- A LecA ligand identified from a galactoside-conjugate array inhibits host cell invasion by pseudomonas aeruginosa
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Lectin LecA is a virulence factor of Pseudomonas aeruginosa involved in lung injury, mortality, and cellular invasion. Ligands competing with human glycoconjugates for LecA binding are thus promising candidates to counteract P. aeruginosa infections. We have identified a novel divalent ligand from a focused galactoside(Gal)-conjugate array which binds to LecA with very high affinity (Kd=82 nM). Crystal structures of LecA complexed with the ligand together with modeling studies confirmed its ability to chelate two binding sites of LecA. The ligand lowers cellular invasiveness of P. aeruginosa up to 90% when applied in the range of 0.05-5 μM. Hence, this ligand might lead to the development of drugs against P. aeruginosa infection.
- Novoa, Alexandre,Eierhoff, Thorsten,Topin, Jeremie,Varrot, Annabelle,Barluenga, Sofia,Imberty, Anne,Roemer, Winfried,Winssinger, Nicolas
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Read Online
- Novel nicotinoid structures for covalent modification of wood: An environmentally friendly way for its protection against insects
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Timber is constantly exposed to environmental influences under outdoor conditions which limits its lifetime and usability. In order to counteract the damaging processes caused by insects, we have developed a novel and more environmentally friendly method to protect wood materials via covalent modification by organic insecticides. Starting with an important class of synthetic insecticides which are derived from the natural insecticide nicotine, various new carboxylic acid derivatives of imidacloprid were made accessible. These activated neonicotinoids were utilized for the chemical modification of wood hydroxy groups. In contrast to conventional wood preservation methods in which biocides are only physically bound to the surface for a limited time, the covalent fixation of the preservative guarantees a permanent effect against wood pests, demonstrated in standardized biological tests. Additionally, the environmental interaction caused by non-bound neonicotinoids is significantly reduced, since both, a smaller application rate is required and leaching of the active ingredient is prevented. By minimizing the pest infestation, the lifetime of the material increases while preserving the natural appearance of the material.
- Acker, Sophie,Kaufmann, Dieter E.,Namyslo, Jan C.,Plarre, Rudy,S?ftje, Martin
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p. 15726 - 15733
(2020/05/13)
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- Electrochemically Catalyzed Newman-Kwart Rearrangement: Mechanism, Structure-Reactivity Relationship, and Parallels to Photoredox Catalysis
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The facilitation of redox-neutral reactions by electrochemical injection of holes and electrons, also known as "electrochemical catalysis", is a little explored approach that has the potential to expand the scope of electrosynthesis immensely. To systematically improve existing protocols and to pave the way toward new developments, a better understanding of the underlying principles is crucial. In this context, we have studied the Newman-Kwart rearrangement of O-arylthiocarbamates to the corresponding S-aryl derivatives, the key step in the synthesis of thiophenols from the corresponding phenols. This transformation is a particularly useful example because the conventional method requires temperatures up to 300 °C, whereas electrochemical catalysis facilitates the reaction at room temperature. A combined experimental-quantum chemical approach revealed several reaction channels and rendered an explanation for the relationship between the structure and reactivity. Furthermore, it is shown how rapid cyclic voltammetry measurements can serve as a tool to predict the feasibility for specific substrates. The study also revealed distinct parallels to photoredox-catalyzed reactions, in which back-electron transfer and chain propagation are competing pathways.
