- Ebsulfur as a potent scaffold for inhibition and labelling of New Delhi metallo-β-lactamase-1 in vitro and in vivo
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The superbug infection caused by New Delhi metallo-β-lactamase (NDM-1) has grown into an emerging threat, labelling and inhibition of NDM-1 has proven challenging due to its shuttling between pathogenic bacteria. Here, we report a potent covalent scaffold, ebsulfur, for targeting the protein in vitro and in vivo. Enzymatic kinetic study indicated that eighteen ebsulfurs gained except 1a–b and 1f inhibited NDM-1, exhibiting an IC50 value ranging of 0.16–9 μM, and 1g was found to be the best, dose- and time-dependent inhibitor with an IC50 of 0.16 μM. Also, these ebsulfurs effectively restored the antibacterial activity of cefazolin against E. coli expressing NDM-1, and the best effect was observed to be from 1g, 1i and 1n, resulting in an 256-fold reduction in MIC of the antibiotic at a dose of 16 μg/mL. The equilibrium dialysis study implied that the ebsulfur disrupted the coordination of one Zn(II) ion at active site of NDM-1. Labelling of NDM-1 using a constructed fluorescent ebsulfur Ebs-R suggested that the inhibitor covalently bound to the target through SDS-PAGE analysis in vitro. Also, labelling NDM-1 in living E. coli cells with Ebs-R by confocal microscopic imaging showed the real-time distribution change process of intracellular recombinant protein NDM-1. Moreover, the cytotoxicity of these ebsulfurs against L929 mouse fibroblastic cells was tested, and their capability to restore antibacterial activity of antibiotic against clinical strains E. coli EC08 producing NDM-1 was determined. The ebsulfur scaffold proposed here is valuable for development of the covalent irreversible inhibitors of NDM-1, and also for labelling the target in vitro and in vivo.
- Su, Jianpeng,Liu, Jiayun,Chen, Cheng,Zhang, Yuejuan,Yang, Kewu
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- Development of chiral N-alkylcarbamates as new leads for potent and selective H3-receptor antagonists: Synthesis, capillary electrophoresis, and in vitro and oral in vivo activity
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Novel carbamates as derivatives of 3-(1H-imidazol-4-yl)propanol with an N-alkyl chain were prepared as histamine H3-receptor antagonists. Branching of the N-alkyl side chain with methyl groups led to chiral compounds which were synthesized stereospecifically by a Mitsunobu protocol adapted Gabriel synthesis. The optical purity of some of the chiral compounds was determined (ee > 95%) by capillary electrophoresis (CE). The investigated compounds showed pronounced to high antagonist activity (K(i) values of 4.1-316 nM) in a functional test for histamine H3 receptors on rat cerebral cortex synaptosomes. Similar H3-receptor antagonist activities were observed in a peripheral model on guinea pig ileum. No stereoselective discrimination for the H3 receptor for the chiral antagonists was found with the in vitro assays. All compounds were also screened for central H3-receptor antagonist activity in vivo in mice after po administration. Most compounds were potent agents of the H3-receptor-mediated enhancement of brain N(τ)- methylhistamine levels. The enantiomers of the N-2-heptylcarbamate showed a stereoselective differentiation in their pharmacological effect in vivo (ED50 of 0.39 mg/kg for the (S)-derivative vs 1.5 mg/kg for the (R)- derivative) most probably caused by differences in pharmacokinetic parameters. H1- and H2-receptor activities were determined for some of the novel carbamates, demonstrating that they have a highly selective action at the histamine H3 receptor.
- Sasse, Astrid,Kiec-Kononowicz, Katarzyna,Stark, Holger,Motyl, Malgorzata,Reidemeister, Sibylle,Ganellin, C. Robin,Ligneau, Xavier,Schwartz, Jean-Charles,Schunack, Walter
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- Synthesis of new coumarin compounds and its hypoglycemic activity and structure-activity relationship
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Novel coumarin compounds were designed and synthesized by combining the active moieties of hypoglycemic drugs. The coumarin compounds were made by sulfanilamide with isocynate, the intermediate sulfanilamide was formed from coumarin by chlorosulfonated and aminated. These targeted compounds were characterized by FT-IR, 1H NMR and MS spectra and their hypoglycemic activities were evaluated in mice. The preliminary results showed that some compounds exhibited evident hypoglycemic effect (P > 0.01, CMC-Na as negative control). The relationship between these compounds structure with their hypoglycemic activities were studied in order to design new antidiabetic agents.
