Synthesis of Various Water-Soluble C60 Derivatives and Their Superoxide-Quenching Activity

In order to examine the utility of fullerene as a medicinal application, we evaluated the reaction between fullerene derivatives and active oxygen species in vitro. This paper describes the synthesis of various water-soluble C₆₀ derivatives (cationic and anionic) and evaluation of their superoxide (O₂^-) quenching activity. Cationic C₆₀ derivatives showed fairly high efficiency.     

Synthesis of Various Water-Soluble G60 Derivatives and Their Superoxide-Quenching Activity

In order to examine the utility of fullerene as a medicinal application, we evaluated the reaction between fullerene derivatives and active oxygen species in vitro. This paper describes the synthesis of various water-soluble C₆₀ derivatives (cationic and anionic) and evaluation of their superoxide (O₂^-) quenching activity. Cationic C₆₀ derivatives showed fairly high efficiency.     

Synthesis of Various Water-Soluble G60 Derivatives and Their Superoxide-Quenching Activity

Abstract

In order to examine the utility of fullerene as a medicinal application, we evaluated the reaction between fullerene derivatives and active oxygen species in vitro. This paper describes the synthesis of various water-soluble C₆₀ derivatives (cationic and anionic) and evaluation of their superoxide (O₂ ^?) quenching activity. Cationic C₆₀ derivatives showed fairly high efficiency.     

Highly Water Soluble C60 Derivatives: A New Synthesis

Unprecedented protocol, consisting in reduction of Buckminsterfullerene with Na/K alloy and successive stirring in presence of O₂, affords polyhydroxylated fullerenols which are highly water soluble, from strongly basic to medium acidic conditions. The products have been characterized by means of cross polarization magic angle spinning (CPMAS) NMR, ¹H-NMR, electron, FT-IR, Raman and mass spectroscopies. Possible paths of reaction and the role of molecular oxygen in fullerene cage-oxidation are discussed.     

Highly Water Soluble C60 Derivatives: A New Synthesis

Abstract

Unprecedented protocol, consisting in reduction of Buckminsterfullerene with Na/K alloy and successive stirring in presence of O₂, affords polyhydroxylated fullerenols which are highly water soluble, from strongly basic to medium acidic conditions. The products have been characterized by means of cross polarization magic angle spinning (CPMAS) NMR, ¹H‐NMR, electron, FT‐IR, Raman and mass spectroscopies. Possible paths of reaction and the role of molecular oxygen in fullerene cage‐oxidation are discussed.     

Hydroxyl Radical Scavenging and Producing Activities of Water-Soluble Malonic Acid C60

Abstract

The effects of several water-soluble malonic acid derivatives of C₆₀ with different addition number (M1～M4) on hydroxyl radical were studied by ESR method. It was shown that the OH signal produced by the Fenton system could be remarkably reduced by M1 and M2, but could not by M3 and M4. The action of M1 and M2 was dose-dependent, and M1 was found to be more effective than M2. In addition, under irradiation and in the presence of oxygen, M2 could produce hydroxyl radicals. These data indicate that the quenching activity of the malonic acid derivative of C₆₀ was closely related to the integrity of conjugated double bonds, and some C₆₀ derivatives with specific structures might act as the eliminator or producer of hydroxyl radicals under different conditions.     

Hydroxyl Radical Scavenging and Producing Activities of Water-Soluble Malonic Acid C60

The effects of several water-soluble malonic acid derivatives of C₆₀ with different addition number (M1∼M4) on hydroxyl radical were studied by ESR method. It was shown that the OH signal produced by the Fenton system could be remarkably reduced by M1 and M2, but could not by M3 and M4. The action of M1 and M2 was dose-dependent, and M1 was found to be more effective than M2. In addition, under irradiation and in the presence of oxygen, M2 could produce hydroxyl radicals. These data indicate that the quenching activity of the malonic acid derivative of C₆₀ was closely related to the integrity of conjugated double bonds, and some C₆₀ derivatives with specific structures might act as the eliminator or producer of hydroxyl radicals under different conditions.     

Infrared Spectra and Structure of C60 Heterocyclic Derivatives

Abstract

Infrared spectra of a number of C₆₀ cycloaddition products, namely, fullerenopyrroline and fullerenopyrazolines with the substituents in the heterocyclic fragments have been studied experimentally and employing DFT calculations. Complete vibrational assignment is proposed.     

Synthesis of Heterocycle-Containing [60]Fullerene Derivatives

Abstract

Fullerene functionalization with heterocycles is reviewed, focusing attention on cycloaddition methodology and oxidative heterocyclization. ^{1 1}This paper was presented before the Symposium 3 on ‘Expanded Horizons of Fullerene Science and Technology’ organized by L. Y. Chiang, E.Osawa, H. Terrones and M. Saunders at the 4th International Conference on Advanced Materials (ICAM-IV), Aug. 27 to Sept. 1, 1995, Cancun, Mexico.

