Seven of the ten most commonly used drugs contain chiral drugs. These are molecules that appear in the form of right or left hands. In the chemical synthesis process, the two forms usually occur in equal parts and must be separated afterwards because the chirality determines the action of the agent in the body. Goethe University physicists have now successfully used lasers to make right-handed or left-handed molecules.
"In pharmacy, it is a dream to be able to use light rather than wet chemistry to transition one molecule from one chiral to another," said Professor Reinhard Dörner of the Institute of Atomic Physics at the Goethe University. His doctoral student, Kilian Fehre, has now brought this dream closer to reality. His observation: the formation of the right or left hand version depends on the direction of the laser illumination initiator.
In his experiments, Kilian Fehre used planar formic acid molecules. He activates it with a strong circularly polarized laser pulse, transforming it into a chiral form. At the same time, radiation breaks down molecules into their atomic components. It is necessary to destroy the molecules in the experiment to determine if a duplicate or mirrored version has been created.
Fehre used the "reaction microscope" (COLTRIMS method) developed by the Institute of Atomic Physics for analysis. It allows the study of individual molecules in a molecular beam. After the molecular explosion breaks down, the data provided by the detector can be used to accurately calculate the direction and speed of the debris path. This makes it possible to reconstruct the spatial structure of the molecule.
In order to produce chiral molecules with the desired chirality in the future, it is necessary to ensure that the molecules are oriented the same in the direction of the circularly polarized laser pulse. This can be achieved by pre-orienting them with a long-wave laser.
This finding may also play a key role in producing a large number of molecules with uniform chirality. However, the researchers believe that in this case, the liquid may radiate rather than gas. "Before we go so far, there is still a lot of work to be done," Kilian Fehre said.
The use of light detection and manipulation of chiral molecules is the focus of priority planning. The program is named after the memorable name "ELCH" and has been funded by the German Research Council since 2018. Scientists from Kassel, Marburg, Hamburg and Frankfurt have joined the program. “Long-term funding and close cooperation with priority programs provide us with the resources necessary to learn to control the chirality of a large number of molecules in the future,” concludes Markus Schöffler, one of the priority project's Frankfurt project managers. .
Important note :