- Roesel, Arend F.,Ugandi, Mihkel,Huyen, Nguyen Thi Thu,Májek, Michal,Broese, Timo,Roemelt, Michael,Francke, Robert
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p. 8029 - 8044
(2020/07/25)
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- Synthesis and cytotoxicity studies of novel NHC?-gold(I) complexes derived from lepidiline A
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Ten novel N-heterocyclic carbene gold(I) complexes derived from lepidiline A (1,3-dibenzyl-4,5-dimethylimidazolium chloride) are reported here with full characterisation and biological testing. (1,3-Dibenzyl-4,5-diphenylimidazol-2-ylidene)gold(I) chloride (NHC?-AuCl) (1) was modified by substituting the chloride for the following: cyanide (2), dithiocarbamates (3-5), p-mercaptobenzoate derivatives (12-14) and N-acetyl-L-cysteine derivatives (15-17). All complexes were synthesised in good yields of 57-78%. Complexes 2, 12, 13, and 14 were further characterised by X-ray crystallography. Initial evaluation of the biological activity was conducted on all ten complexes against the multidrug resistant MCF-7topo breast cancer, HCT-116wt, and p53 knockout mutant HCT-116-/- colon carcinoma cell lines. Across the three cell lines tested, mainly single-digit micromolar IC50 values were observed. Nanomolar activity was exhibited on the MCF-7topo cell line with 3 displaying an IC50 of 0.28 μM ± 0.03 μM. Complexes incorporating a Au-S bond resulted in higher cytotoxic activity when compared to complexes 1 and 2. Theoretical calculations, carried out at the MN15/6-311++G(2df,p) computational level, show that NHC? is the more favourable ligand for Au(I)-Cl when compared to PPh3.
- Curran, Danielle,Dada, Oyinlola,Müller-Bunz, Helge,Rothemund, Matthias,Sánchez-Sanz, Goar,Schobert, Rainer,Zhu, Xiangming,Tacke, Matthias
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- Lithium-Catalyzed Thiol Alkylation with Tertiary and Secondary Alcohols: Synthesis of 3-Sulfanyl-Oxetanes as Bioisosteres
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3-Sulfanyl-oxetanes are presented as promising novel bioisosteric replacements for thioesters or benzyl sulfides. From oxetan-3-ols, a mild and inexpensive Li catalyst enables chemoselective C?OH activation and thiol alkylation. Oxetane sulfides are formed from various thiols providing novel motifs in new chemical space and specifically as bioisosteres for thioesters due to their similar shape and electronic properties. Under the same conditions, various π-activated secondary and tertiary alcohols are also successful. Derivatization of the oxetane sulfide linker provides further novel oxetane classes and building blocks. Comparisons of key physicochemical properties of the oxetane compounds to selected carbonyl and methylene analogues indicate that these motifs are suitable for incorporation into drug discovery efforts.
- Croft, Rosemary A.,Mousseau, James J.,Choi, Chulho,Bull, James A.
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supporting information
p. 818 - 821
(2017/12/26)
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- Expanding the SAR of Nontoxic Antiplasmodial Indolyl-3-ethanone Ethers and Thioethers
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Despite major strides in reducing Plasmodium falciparum infections, this parasite still accounts for roughly half a million annual deaths. This problem is compounded by the decreased efficacy of artemisinin combination therapies. Therefore, the development and optimisation of novel antimalarial chemotypes is critical. In this study, we describe our strategic approach to optimise a class of previously reported antimalarials, resulting in the discovery of 1-(5-chloro-1H-indol-3-yl)-2-[(4-cyanophenyl)thio]ethanone (13) and 1-(5-chloro-1H-indol-3-yl)-2-[(4-nitrophenyl)thio]ethanone (14), whose activity was equipotent to that of chloroquine against the P. falciparum 3D7 strain. Furthermore, these compounds were found to be nontoxic to HeLa cells as well as being non-haemolytic to uninfected red blood cells. Intriguingly, several of our most promising compounds were found to be less active against the isogenic NF54 strain, highlighting possible issues with long-term dependability of malarial strains. Finally compound 14 displayed similar activity against both the NF54 and K1 strains, suggesting that it inhibits a pathway that is uncompromised by K1 resistance.
- Lunga, Mayibongwe J.,Chisango, Ruramai L.,Weyers, Carli,Isaacs, Michelle,Taylor, Dale,Edkins, Adrienne L.,Khanye, Setshaba D.,Hoppe, Heinrich C.,Veale, Clinton G. L.
