- Synthesis, anticholinesterase activity and structure-activity relationships of m-Aminobenzoic acid derivatives
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The synthesis, acetylcholinesterase inhibitory capacity and structure-activity relationships of simple-structured m-Aminobenzoic acid derivatives are reported. Compound 1b was found to be more potent than galanthamine and tacrine in inhibiting acetylcholinesterase.
- Trujillo-Ferrara, Jose,Montoya Cano, Leticia,Espinoza-Fonseca, Michel
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- Bismaleimide monomers with various structures and polyaspartimides
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A series of bismaleimide monomers with various structures were synthesized by the reaction of bisphenols or diamines with 3 or 4- maleimidobenzoyl chloride. The reaction of these bismaleimides with aromatic diamines (Michael addition) yielded polyaspartimides. The monomers and polymers were characterized by FTIR and 'H-NMR spectroscopy and elemental analysis. Thermal characterization of monomers and polymers was accomplished by differential scanning calorimetry and dynamic thermogravimetric analysis. Some of the mechanical properties of the films based on these polymers were studied.
- Sava, Mitica
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p. 929 - 937
(2013/09/23)
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- Solid-phase synthesis of cleavable N-arylmaleimides: Applications in 1,3-dipolar cycloaddition and in thiol scavenging
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(matrix presented) An efficient solid-phase synthesis of polymer-supported N-arylmaleimides has been developed. Various N-arylmaleimidobenzoic acids (MBA) were elaborated onto Rink and SASRIN resins by reaction of the aniline precursors with maleic anhydride followed by facile cyclative dehydration of the resulting maleimic acids. Applications of these acid-cleavable MBA resins in the solid-phase synthesis of highly decorated pyrrolidines and as thiol scavengers are presented.
- Hoveyda, Hamid R.,Hall, Dennis G.
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p. 3491 - 3494
(2007/10/03)
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- Thermal studies of bismaleimides. II Bismaleimides with ester units
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Bismaleimides containing ester groups in the backbone were synthesized from 3(4)-maleimido benzoic acid chloride with varies diphenols. These bismaleimides are characterized by DSC studies, thermogravimetric analysis and isothermal gravimetric analysis (IGA). The thermal properties of these compounds were compared.
- Sava, Miticǎ,Gǎinǎ, Constantin,Gǎinǎ, Viorica
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p. 1167 - 1173
(2007/10/03)
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- 1H and 13C NMR spectra for a series of arylmaleamic acids, arylmaleimides, arylsuccinamic acids and arylsuccinimides
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The 1H and 13C NMR spectra of 17 succinic anhydride derivatives and 25 maleic anhydride derivatives were completely assigned using one- and two-dimensional NMR techniques. Copyright
- Trujillo-Ferrara, Jose,Santillan, Rosa,Beltran, Hiram I.,Farfan, Norberto,Hoepfl, Herbert
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p. 682 - 686
(2007/10/03)
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- Design, synthesis, and biochemical evaluation of N-substituted maleimides as inhibitors of prostaglandin endoperoxide synthases
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N-(Carboxyalkyl)maleimides are rapid as well as time-dependent inhibitors of prostaglandin endoperoxide synthase (PGHS). The corresponding N- alkylmaleimides were only time-dependent inactivators of PGHS, suggesting that the carboxylate is critical for rapid inhibition. Several N-substituted maleimide analogs containing structural features similar to those of the nonsteroidal anti-inflammatory drug aspirin were synthesized and evaluated as inhibitors of PGHS. Most of the aspirin-like maleimides inactivated the cyclooxygenase activity of purified ovine PGHS-1 in a time- and concentration-dependent manner similar to that of aspirin. The peroxidase activity of PGHS was also inactivated by the maleimide analogs. The cyclooxygenase activity of the