University of Amsterdam scientists discovered a new class of molecules, called ‘quasi catenanes’. These pretzel-like molecules consisting of two molecular rings ‘oppositely’ coupled at a central carbon atom.
Senior author Prof. Jan van Maarseveen and colleagues, said, the new discovery is an important step toward synthesis of lasso peptides, new molecules with a potential use as medicines.
Lasso peptides are small proteins that, consist of a molecular ‘loop’ around a molecular ‘rope’. They were first isolated from bacteria at the turn of the current century.
Recent studies reveal lasso peptides are quite common in the realm of bacteria. Their biological function acts as an antibiotic against other micro-organisms, which makes them a new potent class of antibiotics.
The fact that 15 years after the discovery of lasso-peptides synthetic chemists have not yet been able to develop a strategy leading to their unique molecular architecture underpins the complexity of these molecules.
Scottish chemist Sir Fraser Stoddart shared the Nobel prize for chemistry last year for distinguishes lasso peptides from rotaxanes.
However, this is impossible for lasso peptide synthesis, researchers used a different approach, forcing the loop to close in the right place around the rope.
This turned out to be quite an undertaking. But, finally researchers managed to create a molecular scaffold assisting the synthesis in such a way that the loop correctly forms around the rope.
The new synthesis method is a major step forward in the synthetic route towards functional lasso peptides. To demonstrate the power of their method, the scientists applied the force both ends of the rope to form a second loop.
This resulted in the synthesis of a whole new class of pretzel-like molecules that the Amsterdam researchers coined quasicatenanes.
More information: [Nature]