- Qi, Gang,Zhang, Wenguo
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p. 9835 - 9839
(2014/01/06)
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- Organosilicon synthesis of isocyanates: II. Synthesis of aliphatic, carbocyclic, and fatty-aromatic isocyanates
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Silylation of a series of aliphatic, carbocyclic, and fatty-aromatic amines gave the corresponding silyl derivatives whose yield depended on the electronic and steric structure of the substrate and the nature of the silylating agent. The yield of isocyanates obtained by phosgenation of the silyl derivatives under mild conditions decreased in going from aliphatic amines to benzylamines and rose as the length of the alkyl chain in fatty-aromatic amines extended. The most convenient procedure for the synthesis of low-boiling alkyl isocyanates was found to be based on the transformation of amines or ammonium salts into silyl or silyl silyl-carabamates, followed by pyrolysis of the latter in the presence of trichloro(phenyl)silane. Pleiades Publishing, Inc., 2006.
- Lebedev,Lebedeva,Sheludyakov,Ovcharuk,Kovaleva,Ustinova
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p. 469 - 477
(2008/02/07)
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- Selective oxidative carbonylation of amines to oxamides and ureas catalyzed by palladium complexes
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A new process for converting secondary amines into N,N,N′,N′- tetraalkyloxamides under CO pressure, catalyzed by homogeneous palladium complexes in the presence of 1,4-dichloro-2-butene (DCB) as an oxidant, has been developed. The mechanism of the oxidative double-carbonylation process, consisting of the oxidation of Pd(0) to Pd(11) with DCB through a β-chloride elimination of the η3-(chloromethyl) allylpalladiuni(11) intermediate, the formation of mono- and bis(carbamoyl)palladium species, and a reductive elimination of the two carbamoyl ligands, is proposed based on studies of the behavior of carbamoylpalladium complexes. When primary amines are employed with DCB as the oxidant, N,N′-dialkyloxamide is catalytically produced, whereas urea is exclusively produced when iodine is used as the oxidant. The reaction of an N-monopropylcarbamoylpalladium complex with propylamine under CO gave N,N′-dipropylurea, whereas a treatment with diethylamine yielded unsymmetrical N,N-diethyl-N′-propylurea, implying the intermediate formation of propyl isocyanate that is converted into the urea upon a reaction with the added amine. A kinetic study on the reaction of chloro-N- propylcarbamoylpalladium with triethylamine suggested a process proceeding through a base-promoted dcprolonalion of the N-monoalkylcarbamoyl ligand to form propyl isocyanate.
- Hiwatari, Kozo,Kayaki, Yoshihito,Okita, Koshi,Ukai, Tomohiro,Shimizu, Isao,Yamamoto, Akio
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p. 2237 - 2250
(2007/10/03)
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- Sulfur containing dihydrophthalazine antagonists of excitatory amino acid receptors
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Substituted dihydrophthalazine sulfur containing compositions are provided which are active as non-NMDA ionotropic excitatory amino acid (EAA) receptor antagonists. The compositions are useful for treating disorders associated with excessive activation of the non-NMDA subtype of the ionotropic EAA receptor. The compounds further are useful as testing agents to identify and characterize other compounds for the treatment of these disorders. The compounds are useful therapeutically as sedatives or for the treatment of neurosychopharmacological disorders such as stroke, ischemia and epilepsy. The compositions may be provided in combination with a suitable carrier for oral or parenteral administration. The compounds may be administered orally or parenterally for the treatment of a variety of disorders associated with non-NMDA EEA receptor function.
