@misc{KinnePorajKobielskaUllrichetal., author = {Kinne, Matthias and Poraj-Kobielska, Marzena and Ullrich, Ren{\´e} and Nousiainen, Paula and Sipil{\"a}, Jussi and Scheibner, Katrin and Hammel, Kenneth E. and Hofrichter, Martin}, title = {Oxidative cleavage of non-phenolic b-O-4 lignin model dimers by an extracellular aromatic peroxygenase}, series = {Holzforschung}, volume = {65}, journal = {Holzforschung}, number = {5}, issn = {1437-434X}, doi = {10.1515/HF.2011.057}, pages = {673 -- 679}, abstract = {The extracellular aromatic peroxygenase of the agaric fungus Agrocybe aegerita catalyzed the H2O2-dependent cleavage of non-phenolic arylglycerol-b-aryl ethers (b-O-4 ethers). For instance 1-(3,4-dimethoxyphenyl)-2-(2-methoxy-phenoxy)pro- pane-1,3-diol, a recalcitrant dimeric lignin model compound that represents the major non-phenolic substructure in lignin, was selectively O-demethylated at the para-methoxy group to give formaldehyde and 1-(4-hydroxy-3-methoxyphenyl)- 2-(2-methoxyphenoxy)propane-1,3-diol. The phenol moiety of the latter compound was then enzymatically oxidized into phenoxy radicals and a quinoid cation, which initiated the autocatalytic cleavage of the dimer and the formation of monomers such as 2-methoxy-1,4-benzoquinone and phenoxyl-substituted propionic acid. The introduction of 18O from H218O2 and H218O at different positions into the products provided information about the routes of ether cleavage. Studies with a 14C-labeled lignin model dimer showed that more than 70\% of the intermediates formed were further coupled to form polymers with molecular masses above 10 kDa. The results indicate that fungal aromatic peroxyge- nases may be involved in the bioconversion of methoxylated plant ingredients originating from lignin or other sources.}, language = {en} } @misc{PorajKobielskaKinneUllrichetal., author = {Poraj-Kobielska, Marzena and Kinne, Matthias and Ullrich, Ren{\´e} and Scheibner, Katrin and Kayser, Gernot and Hammel, Kenneth E. and Hofrichter, Martin}, title = {Preparation of human drug metabolites using fungal peroxygenases}, series = {Biochemical Pharmacology}, volume = {82}, journal = {Biochemical Pharmacology}, number = {7}, issn = {1873-2968}, doi = {10.1016/j.bcp.2011.06.020}, pages = {789 -- 796}, abstract = {The synthesis of hydroxylated and O- or N-dealkylated human drug metabolites (HDMs) via selective monooxygenation remains a challenging task for synthetic organic chemists. Here we report that aromatic peroxygenases (APOs; EC 1.11.2.1) secreted by the agaric fungi Agrocybe aegerita and Coprinellus radians catalyzed the H₂O₂-dependent selective monooxygenation of diverse drugs, including acetanilide, dextrorphan, ibuprofen, naproxen, phenacetin, sildenafil and tolbutamide. Reactions included the hydroxylation of aromatic rings and aliphatic side chains, as well as O- and N-dealkylations and exhibited different regioselectivities depending on the particular APO used. At best, desired HDMs were obtained in yields greater than 80\% and with isomeric purities up to 99\%. Oxidations of tolbutamide, acetanilide and carbamazepine in the presence of H₂¹⁸O₂ resulted in almost complete incorporation of ¹⁸O into the corresponding products, thus establishing that these reactions are peroxygenations. The deethylation of phenacetin-d₁ showed an observed intramolecular deuterium isotope effect [(k(H)/k(D))(obs)] of 3.1±0.2, which is consistent with the existence of a cytochrome P450-like intermediate in the reaction cycle of APOs. Our results indicate that fungal peroxygenases may be useful biocatalytic tools to prepare pharmacologically relevant drug metabolites.}, language = {en} } @misc{PengWollenbergerKinneetal., author = {Peng, Lei and Wollenberger, Ulla and Kinne, Matthias and Hofrichter, Martin and Ullrich, Ren{\´e} and Scheibner, Katrin and Fischer, Anna and Scheller, Frieder W.