Vyacheslav I. Boyko

Calixarenes in bio-medical researches.

Application of calixarene derivatives in bio-medical researches is reviewed in this article. Antiviral, bactericidal, antithrombothic, antituberculosis, anticancer activity as well as specific protein complexation, membranotropic properties and toxicity of modified calixarenes are discussed.

Synthesis and stereochemical configuration of inherently chiral p-tert-butylcalix[4]arene carboxylic acids and their derivatives

Both enantiomers of inherently chiral p-tert-butylcalix[4]arene carboxylic acids with ABHH substitution patterns have been prepared by stereoselective reaction of monopropoxy-p-tert-butylcalix[4]arene with an (R)-N-(1-phenylethyl)bromoacetamide, separation of the diastereomers by column chromatography, and removal of the chiral auxiliary groups. The absolute configuration of obtained compounds has been established by X-ray analysis.Graphical Abstract

Synthesis and stereochemical configuration of diastereomeric inherently chiral calixarenes with ABCH and ABCD type of substitution at the lower rim

By sulfonylation of tetra(p-tert-butyl)-27-propoxy-25-[N-(1-phenylethyl)carbamoylmethoxy]calix[4] arene diastereomeric inherently chiral calixarenes with the ABCH substitution at the lower rim were synthesized and separated by column chromatography. The alkylation of these compounds afforded the corresponding calixarenes with the ABCD substitution type. The absolute configuration of compounds was established by XRD analysis.

Calix[4]arenes C-136 and C-137 hyperpolarize myometrium mitochondria membranes

Calixarenes are supramolecular compounds interacting with bioactive molecules and ions, causing changes in biochemical and biophysical processes. The aim of this work was to study the effects of calix[4]arenes C-136, C-137, and C-138 at the level of polarization of the rat myometrium mitochondria membrane. The structure of synthesized calix[4]arene molecules was confirmed by the methods of 1H NMR and infrared spectroscopy. Calix[4]arenes C-136 and C-137 each possess two chalcone amide moieties at the lower rim, while calix[4]arene C-138, only one. Calix[4]arenes C-136 and C-137 differ by the presence of ether or hydroxyl groups, respectively, at the lower rim of calix[4]arene skeleton, as well as the length of alkyl spacer between chalcone amide group and the macrocycle. It was shown that calix[4]arenes C-136, C-137, and C-138 form micelles in aqueous medium and in dimethylformamide (DMF). Irradiation of micelles with an argon laser on the flow cytometer results in the rise of autofluorescence. In an aqueous medium, calix[4]arene micelles interact with a positively charged voltage-sensitive fluorescent probe TMRM, which can testify to the presence of negative charge in these structures. However, calix[4]arene micelles do not interact with TMRM in DMF solution. The mitochondrial membrane potential was measured using fluorescent dyes MTG and TMRM with confocal microscopy and fluorescent dye TMRM with flow cytometry. Experiments were conducted on myometrium cells in culture and on suspension of digitonin-permeabilized uterus myocytes. It was shown that the fluorescent signal was stable during the time of experiment. Calix[4]arenes C-136 and C-137 (10 μM) hyperpolarize mitochondria membranes. At maximum, the effect was 173% relative to the control. At the same time, calix[4]arene C-138 did not influence the mitochondria membrane potential. The relationship between the structural organization of investigated calix[4]arene molecules and their effect on polarization of the mitochondria membrane is discussed.

Chiral Phosphorus-Contained Calixarenes

Synthesis and some properties of the three-dimensional calixarene molecules functionalized with chiral aminophosphonic or hydroxyphosphonic acid residues as well as inherently chiral calixarenes are discussed. The calixarene aminophosphonic acids show inhibitory activity toward porcine kidney alkaline phosphatase that strongly depends on the absolute configuration of the α-carbon atoms.

Lowering of order and general solutions of some classes of partial differential equations

Abstract A procedure of lowering the order and a construction of general solutions for some classes of partial differential equations (PDEs) are proposed. Some classes of general solutions of some linear and nonlinear equations of mathematical physics are constructed and a series of examples is presented.

Design, synthesis and structure determination of new inherently chiral para-bromoalkoxycalix[4]arenes

Abstract The preparative method for the synthesis of inherently chiral para-bromoalkoxycalix[4]arenes based on para-bromination, stepwise regioselective debenzoylation and the following alkylation of the readily available 25-propoxy-26,27-dibenzoyloxycalix[4]arene with propyl bromide or (R)-N-(1-phenylethyl)bromoacetamide has been developed. Three types of the inherently chiral calix[4]arenes in cone or partial cone conformations with asymmetrical (AHHHHBHH, AAHHHBHH, AHBHHCHH) substitution of both upper and lower rims have been obtained in racemic, diastereomerically pure or enantiomerically pure forms. Their structure and the absolute configuration have been determined by NMR and X-ray.