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- Synthesis and solid state and solution characterization of mono- and di-(η1-C) carbamoyl-palladium complexes. New efficient palladium-catalyzed routes to carbamoyl chlorides: Key intermediates to isocyanates, carbamic esters, and ureas
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The catalytic conversion of primary and secondary amines into isocyanates or carbamoyl chlorides is performed using palladium complexes. The palladium-based catalytic systems is very active and avoids the synthesis of phosgene. The palladium (II) complex
- Aresta, Michele,Giannoccaro, Potenzo,Tommasi, Immacolata,Dibenedetto, Angela,Lanfredi, Anna Maria Manotti,Ugozzoli, Franco
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p. 3879 - 3889
(2008/10/08)
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- 2-ureido-benzamide derivatives
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This invention is concerned with 2-ureido-benzamide compounds of the formula (1) STR1 in which R1 is H, halogen atom, (C1 -C4)alkyl, (C1 -C4)alkoxy or (C1 -C4)dialkylamino and R2 is H, halogen atom, hydroxy, nitro, (C1 -C4)alkyl, (C1 -C4)alkoxy, (C3 -C6) cycloalkylmethoxy, (C1 -C4) alkylthio, (C1 -C4) alkylsulfinyl, (C1 -C4)alkylsulfonyl or STR2 wherein j is an integer of from 0 to 2 and R3 and R4 are each independently H, (C1 -C4)alkyl, (C1 -C4)alkanoyl, (C1 -C4)alkylsulfonyl or (C1 -C4)alkylcarbamoyl, NR3 R4 can to form a pyrrolidine, piperidine, morpholine, imidazole or pyrazole ring; X is a (C3 -C15)alkyl, (C3 -C6) cycloalkyl, (C3 -C6) cycloalkylmethyl, ω-(C1 -C4) alkoxy-(C1 -C4) alkyl group or STR3 wherein k is an integer of from 1 to 4 and R5 and R6 are each independently H, Y is H or (C1 -C4)alkyl and Z is STR4 wherein m is an integer of from 0 to 4.
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- Reactivity of Carbamoyl Radicals. A New, General, Convenient Free-Radical Synthesis of Isocyanates from Monoamides of Oxalic Acid
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A new, general, simple synthesis of isocyanates was developed by oxidation of monoamides of oxalix acid with peroxydisulfate catalyzed by Ag and Cu salts.The reaction was carried out in a two-phase system (water and an organic solvent), and it is suitable also for practical applications, due to the simple experimental conditions and the inexpensive as well as nontoxic reagents.The first example of homolytic intramolecular aromatic carbamoylation is also reported.
- Minisci, Francesco,Fontana, Francesca,Coppa, Fausta,Yan, Yong Ming
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p. 5430 - 5433
(2007/10/02)
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- 8,9-annelated-β-carbolines and 8,9-annelated 3,4-dihydro-β-carbolines
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The invention relates to a group of new 8,9-annelated-β-carbolines and 8,9-annelated-3,4-dihydro-β-carbolines having interesting fibrinolytic properties. In particular the compounds can be used as orally active fibrinolytics. The compounds have the general formulae 1 and 2 STR1 wherein R2 +R3 together with the carbon atom and the nitrogen atom to which they are bound and the intermediate carbon atom constitute a heterocyclic group consisting of 5-10 ring atoms.
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- Process for preparing 1,3,5-triazinetriones
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The novel process STR1 gives the end products, known as animal growth-promoters and coccidiostatics. Intermediates II are new.
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- Process for preparing 1,3,5-triazinetriones
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The novel process STR1 gives the end products, known as animal growth-promoters and cooccidiostatics. Intermediates II are new.
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- Incorporation and Deoxygenation of Carbon Dioxide: A Metal-Assisted Facile Conversion of Carbon Dioxide and Primary Amines to Isocyanates
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Metal N-alkylcarbamato complexes (M = Na, n = 1; M = Mn, Co, n =2) were prepared by treating CO2 with a primary amine RNH2 (R = Ph, Cy, Pr) and various complex precursors.For M = Mn or Co and R = Cy, MCl2 can be used as starting material.These complexes were readily decomposed by acyl halides R'COCl (R' = Ph, Me), and two reaction pathways were observed.One led to decarboxylation and formation of amides RNHC(O)R', while the other afforded isocyanate RNCO and carboxylic acid (M = Na) or carboxylic anhydride (M = Mn, Co).Analysis of the reaction products showed that the metal plays a major role in the formation of the isocyanate, intercepting one of the reaction products.A mechanistic rationalization is proposed.
