Cholesterol is a pivotal precursor of diverse physiologically important substances, such as fat-soluble vitamins, bile acids and steroid hormones, beside its texturing function in cell membranes. Biosynthesis of these substances in vivo results from specific oxidation and rearrangement of the sterol backbone of cholesterol. Intermediate substances, so called oxysterols, formed by enzymatic and non-enzymatic oxidation reactions possess versatile bioactivities themselves which are not fully understood by now.

Maria Fedorova, Leipzig University, Germany, and colleagues used amperometric flow-through electrochemical oxidation to create oxidation products of cholesterol in short reaction times. The electrochemical oxidation mimics naturally occurring oxidation reactions.

The team produced various oxysterols – nine of which are known to be generated in vivo by enzymatic and non-enzymatic processes. But they also found not yet identified oxysterols which show exactly the same retention-times in liquid chromatography as compounds observed from cell extracts, indicating their possible biological significance. Their specific biological function, however, has yet to be determined in cell model systems.

• Electrochemical oxidation of cholesterol: An easy way to generate numerous oxysterols in short reaction times,
  Dieter Weber, Zhixu Ni, Daniel Vetter, Ralf Hoffmann, Maria Fedorova,
  Eur. J. Lipid Sci. Technol. 2015.
  DOI: 10.1002/ejlt.201500101