inducible isozyme, i.e., PGHS-2, was also inhibited by these compounds. The corresponding succinimide analog of N-5- maleimido-2-acetoxy-1-benzoic acid did not inhibit either enzyme activity, suggesting that inactivation was due to covalent modification of the protein. The mechanism of inhibition of PGHS-1 by N-(carboxyheptyl)maleimide was investigated. Incubation of apoPGHS-1 with 2 equiv of N-(carboxyheptyl)[3,4- 14C]maleimide led to the incorporation of radioactivity in the protein, but no adduct was detected by reversed-phase HPLC, suggesting that it was unstable to the chromatographic conditions. Furthermore, hematin- reconstituted PGHS-1, which was rapidly inhibited by N- (carboxyheptyl)maleimide, displayed spontaneous regeneration of about 50% of the cyclooxygenase and peroxidase activities, suggesting that the adduct responsible for the inhibition breaks down to regenerate active enzyme. ApoPGHS-1, inhibited by N-(carboxyheptyl)maleimide, did not display regeneration of enzyme activity, but addition of hematin to the inhibited apoenzyme led to spontaneous recovery of about 50% of cyclooxygenase activity. These results suggest that addition of heme leads to a conformational change in the protein which increases the susceptibility of the adduct toward hydrolytic cleavage. ApoPGHS-1, pretreated with N(carboxyheptyl)maleimide, was resistant to trypsin cleavage, suggesting that the carboxylate functionality of the maleimide binds in the cyclooxygenase channel. A model for the interaction of N-(carboxyheptyl)maleimide in the cyclooxygenase active site is proposed.
- Kalgutkar, Amit S.,Crews, Brenda C.,Marnett, Lawrence J.
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p. 1692 - 1703
(2007/10/03)
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- Synthesis of N-Maleoyl-aminoacids and -peptides
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N-Maleoyl-aminoacid-N'-hydroxysuccinimidesters 3 or N-maleoyl-aminobenzoic acids 5 are synthsized from N-maleyl-aminoacids 1 on different ways.N-maleoyl-aminobenzoic-4-nirophenyl-, -2-nitro-phenyl- or 2,4-dinitro-phenylesters 6, 7 and 8 will be obtained from 1 or 5. o-Mercaptoaniline, thiourea or cysteine react with 5 to benzothiazines 9, thiazolidines 10 and 1,4-thiazines 11.From 5 the peptides 12 are yielded.The pentapeptide 13 are formed from 12 by addition of glutathione.
- Augustin, Manfred,Mueller, Wolfgang
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p. 789 - 798
(2007/10/02)
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- Preparation and Characterization of Hetero-bifunctional Cross-linking Reagents for Protein Modifications
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Ten aromatic and aliphatic cross-linking reagents of hetero-bifunctional type were synthesized as part of a search for useful reagents of this type.All of the reagents possess two selectively reactive groups a maleimide group which can combine with a thiol group via its double bond and an N-Hydroxysuccinimidyl ester (one of the most hydrophilic active esters), which can react with an ammmine group.It was found that the active esters of the reagents tested were mostly more reactive with lysine than with leucine, and acylated amino acids more rapidly at pH 8.0 than at pH 7.0.It was also found that the stability of the maleimide group in the compounds tested depends largely upon the pH of the buffer used.The most stable pH was 5.0-6.0.To use one of the present compounds as a cross-linker, the crystalline reagent should be dissolved in tetrahydrofuran of dioxane and the solution used for cross-linking.The acylation step should be carried out first with thiol addition to the maleimide group as the second step.The optimum pH of the buffer used for the first step is slightly basic.The reaction time should be limited to less than 1 hr.When the first step is over, the pH of the reaction mixture should be changed to 5.0-6.0.Keywords---cross-linker; hetero-bifunctional reagent; reactivity of N-hydroxy-succinimidyl ester; stability of maleimide residue; N-(maleimidobenzoyloxy)succinimide derivative; N-(maleimidoalkyloxy)succinimide derivative
- Kitagawa, Tsunehiro,Shimozono, Takuro,Aikawa, Tadaomi,Yoshida, Toyokichi,Nishimura, Haruki
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p. 1130 - 1135
(2007/10/02)
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