.0 ± 2.3% of tauroursodeoxycholic acid was absorbed. N-ethyl-tauroursodeoxycholic is a new, hydrophilic, deconjugation-resistant, synthetic bile salt, which, in acute studies in the rat, behaves as the natural analogue with respect to intestinal and hepatobiliary properties.


Senior Member
I am not aware of this type of TUDCA.

I will have to stress out that according to the Hypothesis i've been discussing not everything fits to everyone. So TUDCA may be very beneficial to some but to others it may not be.

Unfortunately Bile Acids metabolism is a very tricky subject and an expert is needed.