Yu. V. Kiseleva

Comparative study of self-organization and physicochemical properties of highly diluted aqueous solutions of phenol bioantioxidants

203 Applying a methodological approach suggested by us to different compounds (organic and inorganic salts, amphiphilic and lipophilic compounds), physic ochemical substantiation of the effect of ultralow con centrations and electromagnetic fields has been devel oped for the first time. This substantiation makes it possible to work out a convincing concept of the exist ence of nonlinear changes in physicochemical proper ties (electrical conductivity, surface tension, pH, cata lytic activity) and of the appearance of bioeffects of solutions of biologically active compounds (BACs) in the range of low and ultralow concentrations [1–6]. The effect consists in solute initiated formation of nanosized (D up to 400 nm, ζ potential ranges from –2 to –20 mV) structures (nanoassociates) composed mainly of water molecules in aqueous solutions of dif ferent compounds of ultralow concentration. The change in the nanoassociate parameters (D, ζ poten tial) with a change in the solute concentration corre lates with the concentration induced change in the physicochemical and biological properties of solu tions. Compounds capable and incapable of exhibiting this effect have been discovered. However, it is still unclear how the structure of a compound affects the formation of nanoassociates and physicochemical properties of solutions of low concentration. With the aim of elucidating the effect of the struc ture of a compound on the formation of nanoassoci ates, in this work, we studied the self organization and physicochemical properties of solutions of some 2,6 dialkylphenol derivatives—synthetic potassium phe nosan (1) and Ichphan C 10 (2) and natural α toco pherol (3)—capable of forming nanoassociates [1, 2, 5, 6] and manifesting biological activity in highly diluted aqueous solutions [7–11]. The selected com pounds have a sterically hindered hydroxyl group responsible for the antioxidant properties of com pounds 1–3 and different substituents in the benzene ring responsible for hydrophilicity (1), amphiphilicity (2), and hydrophobicity (3) of these BACs.

Dielectric spectroscopy study of low-concentration aqueous solutions of a calix[4]resorcinarene derivative

ISSN 00125016, Doklady Physical Chemis try, 2014, Vol. 455, Part 2, pp. 56–59.

Self-organization and properties of dilute aqueous solutions of cetyltrimethylammonium bromide in a range of physiologically important temperatures

A combination of physicochemical methods (dynamic light scattering, nanoparticle tracking analysis, conductometry, tensiometry, and ESR spectroscopy) revealed that dilute solutions (1•10–3, 1.0•10–4, 1.0•10–7, and 1.0•10–9 mol L–1) of surfactant (cetyltrimethylammonium bromide) in a temperature range of 25—45 °C are self-organized dispersed systems. As the temperature increases, the systems undergo rearrangements specific for each studied concentration, which is reflected as nonmonotonic temperature dependences of the parameters of domains (1•10–3 and 1.0•10–4 mol L–1) and nanoassociates (1.0•10–7 and 1.0•10–9 mol L–1) and also as interrelated dependences of the conductivity of solutions with extremes at 30, 37, and 40 °C. The ESR experiments show a nonmonotonic decrease in the rotational diffusion correlation time (τcor) of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) in the temperature dependences of τcor with the temperature increase from 25 to 45 °C and the appearance of two to three plateaus, one of which (in a range of 36—40 °C) is observed in the temperature dependences for all studied concentrations.

Influence of spatial isomerism of tetrathiacalix[4]arene functionalized by hydrazide groups on self-organization and physicochemical properties of aqueous dimethyl sulfoxide solutions of low concentration

264 Recently, we have discovered a new phenomenon that opens the way to elucidating the mechanism of the effect of weak action of different nature on living organisms [1–5]. This phenomenon, referred to as “effect of ultralow concentrations and electromag netic fields” [2], consists in the formation of nano sized molecular ensembles, so called nanoassociates, in aqueous solutions of low concentrations. The nanoassociate formation is responsible for the emer gence of unique physicochemical properties of dilute solutions and, which is especially important, corre lates with bioeffects of these solutions [3, 4]. Forma tion of nanoassociates is initiated by a solute under certain conditions, the most essential among which are the presence of external electromagnetic fields and a definite structure of a substance [5].

