- Diphenylurea derivatives for combating methicillin- and vancomycin-resistant Staphylococcus aureus
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A new class of diphenylurea was identified as a novel antibacterial scaffold with an antibacterial spectrum that includes highly resistant staphylococcal isolates, namely methicillin- and vancomycin-resistant Staphylococcus aureus (MRSA & VRSA). Starting with a lead compound 3 that carries an aminoguanidine functionality from one side and a n-butyl moiety on the other ring, several analogues were prepared. Considering the pharmacokinetic parameters as a key factor in structural optimization, the structure-activity-relationships (SARs) at the lipophilic side chain were rigorously examined leading to the discovery of the cycloheptyloxyl analogue 21n as a potential drug-candidate. This compound has several notable advantages over vancomycin and linezolid including rapid killing kinetics against MRSA and the ability to target and reduce the burden of MRSA harboring inside immune cells (macrophages). Furthermore, the potent anti-MRSA activity of 21n was confirmed in?vivo using a Caenorhabditis elegans animal model. The present study provides a foundation for further development of diphenylurea compounds as potential therapeutic agents to address the burgeoning challenge of bacterial resistance to antibiotics.
- Eissa, Ibrahim H.,Mohammad, Haroon,Qassem, Omar A.,Younis, Waleed,Abdelghany, Tamer M.,Elshafeey, Ahmed,Abd Rabo Moustafa, Mahmoud M.,Seleem, Mohamed N.,Mayhoub, Abdelrahman S.
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supporting information
p. 73 - 85
(2017/03/02)
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- Method for estimating SN1 rate constants: Solvolytic reactivity of benzoates
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Nucleofugalities of pentafluorobenzoate (PFB) and 2,4,6-trifluorobenzoate (TFB) leaving groups have been derived from the solvolysis rate constants of X,Y-substituted benzhydryl PFBs and TFBs measured in a series of aqueous solvents, by applying the LFER equation: log k = sf(Ef + Nf). The heterolysis rate constants of dianisylmethyl PFB and TFB, and those determined for 10 more dianisylmethyl benzoates in aqueous ethanol, constitute a set of reference benzoates whose experimental ΔG ? have been correlated with the ΔH? (calculated by PCM quantum-chemical method) of the model epoxy ring formation. Because of the excellent correlation (r = 0.997), the method for calculating the nucleofugalities of substituted benzoate LGs have been established, ultimately providing a method for determination of the SN1 reactivity for any benzoate in a given solvent. Using the ΔG? vs ΔH? correlation, and taking sf based on similarity, the nucleofugality parameters for about 70 benzoates have been determined in 90%, 80%, and 70% aqueous ethanol. The calculated intrinsic barriers for substituted benzoate leaving groups show that substrates producing more stabilized LGs proceed over lower intrinsic barriers. Substituents on the phenyl ring affect the solvolysis rate of benzhydryl benzoates by both field and inductive effects.
- Matic, Mirela,Denegri, Bernard,Kronja, Olga
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supporting information
p. 8986 - 8998,13
(2012/12/12)
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- PLANT DISEASE CONTROL AGENT, AND PLANT DISEASE CONTROL METHOD
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Disclosed is a plant disease control agent comprising an amide compound represented by the formula (1) as an active ingredient. (1): wherein X1 represents a fluorine atom or a methoxy group; X2 represents a hydrogen atom, a halogen atom, a C1-C4 alkyl group, a C2-C4 alkenyl group, a C1-C4 haloalkyl group, a C1-C4 alkoxy group, a C1-C4 alkylthio group, a C1-C4 hydroxyalkyl group and so on; Z1 represents an oxygen atom or a sulfur atom; A1 represents a single bond, -CH2- and so on; and G1 represents a group CR6R7R8, a C3-6 cycloalkyl group and so on.
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Page/Page column 48-49
(2010/05/13)
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- Organometallic control over the regiospecificity of functionalization reactions: 1,2,3-Trifluorobenzene and bromo derivatives thereof as substrates
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In a case study, 1,2,3-trifluorobenzene was functionalized at each of the two vacant positions (producing the benzoic acids 1 and 2) and, in addition, bromine was introduced into all available positions (producing the benzoic acids 3-5). The required regioflexibility was achieved by applying novel organometallic recipes such as deprotonation-triggered halogen migrations and site-discriminating competitive halogen-metal permutations. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Heiss, Christophe,Schlosser, Manfred
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p. 447 - 451
(2007/10/03)
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- Fragmentation of radical anions of polyfluorinated benzoates
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A comprehensive study of the symmetry forbidden fragmentation of short-lived radical anions (RAs) has been undertaken for the complete set of polyfluorinated benzoates (C6FnH5-nCO22, n = 1-5). The decay rate constants (kc) of RAs have been determined in aqueous alkaline solution (pH 13.4) by electron photoinjection (EPI) from mercury electrodes and were found to increase dramatically from ≤3 × 103 s-1 (3-F - C6H4CO2-) to (1.2 ± 0.8) × 109 s-1 (C6F5CO2-). The regioselectivity of C-F bond cleavage in the RA fragmentation has been revealed by structure assignment of reduction products of the polyfluorinated benzoic acids by Na, K, and Zn in liquid NH3, as well as by Zn in aqueous NH3 and aqueous alkaline solutions. The kc values depend on the position of the cleaved fluorine to the CO2- group generally in the order para > ortho > meta, and to sharply increase if adjacent fluorine atoms are present. The observed trends reveal that the kinetics of the RA fragmentation reaction is not controlled by the reaction thermodynamics. Semiempirical UHF/INDO calculations, the validity of which has been confirmed by ab initio ROHF/6-31+G calculations, were done to rationalize the observed trends. The reaction transition state (TS) was considered to arise from the RA's and 2*states crossing avoided due to out-of-plane deviation of the cleaving C-F bond. The satisfactory linear correlation (R = 0.96) between the model reaction energy barrier Ea and log kc has been achieved with modeling the local solvation of the CO2- group by its protonation.
- Konovalov, Valery V.,Laev, Sergey S.,Beregovaya, Irina V.,Shchegoleva, Lyudmila N.,Shteingarts, Vitalij D.,Tsvetkov, Yuri D.,Bilkis, Itzhak
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p. 352 - 361
(2007/10/03)
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- Regioselective ortho-hydrodefluorination of pentafluorobenzoic acid by low-valent nickel complexes
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2,3,4,5-Tetrafluorobenzoic and 3,4,5-trifluorobenzoic acids were prepared in high yields by reaction of C6F5COOH with zinc in the presence of NiCl2-2′-bipyridine (or 1,10-phenanthroline) complexes.
- Adonin,Starichenko
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- Elemental fluorine. Part 1. Synthesis of fluoroaromatic compounds
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Direct fluorination of 4-fluorobenzoic acid, as a model substrate in a variety of reaction media, shows that 98% formic acid and concentrated sulfuric acid are excellent for promoting electrophilic fluorination. A high degree of fluorination may be achieved using concentrated sulfuric acid, showing that in this medium fluorine will act as a powerful electrophile.
- Chambers, Richard D.,Skinner, Christopher J.,Hutchinson, John,Thomson, Julie
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p. 605 - 609
(2007/10/03)
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