The location of metal complexes within living cancer cells has been accurately determined using Raman microscopy. The researchers have thus gained new insights into the mechanism of action of metal-containing drugs, to which they ascribe great potential capacities, e.g. in the treatment of cancer. These findings are of fundamental significance and are thus featured as a VIP (very important paper) in the current edition of Angewandte Chemie.

The two research teams working under the auspices of Dr Ulrich Schatzschneider and Professor Nils Metzler-Nolte from the Ruhr University, Bochum, Germany, synthesised metal compounds that can be effective in the treatment of cancer and infectious diseases. Professor Metzler-Nolte pointed out that well over 50% of all chemical elements are metals. It is thus all the more surprising that the drug portfolio—with a few exceptions—includes almost bioactive metal complexes despite the fact that these are just as active in cellular models of cancer as the best organic compounds. During traditional research, a drug molecule is synthesised to recognise a known target molecule in the cell, whereas there is almost no data available on the mechanism of action of such metal compounds. The researchers surmise that entirely new mechanisms of action could possibly be precisely due to the special properties of metal compounds. It is thus all the more important that these modes of action be clarified to ensure that new active ingredients with improved properties can be produced.

Raman microscopy has now enabled the researchers to get closer to this target. The scientists made use of the fact that the metal compounds investigated have characteristic vibrations in a frequency range that is not occupied by the other molecules. Professor Martina Havenith and her research group, which has developed new physical methods of spectroscopic investigation, analysed the fingerprint within the cell. Her colleagues were able to the view the absorption of the metal compound, observing that it is enriched in the nucleus of the cell after a few hours. In contrast to the common methods used, the researchers did not have to destroy the cells for their investigation. They also did not need any further labels such as marker molecules. The localisation of the compound in the nucleus of the cell supplies these synthesis chemists with important information on the mechanism of action and possible improvements in the compound.

The importance of these results is shown by their designation as a VIP (very important paper) in Angewandte Chemie, which is only the case if all of the anonymous experts selected by the editorial office are unanimously of this opinion.