Itoh Group Literature Review

Bradley J. Landgraf † and Squire J. Booker * † ‡ § † Department of Chemistry, ‡ Department of Biochemistry and Molecular Biology, and § The Howard Hughes Medical Institute, The Pennsylvania State University , University Park, Pennsylvania 16802, United States J. Am. Chem. Soc. , Article ASAP DOI: 10.1021/jacs.5b11035 http://pubs.acs.org/doi/abs/10.1021/jacs.5b11035 http://pubs.acs.org/doi/pdf/10.1021/jacs.5b11035 Abstract RimO is a member of the growing radical S-adenosylmethionine (SAM) superfamily of enzymes, which use a reduced [4Fe–4S] cluster to effect reductive cleavage of the 5′ C–S bond of SAM to form a 5′-deoxyadenosyl 5′-radical (5′-dA • ) intermediate. RimO uses this potent oxidant to catalyze the attachment of a methylthio group (−SCH 3 ) to C3 of aspartate 89 of protein S12, one of 21 proteins that compose the 30S subunit of the bacterial ribosome. However, the exact mechanism by which this transformation takes place has remained elusive. H...

Guillaume Passard , Andrew M. Ullman , Casey N. Brodsky , and Daniel G. Nocera * Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States J. Am. Chem. Soc. , Article ASAP DOI: 10.1021/jacs.5b12828 http://pubs.acs.org/doi/abs/10.1021/jacs.5b12828 http://pubs.acs.org/doi/pdf/10.1021/jacs.5b12828 Abstract The selective four electron, four proton, electrochemical reduction of O 2 to H 2 O in the presence of a strong acid (TFA) is catalyzed at a dicobalt center. The faradaic efficiency of the oxygen reduction reaction (ORR) is furnished from a systematic electrochemical study by using rotating ring disk electrode (RRDE) methods over a wide potential range. We derive a thermodynamic cycle that gives access to the standard potential of O 2 reduction to H 2 O in organic solvents, taking into account the presence of an exogenous proton donor. The difference in ORR selectivity for H 2 O...

Antoine Maurin and Marc Robert Laboratoire d’Electrochimie Moléculaire, Univerity of Paris Diderot, Sorbonne Paris Cité, UMR 7591 CNRS , 15 rue Jean- Antoine de Baïf, F-75205 Paris Cedex 13, France J. Am. Chem. Soc. , Article ASAP DOI: 10.1021/jacs.5b12652 http://pubs.acs.org/doi/abs/10.1021/jacs.5b12652 http://pubs.acs.org/doi/pdf/10.1021/jacs.5b12652 Abstract Catalysis of fuel-producing reactions can be transferred from homogeneous solution to surface via attachment of the molecular catalyst. A pyrene-appended iron triphenyl porphyrin bearing six pendant OH groups on the phenyl rings in all ortho and ortho′ positions was immobilized on carbon nanotubes via noncovalent interactions and further deposited on glassy carbon. X-ray photoelectron spectroscopy and electrochemistry confirm catalyst immobilization. Using the carbon material, highly selective and rapid catalysis of the reduction of CO 2 into CO occurs in water (pH 7.3) with 480 mV overpote...

Nicole J. Rijs * † , Patricio González-Navarrete ‡ , Maria Schlangen ‡ , and Helmut Schwarz * ‡ ‡ Institut für Chemie, Technische Universität Berlin , Straße des 17. Juni 115, 10623 Berlin, Germany † Institute of Nanotechnology, Karlsruhe Institute of Technology , Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany J. Am. Chem. Soc. , Article ASAP DOI: 10.1021/jacs.5b12972 http://pubs.acs.org/doi/abs/10.1021/jacs.5b12972 http://pubs.acs.org/doi/pdf/10.1021/jacs.5b12972 Abstract Traveling wave ion mobility spectrometry (TWIMS) isomer separation was exploited to react the particularly well-defined ionic species [LCuO] + (L = 1,10-phenanthroline) with the neutral fluoromethane substrates CH (4– n ) F n ( n = 1–3) in the gas phase. Experimentally, the monofluoromethane substrate ( n = 1) undergoes both hydrogen-atom transfer, forming the copper hydroxide complex [LCuOH] •+ and concomitantly a CH 2 F • radical, and oxygen-atom tran...

Matthew A. DeNardo , Matthew R. Mills , Alexander D. Ryabov * , and Terrence J. Collins * Department of Chemistry, Institute of Green Science, Mellon Institute, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States J. Am. Chem. Soc. , Article ASAP DOI: 10.1021/jacs.5b13087 http://pubs.acs.org/doi/abs/10.1021/jacs.5b13087 http://pubs.acs.org/doi/pdf/10.1021/jacs.5b13087 The main features of iron-tetra-amido macrocyclic ligand complex (a sub-branch of TAML) catalysis of peroxide oxidations are rationalized by a two-step mechanism: Fe III + H 2 O 2 → Active catalyst (Ac) ( k I ), and Ac + Substrate (S) → Fe III + Product ( k II ). TAML activators also undergo inactivation under catalytic conditions: Ac → Inactive catalyst ( k i ). The recently developed relationship, ln( S 0 / S ∞ ) = ( k II / k i )[Fe III ] tot , where S 0 and S ∞ are [S] at time t = 0 and ∞, respectively, gives access to k i under any conditions. Analysis of the rate const...