}, title = {Peroxygenase based sensor for aromatic compounds}, series = {Biosensors and Bioelectronics}, volume = {26}, journal = {Biosensors and Bioelectronics}, number = {4}, issn = {1873-4235}, doi = {10.1016/j.bios.2010.07.075}, url = {http://nbn-resolving.de/http://www.sciencedirect.com/science/article/pii/S0956566310004501}, pages = {1432 -- 1436}, abstract = {We report on the redox behaviour of the peroxygenase from Agrocybe aegerita (AaeAPO) which has been electrostatically immobilized in a matrix of chitosan-embedded gold nanoparticles on the surface of a glassy carbon electrode. AaeAPO contains a covalently bound heme-thiolate as the redox active group that exchanges directly electrons with the electrode via the gold nanoparticles. The formal potential E ° ′ of AaeAPO in the gold nanoparticles-chitosan film was estimated to be -(286 ± 9) mV at pH 7.0. The heterogeneous electron transfer rate constant (ks) increases from 3.7 in the scan rate range from 0.2 to 3.0 V s-1 and level off at 63.7 s-1. Furthermore, the peroxide-dependent hydroxylation of aromatic compounds was applied to develop a sensor for naphthalene and nitrophenol. The amperometric measurements of naphthalene are based on the indication of H2O2 consumption. For the chitosan-embedded gold nanoparticle system, the linear range extends from 4 to 40 μM naphthalene with a detection limit of 4.0 μM (S/N = 3) and repeatability of 5.7\% for 40 μM naphthalene.}, language = {en} } @misc{KinnePorajKobielskaArandaetal., author = {Kinne, Matthias and Poraj-Kobielska, Marzena and Aranda, Elisabet and Ullrich, Ren{\´e} and Hammel, Kenneth E. and Scheibner, Katrin and Hofrichter, Martin}, title = {Regioselective preparation of 5-hydroxypropranolol and 4′-hydroxydiclofenac with a fungal peroxygenase}, series = {Bioorganic \& Medicinal Chemistry Letters}, volume = {19}, journal = {Bioorganic \& Medicinal Chemistry Letters}, number = {11}, issn = {1464-3405}, doi = {10.1016/j.bmcl.2009.04.015}, pages = {3085 -- 3087}, abstract = {An extracellular peroxygenase of Agrocybe aegerita catalyzed the H2O2-dependent hydroxylation of the multi-function beta-adrenergic blocker propranolol (1-naphthalen-1-yloxy-3-(propan-2-ylamino)propan-2-ol) and the non-steroidal anti-inflammatory drug diclofenac (2-[2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid) to give the human drug metabolites 5-hydroxypropranolol (5-OHP) and 4′-hydroxydiclofenac (4′-OHD). The reactions proceeded regioselectively with high isomeric purity and gave the desired 5-OHP and 4′-OHD in yields up to 20\% and 65\%, respectively. 18O-labeling experiments showed that the phenolic hydroxyl groups in 5-OHP and 4′-OHD originated from H2O2, which establishes that the reaction is mechanistically a peroxygenation. Our results raise the possibility that fungal peroxygenases may be useful for versatile, cost-effective, and scalable syntheses of drug metabolites.}, language = {en} } @misc{KinneUllrichHammeletal., author = {Kinne, Matthias and Ullrich, Ren{\´e} and Hammel, Kenneth E. and Scheibner, Katrin and Hofrichter, Martin}, title = {Regioselective preparation of (R)-2-(4-Hydroxyphenoxy)propionic acid with a fungal peroxygenase}, series = {Tetrahedron Letters}, volume = {49}, journal = {Tetrahedron Letters}, number = {41}, issn = {1873-3581}, doi = {10.1016/j.tetlet.2008.07.152}, pages = {5950 -- 5953}, abstract = {The extracellular heme-thiolate peroxygenase of Agrocybe aegerita catalyzed the H2O2-dependent hydroxylation of 2-phenoxypropionic acid (POPA) to give the herbicide precursor 2-(4-hydroxyphenoxy)propionic acid (HPOPA). The reaction proceeded regioselectively with an isomeric purity near 98\%, and yielded the desired R-isomer of HPOPA with an enantiomeric excess of 60\%. 18O-labeling experiments showed that the phenolic hydroxyl in HPOPA originated from H2O2, which establishes that the reaction is mechanistically a peroxygenation. Our results raise the possibility that fungal peroxygenases may be useful for a variety of organic oxidations.}, language = {en} } @misc{PorajKobielskaKinneUllrichetal., author = {Poraj-Kobielska, Marzena and Kinne, Matthias and Ullrich, Ren{\´e} and Scheibner, Katrin and Hofrichter, Martin}, title = {A spectrophotometric assay for the detection of fungal peroxygenases}, series = {Analytical Biochemistry}, volume = {421}, journal = {Analytical Biochemistry}, number = {1}, doi = {10.1016/j.ab.2011.10.009}, pages = {327 -- 329}, abstract = {Rapid and simple spectrophotometric methods are required for the unambiguous detection of recently discovered fungal peroxygenases in vivo and in vitro. This paper describes a peroxygenase-specific assay using 5-nitro-1,3-benzodioxole as substrate. The product, 4-nitrocatechol, produces a yellow color at pH 7, which can be followed over time at 425 nm (ε425 = 9,700 M-1 cm-1), and a red color when adjusted to pH >12, which can be measured in form of an end-point determination at 514 nm (ε514 = 11,400 M-1 cm-1). The assay is suitable for detecting peroxygenase activities in complex growth media and environmental samples as well as for high-throughput screenings.}, language = {en} }