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p. 1353 - 1362
(2018/07/13)
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- Radical Difluoromethylation of Thiols with (Difluoromethyl)triphenylphosphonium Bromide
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A method for facile difluoromethylation of various thiols using (difluoromethyl)triphenylphosphonium bromide under mild reaction conditions is presented. The transformation proceeds in the absence of any transition metal using a bench-stable and readily accessible phosphonium salt. Deuterium labeling experiments and cyclic voltammetry measurements reveal that the difluoromethylation occurs via a SRN1-type mechanism. Substrate scope is broad, and various functional groups are tolerated (OH, NH2, amide, ester).
- Heine, Niklas B.,Studer, Armido
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supporting information
p. 4150 - 4153
(2017/08/14)
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- Heterocyclic compounds useful for kinase inhibition
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Provided herein are compounds useful for kinase inhibition.
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Page/Page column 100
(2016/04/02)
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- COMPOUNDS AND METHODS FOR IDENTIFYING AND/OR QUANTIFYING CARBONYLATED BIOMOLECULES
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The subject invention provides compounds and methods for derivatizing, identifying and/or quantifying carbonylated bio molecules by using compounds of the invention. The invention provides compounds and a method of using such compounds for the analysis of
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Page/Page column 16
(2012/12/13)
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- Novel photoreaction using diphenyl disulfide derivatives: Photoinduced oxidation of allyl alcohol
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Allyl alcohols are oxidized to acrylaldehydes using diphenyl disulfide derivatives upon photoirradiation. The reaction occurs via α-hydrogen abstraction by a sulfanyl radical. Interestingly, the oxidation reaction occurs in moderate yield when a dendrimer disulfide is used as a mediator.
- Tsuboi, Takaaki,Takaguchi, Yutaka,Tsuboi, Sadao
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experimental part
p. 361 - 368
(2009/04/07)
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- 1,3-Dipolar cycloadditions of acetylenic sulfones in solution and on solid supports
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(Chemical Equation Presented) Several representative acetylenic sulfones were immobilized on a polymer support derived from Merrifield resin by means of ester linkers that were used to couple free carboxylic acid groups on the solid support with benzylic hydroxyl functions on the arylsulfonyl moieties of the acetylenes. Several examples of reversed ester linkers, using Merrifield resin directly, were also successfully prepared. The 1,3-dipolar cycloadditions of the solid-supported acetylenic sulfones were investigated with a series of 1,3-dipoles, including benzyl azide, ethyl diazoacetate, diazomethane, as well as representative nitrile oxides, nitrile imines, nitrile ylides, nitrones, azomethine imines, azomethine ylides, munchnones, and sydnones. In general, analogous cycloadditions were also performed with acetylenic sulfones in solution phase for comparison. The cycloadditions typically afforded good to excellent yields of the desired products in both solution and solid phase, although the latter reactions sometimes required more vigorous conditions. Except in the case of benzyl azide and diazo compounds, where mixtures of regioisomers were obtained, the other 1,3-dipoles reacted with high regioselectivity and afforded essentially unique regioisomers. Cleavage of the products from the resin was smoothly effected by alkaline hydrolysis, while several attempts at reductive desulfonylation with sodium amalgam or samarium diiodide-HMPA resulted in N-O or C-O scission, in addition to cleavage from the polymer. The method provides access to a number of important classes of heterocycles, including variously substituted and functionalized triazoles, pyrazoles, 1,2-oxazoles, pyrroles, as well as their dihydro and bicyclic analogues. The success of the cycloadditions on polymer supports paves the way to future investigations of sequential transformations leading to libraries of useful heterocycles.
- Gao, Detian,Zhai, Huimin,Parvez, Masood,Back, Thomas G.
