ISBN: 978-83-60043-10-3 - eurobic9

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P129. Selenium, Tellurium and Transition Metals as Chemical Ingredients
of Intelligent Antioxidants
H. Mohammed a , S. Mecklenburg a , M. Doering a , S. Shaaban a , T. Burkholz a , C. Collins b ,
M. Abbas a , A. Anwar a , C. Jacob Claus a
a Bioorganic Chemistry, University of Saarland, University Campus, 66123, Saarbruecken, Germany,
b School of Biological and Chemical Sciences, University of Exeter, Stocker Road, Exeter, UK
e-mail: h.mohammed@mx.uni-saarland.de
Elements such as selenium and tellurium are generally not too popular in Bioinorganic Chemistry. Nonetheless,
the combination of selenium, tellurium and various transition metal ions in chemically simple molecules
provides a successful recipe for powerful pro- and antioxidants, which may be further ‘spiced' by the addition of
organic redox centres [1, 2]. Antioxidants are used against oxidative stress (OS), a disturbance in redox
homeostasis associated with numerous human diseases. Importantly, OS is not a single molecule event, but is
associated with the increase in intracellular concentrations of various reactive, oxidizing species, and loss of
antioxidant defence. Since reactive oxygen species (ROS), iron and copper ions are among the major culprits
causing and propagating OS, we have considered the design of multifunctional molecules which combine the
ability to remove ROS and bind (and disarm) adventitious metal ions [2]. These molecules are synthesised using
various synthetic techniques, including multicomponent reactions and integrate one or more sulfur, selenium and
tellurium redox centres with macrocycles, phenolic and quinone-based redox sites [3]. They exhibit an exciting
electrochemical behaviour and bind/exchange zinc, copper and iron ions [1]. They are catalytically active and,
when tested in skin cell culture, show strong antioxidant effects, probably due to catalytic destruction of ROS
and exchange of beneficial zinc ions for toxic copper/iron ions.
References:
[1] Mecklenburg, S.; Collins, C. A.; Doring, M.; Burkholz, T.; Abbas, M.; Fry, F. H.; Pourzand, C.; Jacob,
C. Phosphorus Sulfur and Silicon and the Related Elements 2008, 183 (4), 863-88.
[2] Collins, C. A.; Fry, F. H.; Holme, A. L.; Yiakouvaki, A.; Al-Qenaei, A.; Pourzand, C.; Jacob, C. Org.
Biomol. Chem. 2005, 3 (8), 1541-1546.
[3] Shabaan, S.; Abbas, M.; Jacob, C. 2008, Manuscript in preparation.
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