Recent research results have challenged conventional understanding of the oxidation of the "radical scavenger", vitamin E. Cutting-edge analysis methods have revealed that the intermediates commonly believed to be involved in the process do not occur.
This surprising finding has been systematically documented and published as part of a project supported by the Austrian Science Fund FWF. The new findings are also extremely important for a follow-up project that is focusing on the synthesis of "super antioxidants" based on a polymeric vitamin E.
Vitamin E is one of the most important naturally occurring antioxidants, and has become widely known as a "radical scavenger" and anti-ageing product. It is perhaps precisely this high profile that has caused scientific interest in vitamin E to focus on optimizing its usage, while aspects relating to the basic chemistry have received less attention. However, in their work to develop new potential applications, chemists are revisiting these basics and are radically rewriting a great deal of accepted teaching as they do so.
One such chemist is Prof. Thomas Rosenau from the Department of Chemistry at the University of Natural Resources and Applied Life Sciences in Vienna.
During their work, he and his team closely analyzed the chemical processes involved in the one-electron oxidation of alpha-tocopherol (the main component of vitamin E), which conventional understanding dictates is proceeding via certain intermediates, known as C-centred radicals with an o-quinone methide (oQM) structure. However, the results produced by Prof. Rosenau's team entirely disprove this theory.
Prof. Rosenau explains: "In principle, oQMs have low stability and a short lifespan. This makes it extremely difficult to demonstrate their presence and investigate them. However, we succeeded in significantly improving the stability of oQMs and extending their lifespan to up to 20 minutes. This enabled us to monitor oQMs directly in our analysis work on reaction processes."
Because extreme caution should be exercised when refuting accepted teaching, Prof. Rosenau¹s team ensured that all analyses were founded on a solid basis. A number of independent analytical methods were employed to confirm the team¹s results. These included electron paramagnetic resonance spectroscopy in liquid and solid phases, electron spin resonance spectroscopy, mass spectroscopy, the isotopic labelling of special derivatives, investigation of reaction kinetics and the development of computer models.