An interdisciplinary team of scientists has used dried St. John’s Wort (genus Hypericum) flowers as an active catalyst in green chemistry applications, specifically photochemical reactions.
The research groups, led by botanist Professor Stefan Wanke and chemist Professor Jan J Weigand, originally wanted to synthesise graphene-like 2D structures from natural products. In order to meet this goal, the team use hypericin, a compound of St. John’s Wort, as a template and starting material. During the investigations, the team discovered that hypericin efficiently catalyses photochemical reactions. Weigand then decided to use the dried flowers of St. John’s Wort, which contains hypericin, as a catalyst in green chemistry applications.
Weigand said: “The chemistry of natural substances and especially the background of botany were completely new to us. The exciting results that came out of it are all the more gratifying. The interdisciplinary project shows how important it is in science to think outside the box.”
As published in the journal Green Chemistry, the team is following a current trend in modern synthetic chemistry to include sustainable aspects. The search for sustainable, renewable, and environmentally friendly photoredox catalysts is proving to be extremely challenging.
According to the team from the School of Science at TU Dresden, the plant compound hypericin, a secondary metabolite from St. John’s Wort, can be used as the active compound in chemical reactions without the need for prior chemical processing, a process that has now been patented by the researchers.
Wanke added: “Although the research project started with a good idea, bringing it to life was not entirely trivial, as the two working groups first had to ‘get to know’ each other. Our research fields and methods used were far apart. But soon the first unusually exciting results emerged. Everyone involved learned a lot. We would like to continue the research, but the funding is still missing.”