Mayank Puri, Achintesh N. Biswas, Ruixi Fan, Yisong Guo and Lawrence Que  /  † Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota , Minneapolis, Minnesota 55455, United States ‡ Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States Journal of the American Chemical Society DOI: 10.1021/jacs.5b11511 Visit Website http://pubs.acs.org/doi/pdf/10.1021/jacs.5b11511 ABSTRACT: The non-heme iron halogenases CytC3 and SyrB2 catalyze C − H bond halogenation in the biosyn- thesis of some natural products via S = 2 oxoiron(IV) − halide intermediates. These oxidants abstract a hydrogen atom from a substrate C − H bond to generate an alkyl radical that reacts with the bound halide to form a C − X bond chemoselectively. The origin of this selectivity has been explored in biological systems but has not yet been investigated with synthetic models. Here we repo...

Hideki Sugimoto * † ,  Masanori Sato † ,  Kaori Asano ‡ ,  Takeyuki Suzuki ‡ ,  Kaoru Mieda § ,  Takashi Ogura § ,  Takashi Matsumoto ⊥ ,  Logan J. Giles ∥ ,  Amrit Pokhrel ∥ ,  Martin L. Kirk * ∥ , and  Shinobu Itoh * † †  Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering,  Osaka University , 2-1 Yamadaoka, Suita, Osaka 565-0871,  Japan ‡  Comprehensive Analysis Center, The Institute of Scientific and Industrial Research (ISIR),  Osaka University , 8-1 Mihogaoka, Ibaraki, Osaka 567-0057,  Japan §  Picobiology Institute, Graduate School of Life Science,  University of Hyogo, RSC-UH Leading Program Center , 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 678-0057,  Japan ⊥   Rigaku Corporation , Akishima, Tokyo 196-8666,  Japan ∥  Department of Chemistry and Chemical Biology,  The University of New Mexi...

Yingxia Hu 1 , Yang Wang 2 , Junpeng Deng 1* † and Haobo Jiang 2* † 1Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA 2Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA BMC Biology(2016)14:2 Received: 24 July 2015 Accepted: 23 December 2015 DOI 10.1186/s12915-015-0225-2 http://bmcbiol.biomedcentral.com/articles/10.1186/s12915-015-0225-2 Background Phenoloxidase (PO)-catalyzed melanization is a universal defense mechanism of insects against pathogenic and parasitic infections. In mosquitos such as Anopheles gambiae, melanotic encapsulation is a resistance mechanism against certain parasites that cause malaria and filariasis. PO is initially synthesized by hemocytes and released into hemolymph as inactive prophenoloxidase (PPO), which is activated by a serine protease cascade upon recognition of foreign invaders. The mechanisms of PPO activation and PO catalysis have been ...

Communication Quercetin 2,4-Dioxygenase Activates Dioxygen in a Side-On O 2 –Ni Complex Authors Dr. Jae-Hun Jeoung, Dr. Dimitrios Nianios, Prof. Dr. Susanne Fetzner, Prof. Dr. Holger Dobbek Humboldt-University, Berlin   First published:  5 February 2016 Full publication history DOI:  10.1002/anie.201510741 View/save citation Cited by:  0  articles  Check for new citations Funding Information http://onlinelibrary.wiley.com/doi/10.1002/anie.201510741/epdf Abstract Quercetin 2,4-dioxygenase (quercetinase) from  Streptomyces  uses nickel as the active-site cofactor to catalyze oxidative cleavage of the flavonol quercetin. How this unusual active-site metal supports catalysis and O 2  activation is under debate. We present crystal structures of Ni-quercetinase in three different states, thus providing direct insight into how quercetin and O 2  are activa...

Zhi Shan,ab   Mingsheng Lu,ac   Li Wang,ad   Bruce MacDonald,a   Judy MacInnis,e   Martin Mkandawire,a   Xu Zhang*a and   Ken D. Oakes,af  Verschuren Centre for Sustainability in Energy & the Environment, Cape Breton University, Sydney, Canada  Chem. Commun., 2016,52, 2087-2090 DOI: 10.1039/C5CC07446K url: http://pubs.rsc.org/en/content/articlelanding/2016/cc/c5cc07446k#!divAbstract A highly selective, ultrasensitive (visual and instrumental detection limits of 40 nM and 0.1 nM, respectively), environmentally-friendly, simple and rapid colorimetric sensor was developed for the detection of copper(II) in water. This sensor is based on a novel signal-amplification mechanism involving reactive halide species (RHSs) including chlorides or bromides, which accelerate copper Fenton reactions oxidizing the chromogenic substrate to develop colour. The results of this study expand our understanding of copper-based Fenton chemistry. ...