Prof. Dr. Hans-Jürgen Duchstein

Reactive Nitrogen Species [1-3]

Out of the group of nitrovasodilators which are organic nitrates, the most important one in drug therapy, we discuss different metabolizations  (non-enzymatic and enzymatic) in the presence of cytochrome P-450. We use models where  the  active states in the P-450 cycle are imitated with simple metal complexes (porphyrin or salen structures). Further substances that are explored are hydrosylamines, furoxanes, N-nitrosydnonimines and liver-specific nitrovasolidators.

Gentoxicity of Nitrogen Species

We explore active nitrogen species when they act on biological target molecules like partial structures of DNA or RNA. These mechanisms are compared with known reactions of active oxygen species on partical structures of DNA.

Reactive Oxygen Species and Cytochrome P-450 [4,5]

Reactions of singlet oxygen and activated oxygen by cobald complexes show clear similarities. Other important bioelements such as iron and manganese show no activity or only a very low one despite the possibilty of a one-electron transition in this line. We have developed a reaction and activation model for cobald complexes in the presence of oxygen which provides a model for dioxygenase reactions. Monooxygenase reactions play an outstanding role in many metabolic reactions of drugs and contaminants. It has been shown that such biological reactions are imitated in the presence of transition metal complexes. This way, potential metabolites are synthesized to identify possible metabolic pathways and patterns  of new drugs, thus limiting animal testing.

It has also been shown that hydrocarbons cannot be detected in analysis with such biomimetic reagent systems.

Testing Methods for Designer Drugs in Saliva [6]

At present, only a few tests for the routine analysis of illegal drugs are available that may be used in traffic controls. One noninvasive test is based on the use of saliva als body fluid. These tests are developed by us in cooperation with Dräger, Lübeck. In this test, we use test strips employing the ELISA technique.