- Belforte, Antonio,Dell'Amico, Daniela Belli,Calderazzo, Fausto
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p. 1891 - 1898
(2007/10/02)
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- Kinetics of the Decomposition of Aliphatic Acyl Azides
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The kinetics of the decomposition of a series of aliphatic acyl azides have been investigated.The first-order rate constants and activation parameters have been determined and the influence of the substituents and of solvent polarity on the rate of decomposition has been established.
- Zlobin, V. A.,Tarasov, A. K.
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p. 140 - 141
(2007/10/02)
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- Preparation of aliphatic isocyanates
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Organic isocyanates are prepared by thermal decomposition of N,N'-disubstituted allophanic acid esters in an organic carbonate at from 150° to 400° C. The isocyanates obtainable by this process are valuable starting materials for the preparation of crop protection agents, pesticides, dyes, synthetic resins, plastics, textile waterproofing agents, detergents, bleaching agents and adhesives.
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- Process for the preparation of an aliphatic monoisocyanate
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This invention relates to an improved process for the preparation of an aliphatic monoisocyanate from the corresponding carbamic acid chloride. The carbamic acid chloride is reacted with an active hydrogen compound. The reaction is conducted in the presence of a solvent which is inert under the reaction conditions. Addition compounds are formed with the elimination of hydrogen chloride. The addition compounds are subsequently decomposed by heat into the desired isocyanate with the mixture also containing the active hydrogen compound. The monoisocyanate is subsequently removed by distillation.
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- Preparation of organic isocyanates
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A process for the manufacture of organic isocyanates which comprises reacting a substituted urea having at least one unsubstituted NH2 group with nitrous acid in the presence of a water-immiscible solvent and a phase transfer agent.
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- Optical brightening agents of naphthalimide derivatives
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A naphthalimide derivative having the formula STR1 wherein R is an alkyl, or cycloalkyl, an aralkyl, a haloalkyl, an alkoxyalkyl, a hydroxyalkyl, an N,N-dialkylaminoalkyl, an unsubstituted or halogen-, alkyl-, alkoxy- or hydroxy-substituted aryl, or an ammoniumalkyl; X is a group of the formula, STR2 wherein A is STR3 or an unsubstituted or halogen-substituted arylene, or a group of the formula, STR4 wherein R1 is hydrogen, an alkyl, phenyl, a hydroxyalkyl, or an alkoxyalkyl; Y is --CO--, --COO--, --CONR3 -- (where R3 is hydrogen or an alkyl), or --SO2 --; R2 is hydrogen, an alkyl, a cycloalkyl, an aralkyl, a haloalkyl, an alkyl- or aryl-substituted amino-alkyl, an unsubstituted or halogen-, alkyl-, alkoxy-, hydroxy-, amino- or alkylamino-substituted aryl, a group of the formula, STR5 (where R, R1 and Y are as defined above and R4 is a bivalent group), or a group of the formula, (where R5 is direct linkage or a bivalent group; Q+ is a substituted ammonium, a cycloammonium or a hydrazinium; and α- is an anion), Which is useful for optically brightening an organic polymer material.
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- Halosilyl carbamates
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Isocyanates are prepared directly from amines in a facile process which involves the reaction with halosilyl compounds to form novel halosilyl carbamates. The isocyanate may then be derived from the carbamate intermediate by gentle heating. In accordance with one aspect of the invention, isocyanates can be formed which contain a further reactive functional moiety, such as hydroxyl, amino, mercapto, nitro, sulfonamido, amido, carboxyl or the like.
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- Manufacture of alkyl isocyanates
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Aliphatic isocyanates are manufactured by thermal decomposition of aliphatic carbamic acid halides, an inert gas being passed in during the decomposition and being removed together with the hydrogen halide formed. The isocyanates which may be manufactured by the process of the invention, particularly ethyl isocyanate, n-propyl isocyanate and isopropyl isocyanate, are valuable starting materials for the manufacture of plant protection agents, pesticides, dyes, synthetic resins, plastics, hydrophobic agents for textiles, detergents, bleaches and adhesives.
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