Andreas Christopher Kretschmann

Andreas Christopher Kretschmann

Guest researcher


The current research project investigates the enantioselective endocrine disrupting effects of emerging contaminants in humans and the environment. Recent studies report the detection of a large number of xenobiotic chemicals, like pharmaceuticals, pesticides, personal care products, and industrial chemicals, in surface and ground water. The effects and the risk of these compounds, particularly when occurring as a mixture, are largely unknown. Furthermore, several of these emerging contaminants are chiral, i.e., they occur as mixtures of their stereoisomers (enantiomers). Although similar in their physico-chemical properties, enantiomers can differ hugely in their activities towards biological systems and cause different effects, as it is well known for pharmaceuticals. Nevertheless, chirality is a hardly considered aspect in risk assessment of emerging contaminants. The goal of my work is to elucidate the importance of chirality in the effect assessment of particularly pharmaceuticals and pesticides. Hereby, the focus is on enantioselective endocrine disrupting effects in humans, which are analyzed with in vitro and in vivo test systems. For further information please contact:



  • Kretschmann, A., Gottardi, M., Dalhoff, K., Cedergreen, N., The Synergistic Potential of the Azole Fungicides Prochloraz and Propiconazole Towards a Short α-Cypermethrin Pulse Increases Over Time in Daphnia magna. Submitted for publication.
  • Gottardi, M.; Kretschmann, A.; Cedergreen, N., Measuring Cytochrome P450 (ECOD) Activity in Aquatic Invertebrates: A Critical Evaluation of in vitro and in vivo Methods. Submitted for publication.
  • Jeon, J.; Kretschmann, A.; Escher, B. I.; Hollender, J., Characterization of acetylcholinesterase inhibition and energy allocation in Daphnia magna exposed to carbaryl. Ecotoxicol. Environ. Saf. 2013, 98, (0), 28-35.
  • Kretschmann A, Ashauer R, Hollender J, Escher BI. 2012. Toxicokinetic and Toxicodynamic Model for Diazinon Toxicity – Mechanistic Explanation of Differences in the Sensitivity of Daphnia magna and Gammarus pulex. Environmental Toxicology&Chemistry 31:2014-2022.
  • Kretschmann A, Ashauer R, Preuss TG, Spaak P, Escher BI, Hollender J. 2011.  Toxicokinetic model describing bioconcentration and biotransformation of diazinon in Daphnia magna. Environmental Science& Technology 45:4995-5002.
  • Kretschmann A, Ashauer R, Hitzfeld K, Spaak P, Hollender J, Escher BI. 2011. Mechanistic toxicodynamic model for receptor-mediated toxicity of diazoxon, the active metabolite of diazinon, in Daphnia magna. Environmental Science& Technology 45:4980-4987.
  • Ashauer, R.; Agatz, A.; Albert, C.; Ducrot, V.; Galic, N.; Hendriks, J.; Jager, T.; Kretschmann, A.; O'Connor, I.; Rubach, M. N.; Nyman, A.-M.; Schmitt, W.; Stadnicka, J.; van den Brink, P. J.; Preuss, T. G.. 2011. Toxicokinetic-toxicodynamic modeling of quantal and graded sublethal endpoints: A brief discussion of concepts. Environmental Toxicology& Chemistry, 30, (11), 2519-2524.
  • Hieringer, W.; Flechtner, K.; Kretschmann, A.; Seufert, K.; Auwärter, W.; Barth, J. V.; Görling, A.; Steinrück, H.-P.; Gottfried, J. M.. 2011. The Surface Trans Effect: Influence of Axial Ligands on the Surface Chemical Bonds of Adsorbed Metalloporphyrins. Journal of the American Chemical Society, 133, (16), 6206-6222.
  • Ashauer R, Hintermeister A, Caravatti I, Kretschmann A, Escher BI. 2010. Toxicokinetic and toxicodynamic modeling explains carry-over toxicity from exposure to diazinon by slow organism recovery. Environmental Science& Technology 44:3963-3971.
  • *Kretschmann A, Walz MM, Flechtner K, Steinrück HP, Gottfried JM. 2007. Tetraphenylporphyrin picks up zinc atoms from a silver surface. Chemical Communications:568-570.
  • Shubina TE, Marbach H, Flechtner K, Kretschmann A, Jux N, Buchner F, Steinrück HP, Clark T, Gottfried JM. 2007. Principle and mechanism of direct porphyrin metalation: Joint experimental and theoretical investigation. Journal of the American Chemical Society 129:9476-9483.
  • Flechtner K, Kretschmann A, Steinrück HP, Gottfried JM. 2007. NO-induced reversible switching of the electronic interaction between a porphyrin-coordinated cobalt ion and a silver surface. Journal of the American Chemical Society 129:12110-12111.
  • Flechtner K, Kretschmann A, Bradshaw LR, Walz MM, Steinrück HP, Gottfried JM. 2007. Surface-confined two-step synthesis of the complex (ammine)(meso- tetraphenylporphyrinato)-zinc(II) on Ag(111). Journal of Physical Chemistry C 111:5821-5824.
  • Gottfried JM, Flechtner K, Kretschmann A, Lukasczyk T, Steinrück HP. 2006. Direct synthesis of a metalloporphyrin complex on a surface. Journal of the American Chemical Society 128:5644-5645.

ID: 34256493