@misc{HerzogHansenMiethbaueretal., author = {Herzog, Natalie and Hansen, Max and Miethbauer, Sebastian and Schmidtke, Kai-Uwe and Anderer, Ursula and Lupp, Amelie and Sperling, Sebastian and Seehofer, Daniel and Damm, Georg and Scheibner, Katrin and K{\"u}pper, Jan-Heiner}, title = {Primary like human hepatocytes genetically engineered to obtain proliferation competence display liver biotransformation activity in 2D and 3D culture systems}, series = {Cell Biology International}, volume = {40}, journal = {Cell Biology International}, number = {3}, issn = {1095-8355}, pages = {341 -- 353}, language = {en} } @misc{SteinbrechtKoenigSchmidtkeetal., author = {Steinbrecht, Susanne and K{\"o}nig, Rosalie and Schmidtke, Kai-Uwe and Herzog, Natalie and Scheibner, Katrin and Kr{\"u}ger-Genge, Anne and Jung, Friedrich and Kammerer, Sarah and K{\"u}pper, Jan-Heiner}, title = {Metabolic activity testing can underestimate acute drug cytotoxicity as revealed by HepG2 cell clones overexpressing cytochrome P450 2C19 and 3A4}, series = {Toxicology}, volume = {412}, journal = {Toxicology}, issn = {0300-483X}, doi = {10.1016/j.tox.2018.11.008}, pages = {37 -- 47}, language = {en} } @misc{SteinbrechtKiebistKoenigetal., author = {Steinbrecht, Susanne and Kiebist, Jan and K{\"o}nig, Rosalie and Thiessen, Markus and Schmidtke, Kai-Uwe and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Scheibner, Katrin}, title = {Synthesis of cyclophosphamide metabolites by a peroxygenase from Marasmius rotula for toxicological studies on human cancer cells}, series = {AMB Express}, volume = {10}, journal = {AMB Express}, issn = {2191-0855}, doi = {10.1186/s13568-020-01064-w}, pages = {13}, abstract = {Cyclophosphamide (CPA) represents a widely used anti-cancer prodrug that is converted by liver cytochrome P450 (CYP) enzymes into the primary metabolite 4-hydroxycyclophosphamide (4-OH-CPA), followed by non-enzymatic generation of the bioactive metabolites phosphoramide mustard and acrolein. The use of human drug metabolites as authentic standards to evaluate their toxicity is essential for drug development. However, the chemical synthesis of 4-OH-CPA is complex and leads to only low yields and undesired side products. In past years, fungal unspecific peroxygenases (UPOs) have raised to powerful biocatalysts. They can exert the identical selective oxyfunctionalization of organic compounds and drugs as known for CYP enzymes with hydrogen peroxide being used as sole cosubstrate. Herein, we report the efficient enzymatic hydroxylation of CPA using the unspecific peroxygenase from Marasmius rotula (MroUPO) in a simple reaction design. Depending on the conditions used the primary liver metabolite 4-OH-CPA, its tautomer aldophosphamide (APA) and the overoxidized product 4-ketocyclophosphamide (4-keto-CPA) could be obtained. Using a kinetically controlled approach 4-OH-CPA was isolated with a yield of 32\% (purity > 97.6\%). Two human cancer cell lines (HepG2 and MCF-7) were treated with purified 4-OH-CPA produced by MroUPO (4-OH-CPAUPO). 4-OH-CPAUPO-induced cytotoxicity as measured by a luminescent cell viability assay and its genotoxicity as measured by γH2AX foci formation was not significantly different to the commercially available standard. The high yield of 4-OH-CPAUPO and its biological activity demonstrate that UPOs can be efficiently used to produce CYP-specific drug metabolites for pharmacological assessment.}, language = {en} } @misc{ScheibnerKuepperSchmidtkeetal., author = {Scheibner, Katrin and K{\"u}pper, Jan-Heiner and Schmidtke, Kai-Uwe and Miethbauer, Sebastian and Herzog, Natalie}, title = {Verfahren zur Herstellung von biogenen Stoffen}, language = {de} } @misc{ScheibnerKiebistSchmidtkeetal., author = {Scheibner, Katrin and Kiebist, Jan and Schmidtke, Kai-Uwe and K{\"u}pper, Jan-Heiner}, title = {Verfahren zur enzymatischen Herstellung von zytostatischen 4-Hydroxy-Oxazaphosphorinen"}, language = {de} } @misc{ScheibnerKuepperJung, author = {Scheibner, Katrin and K{\"u}pper, Jan-Heiner and Jung, Friedrich}, title = {In vitro Arzneimittel aus Prodrugs und deren Verwendung}, language = {de} }