Chemists present new reaction with promising applications

The image shows a laser experiment in a laboratory.
Image: Dirk Guldi

The photocatalytic process for the cleavage of disulfides is fast and biocompatible

Scientists led by Prof. Dr. Dirk Guldi from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and Prof. Dr. Frank Glorius and Michael Teders from the Westfälische Wilhelms-Universität Münster (WWU) have presented a new chemical reaction that could be of interest for investigating and manufacturing active substances. The new reaction leads to the cleavage of bonds between two sulfur atoms. Chemists use light-controlled catalysis (photocatalysis) to achieve this effect. Their findings have been published in the journal “Nature Chemistry” (online in advance).

Thanks to their new insights, the scientists are able to produce a rapid and accurate reaction; an example of ‘click chemistry’. The symmetrical cleavage of disulfides – molecules with bonds between two sulfur atoms – results in products that can be used for various applications. ‘These thiyl-sulfur radicals can be used in the production of drugs, pesticides or polymers,’ says Frank Glorius, Organic Chemistry Institute, WWU.

To enable the reaction, the scientists from Münster use a special photocatalyst molecule that absorbs and stores the energy of visible light and then transfers it to a molecule directly involved in the reaction. This process, in which the molecules transfer electrons to each other, is called energy transfer. In contrast to unidirectional electron transfer from the photocatalyst, this process is not very common in light-controlled photocatalysis. Dirk Guldi’s group (FAU) investigated the molecular mechanism of energy transfer using ultrafast spectroscopy. During this process, very short laser pulses make the molecular properties and changes during a chemical reaction visible.

An interesting feature of the new reaction for biochemists is its biocompatibility. This means that it can potentially take place in living cells without causing damage. Conversely, the reaction is not disturbed by cell components. This makes the reaction interesting for applications in molecular labelling chemistry which involves making biomolecules visible in living cells in order to to observe biological processes. The biocompatibility of the energy transfer method was evaluated at WWU by the research groups led by Frank Glorius and biochemist Andrea Rentmeister, professor in the “Cells in Motion” (CiM) cluster of excellence, by developing and applying a novel screening method. The scientists added numerous biomolecules occurring in the cell individually to the reaction method in order to study their effects. They also examined the effects of all biomolecules present in the cell on the reaction.

The research was funded by the German Research Foundation (DFG).

Further information:

Prof. Dr. Dirk Guldi
Phone +49 9131 8527340