Supramolecular systems based on alkylated p-sulfonatocalix[n]arenes: aggregation and catalytic and biological activity

Abstract

Aggregation, catalytic activity, and the influence of alkylated p sulfonatocalix[n]arenes (SCA; n = 4, 6, 8) on the energy exchange in cells of wheat roots were studied. In water SCA are surfactants, and their efficiency changes with an increase in the number of aromatic rings (n) and the length of hydrocarbon substituents (R) in the molecule. In the range of critical micelle concentration, SCA form micelles with an effective hydrodynamic diameter of ~200 nm. The catalytic activity of micellar solutions of SCA (n = 4, 8; R = C 12 H 25 ) in hydrolysis of ethyl 4 nitrophenyl chloromethylphosphonate (ENCP) decreases with an increase in n, whereas the binding constant of ENCP increases. The modifying effect of SCA on the membranes and the energy exchange in cells of wheat roots was revealed: the membranotropic activity of SCA increases with an increase in the hydrophobicity of substituents R and the macrocycle size.Considerable attention is recently given to the study of methods for synthesis, properties, and the scope of application of p sulfonatocalix[n]arenes (SCA) and their derivatives. 1-16 One of the most promising and interest ing directions of using SCA is the medical biological area, 17 which is caused by high solubility of SCA in water, low toxicity, 17 and accessibility of functionalization, which makes it possible to control physicochemical properties of these compounds by changing the nature of substituents and the number of aromatic rings. For instance, the in troduction of alkyl radicals into the SCA molecule favors the change in its hydrophilic lipophilic balance and the appearance of surfactant properties. 1,4 A consequence of an increase in the number of aromatic rings is the confor mational mobility of the macrocycle, 5,6,9-11,17 resulting in the appearance of the adaptive ability to substrate binding (flexible "tuning"). 18 Although many publications are de voted to p sulfonatocalix[n]arenes, the aggregation be havior of SCA modified by alkyl radicals was not system atically studied.The mechanism of interaction of biologically active compounds with the cell membrane surface depends, to a great extent, on hydrophobicity of these compounds and their aggregation state. 19-22 Many micelle forming sur factants possess antimicrobial activity and can enhance the effect of sulfamide drugs and solubilize hydrophobic drugs by transforming them into the soluble form. 19,23 It is known that the energy processes in cells are tightly related to the phosphorylation dephosphorylation reactions of membrane proteins. 24 The study of biological aspects of application of nonmodified p sulfonatocalix[n]arenes showed that unsubstituted SCA (n = 4, R = Н) manifest supramolecular catalytic activity in hydrolysis of ATP, 17 which can change substantially in the case of alkylated SCA. Therefore, the complex study of the aggregation properties of alkylated SCA, their catalytic activity in the model reaction of hydrolysis of phosphorus acid esters, and the influence on biosystems is an urgent problem, whose solution will hel...

Disperse Systems Based on a Dodecyl Derivative of p-Sulfonatocalix[6]arene: Self-Organization and Physicochemical Properties in a Wide Range of Concentrations and Temperatures

“…As stated before, [6] the former are micelles, and the critical micelle concentration (CMC) is 6·10 -4 М. In the concentration range from 1·10 -9…”

“…Keywords: Sulfonatocalix [6]arene, dodecyl derivative, aqueous disperse systems, self-organization, physicochemical properties.…”

“…both of the dispersed phase and the dispersion medium, which is most pronounced in the concentration ranges of about 1·10 -4 -1·10 -5 M and 1·10 -7 -1·10 -9 M. In order to obtain additional information on the structural rearrangement of the system 1 and the properties of the dispersed phase in various ranges of concentrations and temperatures, the heat capacity of aqueous systems based on 1 in the concentration range 1·10 -3 -1·10 -9 M in the range of 10-90 °C was studied by differential scanning microcalorimetry, as well as of 1 systems, subjected to long-term storage (for 8 months). From the experimentally observed specific heat capacity of the solution (c P ), the excess partial specific heat of 1 in an aqueous solution ( 2 E P, c ) was found and analyzed, calculated analogous to [25,26] , which is the differential characteristic of the dissolved substance that most clearly reflects the structural rearrangements in the solution with respect to the dissolved substance, associated Disperse Systems Based on p-Sulfonatocalix [6]arene with the formation and destruction of the associates of "dissolved substance -solute" and "dissolved substancesolvent" kinds. The dependence of…”

“…[1] Utilizing the above-described original approach for studying the disperse systems allowed for an experimentally proved differentiation of the disperse phase's nature, which often has a similar size of hundreds of nanometers, and it also can be useful for studying the supramolecular systems containing BAS of complex structure, e.g. the systems based on an intensively studied in the last decades calixarenes, [5][6][7] for which a complicated nonmonotonic change of the physicochemical properties is often observed with the decrease in concentration. Studies [8][9][10] managed to explain the causes of nonmonotonic changes in the concentration dependencies of the specific electrical conductivity, surface tension, and bioeffects in water-organic systems based on amphiphilic calix [4]resorcinols (10 -4 -10 -7 M) and amphiphilic acetylhydrazide derivative of 4-tert-butyltetrathiacalix [4]arene in the cone and 1,3-alternate conformations (10 -4 -10 -8 M) from the perspective of formation and rearrangement of supramolecular domains and nanoassociates.…”

“…The aim of this work was to study the self-organization and properties of a water-soluble dodecyl derivative of the p-sulfonatocalix [6]arene (1) that has a vast scope of applications [5][6][7] using a complex of physicochemical methods (dynamic light scattering -DLS, nanoparticle tracking analysis -NTA, tensiometry, differential scanning calorimetry -DSC), which can help to find the concentration ranges of different disperse phases' formation, define their behavior patterns and explain the properties of 1 solutions in a wide range of concentrations (1·10 …”