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p. 8057 - 8068
(2008/12/22)
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- THERAPEUTIC AGENT FOR RESPIRATORY DISEASE CONTAINING 4-HYDROXYPIPERIDINE DERIVATIVE AS ACTIVE INGREDIENT
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An agent for preventing/treating respiratory diseases contains, as an active ingredient, a compound represented by following Formula (I): wherein A is a group represented by L-W [wherein L is a bond or CH2; and W is O, SOn (wherein n is 0 to 2), or -NR7-(wherein R7 is hydrogen or lower alkyl)]; each of G1 and G2 is (CH2)r (wherein r is 0 to 2), provided that when n is 1, G1 and G2 may be bridged by lower alkylene; Y is a lower alkylene or (substituted) benzylidene; Z is a bond or O, provided that when Z is a bond, Y may form a 5- or 6-membered ring with carbon on the benzene ring; R1 is, for example, NO2, a lower alkoxycarbonyl, (substituted) carbamoyl, (protected) hydroxyl group, (protected) carboxyl, or (protected) N-hydroxycarbamoyl; each of R2and R3 is hydrogen, halogen, (halogenated) lower alkyl, (halogenated) lower alkoxy or NO2; each of R4 and R5 is, for example, hydrogen, halogen, (halogenated) lower alkyl, (halogenated) lower alkoxy, CN, or lower alkylsulfonyl; and R6 is hydrogen or lower alkyl, a salt thereof or a solvate of them. It has excellent antitussive activity when used as an agent for preventing/treating respiratory diseases such as lung cancer, common cold syndrome, pulmonary tuberculosis, pneumonia, acute bronchitis or chronic bronchitis.
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Page/Page column 44
(2008/06/13)
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- Retinoid-like compounds
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The present invention relates to a compound of formula I STR1 or a nontoxic pharmaceutically acceptable salt, physiologically hydrolyzable ester or solvate thereof, in whichX is --O--CO--, --NH--CO--, --CS--NH--, --CO--O--, --CO--NH--, --COS--, --SCO--, --SCH 2 --, --CH 2 --CH 2 --, --C C--, --CH 2 --NH--, --COCH 2 --, --NHCS--, --CH 2 S--, --CH 2 O--, --OCH 2 --, --NHCH 2 -- or --CR 5 CR 6 --;R m and R k are independently hydrogen, halogen, C 1-6 alkyl, hydroxy, C 1-6 alkyloxy or nitro;n is zero or one;R 4 is --(CH 2) t --Y, C 1-6 alkyl, or C 3-6 cycloalkyl;R 1 is --CO 2 Z, C 1-6 alkyl, CH 2 OH, --CONHR y, or CHO;R 2 and R 3 are independently hydrogen or C 1-6 alkyl;R a and R b are independently hydrogen or C 1-6 alkyl; but when n is one, R a and R b together can form a radical of the formula STR2 Y is naphthyl or phenyl, both radicals can be optionally substituted with one to three same or different C 1-6 alkyl or halogen;Z is hydrogen or C 1-6 alkyl;R 5, R 6 and R y are independently hydrogen or C 1-6 alkyl; andt is zero to six.
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- Retinoid-like compounds
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The present invention relates to a compound of formula STR1 or a nontoxic pharmaceutically acceptable salt, physiologically hydrolyzable ester or solvate thereof, in which X is --O--CO--, --NH--CO--, --CS--NH--, --CO--O--, --CO--NH--, --COS--, --SCO--, --SCH2 --, --CH2 --CH2 --, --C C--, --CH2 --NH--, --COCH2 --, --NHCS--, --CH2 S--, --CH2 O--, --OCH2 --, --NHCH2 -- or --CR5 =CR6 --; Rm and Rk are independently hydrogen, halogen, C1-6 alkyl, hydroxy, C1-6 alkyloxy or nitro; n is zero or one; R4 is --(CH2)t --Y, C1-6 alkyl, or C3-6 cycloalkyl; R1 is --CO2 Z, C1-6 alkyl, CH2 OH, --CONHRy, or CHO; R2 and R3 are independently hydrogen or C1-6 alkyl; Ra and Rb are independently hydrogen or C1-6 alkyl; but when n is one, Ra and Rb together can form a radical of the formula STR2 Y is naphthyl or phenyl, both radicals can be optionally substituted with one to three same or different C1-6 alkyl or halogen; Z is hydrogen or C1-6 alkyl; R5, R6 and Ry are independently hydrogen or C1-6 alkyl; and t is zero to six.
