The Bols group – Københavns Universitet

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Kemisk Institut > Forskning > Kemisk Biologi > The Bols group

The Bols group

The Bols group do synthetic organic chemistry directed at understanding the chemistry of bio-molecules and manipulating them into drugs or chemical machines. Below some more about the research areas you may work in if you join our group. In our group we train students in state of the art organic synthesis, NMR, HPLC, IR and chromatographic techniques. Enzyme or Chemical kinetics will also frequently be part of your project. If you are considering joining us for bachelor or master (speciale) feel free to contact us (bols@chem.ku.dk) to hear more about the specific projects presently available.

G Penicillin is a natural product from fungi

New antibiotics

Bacterial multiresistance to antibiotics is an increasing threat to human health and safety particularly in the hospital environment. Existing antibiotics (penicillin etc), which are natural products or semisynthetic derivatives thereof, are all subject to various clearance mechanisms. There is therefore a demand for new antibiotics with activity towards resistant bacterial strains. In the present project we synthesize potentially new antibiotics using CH-activation reactions. CH-activation is an entirely new family of organo metallic reactions that allow us to convert alkyl groups to alkyl silyl or alkyl boron groups; subsequently the silyl or boron group can be oxidized with H2O2  to hydroxyl or converted to other functional groups. This leads to new derivatives that are tested for antibiotic effect.




 

Artificial enzymes

Enzyme catalysis of chemical reactions occurs with impressive selectivity and rate.

An artificial enzyme that cleaves an acetal, see ref. 1

In the active site the binding of a substrate close to functional groups by proximity effects causes the amazing catalysis. Theoretically it is possible to create similarly powerful catalysts from small molecule mimics of enzyme active sites; a frontier in chemical research is therefore the design and synthesis of small organic molecules (artificial enzymes1), which recreate the active site of an enzyme. This makes it possible to create enzymes that can catalyze new reactions. In the present project we wish to prepare an artificial enzyme that stereoselectively can synthesize a drug molecule. Azaflavonones such as 1 have anticancer activity by being micro-RNA inhibitors2. Azaflavonone 1 has a chiral center and our enzyme must make it stereoselectively. Thanks to enzymes ability to pick out and selectively transform specific molecules biosynthesis greatly surpass modern chemical synthesis in the ability to make complex molecules. While enzymes are protein macromolecules the catalysis is performed in a small part of the enzyme, the active site.




 

Deuterium labeling of drug molecules 

Drug abuse is an increasing problem in the developed countries and the continuous flow of new drugs demands new methods for analysis and quantification. Khat has been used as a stimulant by native Africans for centuries. The abuse has spread world-wide with immigration, and is an increasing problem in Denmark.

Analysis and quantification of the chemical compounds found in khat is the major obstacle for reveal of drug abuse and it is therefore crucial to improve these methods.

In this project, which is a collaboration with the forensic department, we will focus on the synthesis of deuterium labeled compounds, which are use as internal references in analysis and quantification of illegal substances in blood samples or other body liquids. By changing the hydrogens to deuterium the mass is changed, but the behavior in purification remains the same. When having a fixed amount of the deuterated compound it is possible to quantify the drug in the sample. The synthesis of the labeled reference compounds will be explored using cathinone and cathin (figure 6), the active and illegal compounds found in kath. Metal catalysts to affect the exchange of hydrogen with deuterium, via C-H activation, will be studied along with other chemical modifications. The advantage of using C-H activation over other chemical transformations is the direct transformation of the “native” compound into the deuterated derivative, without a lengthy synthesis.




 
With a reliable and general method in hand this will be an important tool for expedite synthesis of labeled compounds and hence very desirable for the forensic chemists, who today are limited by the commercial availability of the compounds.


1 Tetrahedron Letters 2012, 53, 5023–5026.
2 Bioorg. Med. Chem. Lett. 2012, 22, 645–648.