Carboxyfullerene, a water-soluble carboxylic acid derivative of a fullerene, was investigated as a protective agent against iron-induced oxidative stress in the nigrostriatal dopaminergic system of anesthetized rats. Intranigral infusion of exclusive carboxyfullerene did not increase lipid peroxidation in substantia nigra or deplete dopamine content in striatum. Infusion of ferrous citrate (iron II) induced degeneration of the nigrostriatal dopaminergic system. An increase in lipid peroxidation in substantia nigra as well as decreases in K ϩ -evoked dopamine overflow and dopamine content in striatum were observed 7 days after the infusion. Co-infusion of carboxyfullerene prevented iron-induced oxidative injury. Furthermore, tyrosine hydroxylase-immunoreactive staining showed that carboxyfullerene inhibited the iron-induced loss of the dopaminergic nerve terminals in striatum. The antioxidative action of carboxyfullerene was verified by in vitro studies. Incubation of brain homogenates increased the formation of the Schiff base fluorescent products of malonaldehyde, an indicator of lipid peroxidation. Both autooxidation (without exogenous iron) and iron-induced elevation of lipid peroxidation of brain homogenates were suppressed by carboxyfullerene in a dose-dependent manner. Our results suggest that intranigral infusion of carboxyfullerene appears to be nontoxic to the nigrostriatal dopaminergic system. Furthermore, the potent antioxidative action of carboxyfullerene protects the nigrostriatal dopaminergic system from iron-induced oxidative injury. Key Words: Carboxyfullerene -Iron-Oxidative injury-K ϩ -evoked dopamine overflow-Lipid peroxidation.
The effect of a water-soluble malonic acid derivative of carboxyfullerence (C60) against Escherichia coli-induced meningitis was tested. C60 can protect the mice from E. coli-induced death in a dose-dependent manner. C60 administered intraperitoneally as late as 9 h after E. coliinjection was still protective. The C60-treated mice had less tumor necrosis factor alpha and interleukin-1β production by staining of brain tissue compared to the levels of production for nontreated mice. The E. coli-induced increases in blood-brain barrier permeability and inflammatory neutrophilic infiltration were also inhibited. These data suggest that C60 is a potentially therapeutic agent for bacterial meningitis.
The synthesis and spectroscopic characterization of a novel bisazafulleroid (12) and aza-aziridinofulleroid (13) are described. Treatment of C 60 fullerene with the C 2 -chiral bisazide 11 in refluxing chlorobenzene afforded bisazafulleroid 12 in 20 % yield. When a solution of 12 was exposed to ambient light a quantitative conversion to the more polar 13, in which the two imino groups add at both [5,6] and [6,6]-ring junctions, was observed. The two compounds exhibited characteristic absorption profiles in the electronic spectra and also showed distinct CD curves. Further, thermolysis of 13 in refluxing toluene resulted in a clean conversion to 12 within 10 min.15 N-labeled 12 and 13 were synthesized to establish the structures. These observations provide the first example of an interconversion between an azaand an aziridinofulleroid.
A novel class of crown ether derivatives incorporating D-glucose and poly(ethy1ene glycol) units has been synthesized from allyl a-D-glucopyranoside by a simple and efficient strategy. The complexing properties of these compounds with alkali metal cations and ammonium ion have been evaluated by Cram's picrate method. Catalytic activity of macrocycle 2 in asymmetric Michael addition reaction was also studied. The average cavity size of these macrocycles was determined by the application of the MMX programme.
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