29. April 2015 Breakthrough in basic research: Kiel researchers discover new means against cancerous tumours

Researchers at the Institute of Pharmacy at Kiel University have developed chemical compounds which have demonstrated strong effects on tumours. The so-called "aromatic heterocyclic compounds" are also easy and efficient to produce. The working group around Professor Bernd Clement has now published its findings in the renowned research journal "Chemistry - A European Journal". Properties and benefits
Initials tests with one of the chemical structures developed in Kiel were performed in the National Cancer Institute in Bethesda, USA, on 60 different tumour cell lines. They discovered that the Kiel structure inhibited tumour growth to a similar extent as previously approved cancer medicines - or even exceeded the effectiveness of these medicines.

In comparison with other methods to produce comparable substances, the one developed in Kiel has a significant benefit, however, as Bernd Clement, Professor of Pharmacy, explains: "The compound class is extremely easy to produce using the method we developed, 'Clement and Weide Cyclisation'. Other methods are much more complex and contain several individual steps. If this substance is to be used as a medicine in the future, then we can hope for a much more cost-effective production than today."

An added advantage of the newly found method is in the high level of variability of the resulting chemical structures, says doctoral candidate Tamara N. Steinhauer: "We are able to perform structural variations on a certain position without making production more complicated." In the future, therefore, this discovery could lead to the development of many more structural classes. Steinhauer says: "You only need two components, which are conveniently available cheaply and on a commercial basis, and you convert them in a chemical reaction."

Production
"The discovery is based on a method of synthesising heterocyclic compounds, developed and patented in our working group", says Steinhauer. Heterocyclic compounds are chemical compounds consisting of at least two different elements and which form ring structures. Steinhauer says: "By exchanging one of the two components brought to a reaction in the synthesis, we have produced a completely new class of compound which has not yet been described in specialist literature."

Within the chemical synthesis, two small simple molecules in a 2:1 ratio are brought to a reaction in a three-component-reaction by adding a base substance, whereby the complex heterocyclic structure can be constructed. In practice, the initial substances and the base substance are stirred together into a solution for one hour at 0° C and then for an hour at 8 °C. The product is then obtained via simple hydrolysis. The reaction solution is poured over ice water, causing the product to precipitate so it can then be isolated.

Tests and further development
Professor Clement now wants to further investigate the substances: "Three derivatives from the new class of compound are described in our publication. However, the flexible method means that several different derivatives can be produced and then tested for their effects against tumours. This work will be the subject of another publication. Before one of these substances can be applied, however, much work must be done in terms of preclinical development."


Original publication:
“Triggering the Directional Selectivity of a Ring-Closure Reaction Leads to Pyridoazacarbazoles with Anticancer Properties.” Chemistry – A European Journal, (T. N. Steinhauer et al., Chem. Eur. J. 2015, 21, 6668-66672, DOI: 10.1002/chem.201581861)