Lead
We are looking for an alternative to the important natural antibiotic colistin. With this in mind we are systematically exploring related structures by chemically synthesising those that do not occur naturally.

Lay summary

When nothing else works, maybe colistin will. Nowadays this antimicrobial peptide of natural origin is used as the last resort against many multiresistant germs. Yet it can have considerable side effects, and there are now bacteria that are resistant to it. Other peptides offer particular promise in the search for alternatives to this important substance. We have already discovered some that are active against multiresistant bacteria by systematically investigating peptides related to colistin that do not occur naturally. They have never been studied before because they are not natural substances. We are now optimising these artificial peptides, investigating their mechanism of action and assessing which might be useful for medical purposes.

Background
We are using the chemical space approach. This term refers to the total number of existing molecules that can be used as medicines. Nowadays the chemical space can be explored efficiently using bioinformatic methods and automated chemical synthesis, and this is being done in many laboratories. We have expanded this approach to include new molecules that are not found in nature and which have therefore not been studied previously.

Aim
Our goal is to identify previously unknown peptides whose antibiotic action and favourable pharmacological profile may potentially make them suitable for use in human medicine. The intention is to put these peptides into clinical development.

Relevance
New antibiotics are important for public health. One particular advantage of our peptides is that they are easy to synthesise and can therefore be optimised. They are also easy to patent because they are chemically unique, which makes them a very interesting proposition for clinical development.