V. S. Romanova

Membranotropic properties of the water soluble amino acid and peptide derivatives of fullerene C60.

The modifying effects of the products of the equimolar addition of dl‐alanine and dl‐alanyl‐dl‐alanine to fullerene C60 on the structure and permeability of the lipid bilayer of phosphatidylcholine liposomes has been studied using the luminescence probe technique. It is shown that these water soluble amino acid and dipeptide derivatives of fullerene (C60‐AD) are quenchers of pyrene fluorescence and erythrosine phosphorescence of in both a water solution and liposomes. To study the permeability of the lipid bilayer a procedure based on the triplet probe technique has been developed. It has been found that the C60‐AD derivatives under study are able to localize inside the artificial membrane, to penetrate into the liposomes through the lipid bilayer and to perform activated transmembrane transport of bivalent metal ions.

A graphite oxide-based nickel catalyst for reductive dechlorination of polychlorinated aromatic hydrocarbons

Heterogeneous Ni-containing catalysts based on graphite oxide were prepared and their activity in the dechlorination of polychlorinated aromatic hydrocarbons by different organosilanes was studied.

Dependence of the degree of association of water-soluble amino acid and peptide derivatives of fullerene[60] on pH and the ionic strength of a solution

The dependences of the degree of association of water-soluble amino acid and peptide derivatives of fullerene[60] on pH and the ionic strength of a solution were studied by the diffusion method. The degree of association of alanine, serine, arginine, and alanylalanine derivatives of fullerene increases both in acidic and in alkaline media compared to the initial aqueous solution. Using arginine and alanylalanine derivatives of fullerene as an example, it was demonstrated that the degree of association also increases as the ionic strength of a solution increases.

Heat capacities of aqueous solutions of amino acid and dipeptide derivatives of fullerene

The concentration dependences of heat capacities of aqueous solutions of several amino acid and peptide derivatives of fullerene were measured by scanning differential calorimetry at 298 K. The heat capacities for the arginine, alanylalanine, and glycylvaline derivatives dissolved in water depend slightly on concentration. The concentration dependences of the heat capacities of aqueous solutions of the serine and alanine derivatives display extrema. The calculated contributions of hydration to the heat capacities of the dissolved fullerene derivatives have both positive and negative signs.

AMINO ACID AND PEPTIDE DERIVATIVES OF FULLERENE

A general method for the synthesis of amino acid and peptide derivatives of fullerene (ADF) was developed, and the physicochemical properties of the compounds obtained were studied. ADF were shown to penetrate into liposomes and to exhibit adjuvant properties and antiviral activity.

Design of a hybrid nanostructure based on fullerene C60 and biologically active substance for modeling physiological properties of compounds

The effects of cognitive-stimulating substance BD-2 of the γ-carboline family and a hybrid compound based on fullerene C60 and attached BD-2 on various aspects of the behavior of animals were studied. The synthesized hybrid fullerene compound (HFC) has no side psychostimulating effect characteristic of BD-2 but fully retains the properties of a cognitive-stimulating agent. The design of hybrid compounds based on fullerene C60 and pharmacologically active groups can be one of the ways for optimizing therapeutically promising compounds.

Membranotropic properties of fullerene-containing amphiphilic (co)polymers of N-vinylpyrrolidone

The effect of fullerene-containing amphiphilic (co)polymers of N-vinylpyrrolidone (C60/PVP) differed in composition and topology of the polymer chains on the membrane structure of phosphatidylcholine liposomes was studied. Using the method of fluorescent probes it was found that the C60/PVP structures under study are localized in the phosphatidylcholine membrane in the region of glycerol fragments and fatty acid chains of phospholipids. The C60/PVP copolymers form complexes with 2,7-dibromoproflavin and pyrene probes. The effective equilibrium constants of the probe–C60/PVP complexes in aqueous solutions and in the liposome membrane were determined. It is most likely that the fullerene-containing (co)polymers of N-vinylpyrrolidone form complexes not only with fluorescent probes but also with phospholipids of the liposome membrane, which reduces the stability of the probe–C60/PVP complex.