The ability of green fluorescent proteins for photoconversion under oxygen-free conditions is determined by the chromophore structure rather than its amino acid environment

Photoconversion of various green and cyan fluorescent proteins to the red fluorescent state under the oxygen-free conditions was studied. Such photoconversion has earlier been described for the EGFP green fluorescent protein. Phylogenetically distant fluorescent proteins that have a low identity of their amino acid sequences but contain chemically identical chromophores based on a Tyr residue were shown to be susceptible to this type of photoconversion. At the same time, the ECFP protein, which has 92% homology with EGFP but contains a chromophore based on tryptophan did not undergo the photoconversion. Thus, it is precisely the chromophore structure, rather than the amino acid environment that determines the ability of green fluorescent proteins to display photoconversion to the red fluorescent state under anaerobic conditions.

Forming the nanosized molecular assemblies (nanoassociates) is a key to understand the properties of highly diluted aqueous solutions

In the present study it was shown that biological effects of highly diluted aqueous solutions were due to the formation of nano-sized (up to 400 nm) molecular assemblies, called nanoassociates mainly consisting of aqueous molecules (up to 500 million) under the influence of two effectors: solute and external electromagnetic fields.

Self-organization and physicochemical properties of aqueous solutions of the antibodies to interferon gamma at ultrahigh dilution

It has been recently shown that manifestation of nonmonotonic concentration dependences of physicochemical properties of highly diluted solutions (10 –20 –10 –6 mol/L) of biologically active compounds (BACs) correlating with their bioeffects is caused by formation and rearrangement of nanoobjects (100– 400 nm), referred to as nanoassociates (see review [1] and references therein). It has been revealed that nanoassociates are initiated by a solute under certain conditions, the most essential among which are the presence of external electromagnetic fields, the defi� nite structure of the solute, and the procedure of prep� aration of solutions. In highly diluted BAC solutions kept in a permalloy container, i.e., at reduced levels of external physical fields, nanoassociates are not formed and the properties of solutions correspond to the prop� erties of the solvent, water. Based on analysis of data

Relationship between self-organization and biological activity of highly diluted solutions of a tetrahydrazide tetrathiacalix[4]arene derivative

In the course of systematic study of self-organization and properties of diluted solutions of biologically active compounds (BACs), an unknown phenomenon has been discovered. Using a complex of physicochemical methods, it has been shown for the first time that diluted aqueous solutions of many BACs in a wide range of calculated concentrations (10–6–10–20 mol/L), prepared by serial tenfold dilution from a stock solution, are self-organized disperse systems in which the disperse phase is represented by nanosized molecular ensembles (up to 400 nm) denominated nanoassociates [1].

Highly diluted solutions of amphiphilic derivatives of calix[4]resorcinols: self-organization and physicochemical properties

Self-organization and physicochemical properties of highly diluted solutions (10−11–10−2 mol L−1) in aqueous DMF (30 vol.% DMF) of a series of octasubstituted amphiphilic calix[4]resorcinols (CRs 1–4, where 1 is CR with carboxymethyl groups, 2 is its potassium salt, and 3 and 4 are CRs with acetylhydrazide and tris(hydroxymethyl)methylamide fragments) stored both under natural conditions and in the absence of external physical fields (geomagnetic and low-frequency electromagnetic) were studied by a complex of methods (dynamic light scattering, electrophoresis, tensiometry, conductometry, and pH metry). The studied solutions of CRs 1–4 are dispersed systems in which micelles (for CRs 1, 2, and 4), supramolecular domains (for CRs 1–4), and nanoassociates (for CRs 2–4) are formed, depending on hydrophilicity and nature of functional groups of CRs in various concentration ranges. The new approach to studying highly diluted solutions made it possible to explain for the first time the reasons for the nonmonotonic changes in the physicochemical properties and surface activity of aqueous-dimethylformamide highly diluted solutions of amphiphilic calix[4]resorcinols (10−4–10−7 mol L−1) from the viewpoint of the formation and rearrangement of supramolecular domains and nanoassociates.