55738-70-0Relevant academic research and scientific papers
Functionalization of luminescent lanthanide-gallium metallacrowns using copper-catalyzed alkyne-azide cycloaddition and thiol-maleimide Michael addition
Lutter, Jacob C.,Lopez Bermudez, Beatriz A.,Nguyen, Tu N.,Kampf, Jeff W.,Pecoraro, Vincent L.
, p. 119 - 125 (2019/01/15)
The synthesis and characterization of {Ln[12-MCGa III N(eshi)-4]}2(iph)4 and {Ln[12-MCGa III N(shi)-4]}2(miph)4 metallacrowns (MCs), where shisu
LN(III) AND GA(III) METALLACROWN COMPLEXES
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Page/Page column 34, (2016/12/12)
The present invention concerns heterometallic metallacrown compounds incorporating Ga(lll) and Ln(lll) cations, with a templating ligand such as salicylhydroxamic acid or derivatives thereof, wherein said metallacrown contains at least one repeating [-Ga-N-O-] sub-unit where the N-0 derives from the templating ligand.
Design, synthesis, and biochemical evaluation of N-substituted maleimides as inhibitors of prostaglandin endoperoxide synthases
Kalgutkar, Amit S.,Crews, Brenda C.,Marnett, Lawrence J.
, p. 1692 - 1703 (2007/10/03)
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.
