@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{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} }