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- Two efficient and practical syntheses of methyl 4-mercaptobenzoate
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Two efficient syntheses of methyl-4-mercaptobenzoate are described, one utilizing the dianion of 4-bromothiophenol, the other a S(N)Ar reaction starting with 4-fluorobenzonitrile.
- Tickner,Huang,Gombatz,Mills,Novack,Webb
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p. 2497 - 2505
(2007/10/02)
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- Oxidative Cleavage of S-Arylmercaptoacetic Acids by Sodium Perborate: Kinetic and Correlation Study
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Kinetics of oxidation of twenty six S-arylmercaptoacetic acids (SAMA) (I) by sodium perborate (PB) have been studied in acid medium.The product of oxidation is the corresponding thiophenol.The rate data of meta- and para-substituted acids have been correlated with DSP equations.While the para-compounds correlate well with ?I and ?0R values, the meta-compounds correlate well with ?I and ?-R values.The reaction constants are negative and of smaller magnitudes.Further, the ortho-substituted acids show a good correlation with a triparametric equation involving Taft's ?I and ?0R and Charton's steric parameter ν.There is a considerable steric contribution to the total ortho-substituent effect.Based on these observations, mechanism involving the formation of protonated arylsulfinylacetic acid intermediate, followed by an intramolecular rearrangement leading to the product thiophenol has been proposed.
- Kabilan, S.,Pandiarajan, K.,Krishnasamy, K.,Sankar, P.
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p. 443 - 452
(2007/10/02)
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- Ion-radical perfluoroalkylation. Part 11. Perfluoroalkylation of thiols by perfluoroalkyl iodides in the absence of initiators
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Perfluoroalkylation of aliphatic, aromatic and heterocyclic thiols by perfluoroalkyl iodides in the presence of Et3N appears to occur spontaneously under daylight or the usual laboratory lighting conditions at 20-22 deg C and is complete in 10-15 min to 2-3 h.An exception to this rule are thiols with a low nucleophilicity.The reaction is accompanied by thiol oxidation (2percent-3percent) and depends directly on the temperature, lighting, solvent polarity and electronic properties of the perfluoroalkylating agents and of the thiol substituents.At the same time, formation of diaryl disulphides frequently occurs contrary to above rules.The reaction mechanism is discussed. - Keywords: Ion-radical perfluoroalkylation; Thiols; Perfluoroalkyl iodides; Reaction mechanism; Nucleophilicity; NMR spectroscopy
- Boiko, V. N.,Shchupak, G. M.
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p. 207 - 212
(2007/10/02)
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- Aryl alkenoic acid derivatives as leukotriene antagonists
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Aryl alkenoic acid derivatives, and physiologically acceptable salts thereof, are provided which are potent leukotriene antagonists and may be used for the treatment of circulatory diseases and preferably for respiratory diseases such as asthma. The deriv
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- Diarylstrylquinoline diacids and pharmaceutical compositions thereof
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Compounds having the formula: STR1 are leukotriene antagonists and inhibitors of leukotriene biosynthesis. These compounds are useful as anti-asthmatic, anti-allergic, anti-inflammatory, and cytoprotective agents.
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- Leukotriene antagonists
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Leukotriene antagonists are disclosed comprising compounds having the general formula represented by the formula shown below, esters, amides and physio-logically acceptable salts thereof. These compounds retain the natural 5(S) 6(R) configuration, the 5-hydroxyl group and the natural unsaturated tail with the peptide replaced by a substituted aromatic nucleus linked via a sulfur or oxygen substituent linking a substituent to the 6 position.
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- The Methyl Group as A Protecting Group for Arylthiols: A Mild and Efficient Method for the Conversion of Methyl Aryl Sulfides to Arylthiols
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Methyl aryl sulfides are converted in a mild, "one-pot", three step procedure via Pummerer rearrangement of the corresponding sulfoxides, and without purification of intermediates, to provide arylthiols in excellent yields.
- Young, Robert Norman,Gauthier, Jacques Yves,Coombs, William
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p. 1753 - 1756
(2007/10/02)
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