N-Acetyltaurine
N-Acetyltaurine is an endogenous metabolite. Biochemically, N-acetyltaurine is formed as a result of an acetylation of taurine. The main substrate for this reaction is acetate. An increase of endogenous N-acetyltaurine concentrations was observed after the consumption of alcohol and after extended physical activity.
History
N-Acetyltaurine was first mentioned in 1990 as a compound in the droplets of the orb spider's viscid spiral. Based on its high hygroscopicity, N-acetyltaurine is an important ingredient which ensures the spider web's flexibility.As a biomarker for ethanol metabolism, N-acetyltaurine was first mentioned in a mice study in 2012. Another study in 2015 focused on the effect of endurance training on an increase in N-acetyltaurine concentrations. The first study focusing on the forensic context of alcohol biomarker analysis in human urine was published in 2016. One year later, in 2017 an evaluation of N-acetyltaurine as an alcoholmarker in human blood followed.
Significance as an alcohol marker
N-Acetyltaurine is a direct alcohol biomarker which represents the oxidative pathway of ethanol metabolism. Other direct alcohol biomarkers such as fatty acid ethyl esters, ethyl glucuronide, ethyl sulfate, and phosphatidylethanol reflect the non-oxidative pathway of alcohol metabolism, based on conjunction reactions.The fact that N-acetyltaurine is an endogenous metabolite reduces its significance as an alcohol biomarker: A distinction between endogenous N-acetyltaurine concentrations and alcohol induced concentrations is necessary.
During a drinking study with a target blood alcohol concentrations of 0.8 g/kg, an alcohol induced concentration of N-acetyltaurine which was about ten folds higher than the endogenous concentration was observed. In blood the alcohol induced increase was only twofold. Based on these observations, it was concluded that N-acetyltaurine is excreted very efficiently by the kidney.