     

Synthesis of Heterocycle-Containing [60]Fullerene Derivatives

Fullerene functionalization with heterocycles is reviewed, focusing attention on cycloaddition methodology and oxidative heterocyclization.¹     

Preparation of Two Novel C60 and C70 Fullerene Pyrrolidine Derivatives

Abstract

C₆₀ reacted with paraformaldehyde and DL-valine in dry toluene under nitrogen to give a monoadduct. Under the similar conditions,C₇₀ gave a bisadduct. Both products were characterized by FT-IR,UV-Vis,EI-MS and NMR.The studies of the cyclic voltammetry showed that the abilities of donating electron of the products were increased compared to C₆₀ and C₇₀ respectively.     

Structures, Stabilities and Strain in C60 and C70 Derivatives

The stabilities of a number of small adducts as well as larger hydrides of C₆₀ and C₇₀ are reported using semiempirical MO methods. The data are shown to be consistent with the nature of bond alternation in the parent fullerenes and strain effects in the cage systems.     

Preparation of Two Novel C60 and C70 Fullerene Pyrrolidine Derivatives

C₆₀ reacted with paraformaldehyde and DL-valine in dry toluene under nitrogen to give a monoadduct. Under the similar conditions,C₇₀ gave a bisadduct. Both products were characterized by FT-IR,UV-Vis,EI-MS and NMR.The studies of the cyclic voltammetry showed that the abilities of donating electron of the products were increased compared to C₆₀ and C₇₀ respectively.     

Two Methods to Synthesize C60Nitroxide Derivatives

C₆₀derivatives covalently linked with the nitroxide radical of 2,2,6,6-tetramethylpiperidine-1-oxyl have been synthesized by two methods: C₆₀ reacts with 4-amino-4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TOAC) and aldehyde; And another new route: C₆₀ reacts with 4-oxo-2,2,6,6-tetramethyl-piperidinyloxy(4-oxo-TEMPO) and amino acid.     

双二硫代亚乙基四硫代富瓦烯衍生物的合成及其LB膜的制备

合成了带双烃锘及双甲酸甲酯基取代的两种双二硫代亚乙基甲硫代富瓦烯（ＢＥＤＴ＝－ＴＴＦ）的衍生物及其的ＴＣＮＱ的ＣＴ－络合物。制备瓣Ｌ膜并测试膜的导电率。由于单分子膜与各层膜相比分子列紧密程度不同。平行ＬＢ 导电率比垂直于ＬＢ膜方向的导电率高近１０＾７个数量级。     

Synthesis of Radiolabeled Fullerenes C60 and C70

The synthesis of radiolabeled C₆₀/C₇₀ for potential biochemical tracer studies was carried out. Vaporization under plasma are conditions (~3000C) of graphite rods impregnated with the ¹⁴C labeled steroid progesterone generates the expected C₆₀/C₇₀ mixture. Isolation and characterization of the ¹⁴C-C₆₀ is reported. Interestingly, the C₇₀ had more radioactivity than the C₆₀.     

Penetration of Fullerene C60 Derivatives Through Biological Membranes

Penetration of fullerene C₆₀ in hydrated molecular-colloidal form (FMC) and various C₆₀ water-soluble derivatives (FDs) through membranes of human erythrocytes, platelets and symbiosomes (subcellular organelles of plant origin) were tested. The FDs bearing amino acids induced pronounced depolarization of symbiosome membranes energized with Mg-ATP. In erythrocytes and platelets incubated in K⁺-free medium in the presence of FCCP, FDs with malonic acid pendants promoted acidification of the intracellular medium thereby simulating an effect of the K⁺ ionophore valinomycin. Dissipation of ΔpH artificially induced on the plasma membrane of these cells was observed in the presence of C₆₀-γ-aminobutiric acid which, in addition, strongly stimulated Mg-ATP-dependent generation of membrane potential on symbiosome membranes. C₆₀-Arg was shown to dissipate K⁺-diffusion potential on erythrocyte membranes induced by valinomycin. Fullerene C₆₀ used in hydrated molecular-colloidal form (FMC) also entered symbiosomes and platelets as evidenced by the quenching of the fluorescence of the Ca²⁺ indicator chlorotetracycline localized in the interior of these cells. These findings provide evidence for ease of permeation of these fullerene-based compounds through biological membranes from different type cells.     

Synthesis of Radiolabeled Fullerenes C60 and C70

Abstract

The synthesis of radiolabeled C₆₀/C₇₀ for potential biochemical tracer studies was carried out. Vaporization under plasma are conditions (~3000C) of graphite rods impregnated with the ¹⁴C labeled steroid progesterone generates the expected C₆₀/C₇₀ mixture. Isolation and characterization of the ¹⁴C-C₆₀ is reported. Interestingly, the C₇₀ had more radioactivity than the C₆₀.     

Synthesis of C60-Furfural Adduct

Abstract

Diels-Alder cycloaddition of furfural to C₆₀ in toluene has been realised. UV-VIS, FTIR and ¹H-NMR investigations suggest that the conjugated structure of furfural was changed into a non-conjugated structure in the product.     

Synthesis of C60-Furfural Adduct

Diels-Alder cycloaddition of furfural to C₆₀ in toluene has been realised. UV-VIS, FTIR and ¹H-NMR investigations suggest that the conjugated structure of furfural was changed into a non-conjugated structure in the product.