A comparative study of the toxicity of two unsubstituted calixarenes consisting of 4 and 6 phenolic fragments, as well as their p-sulfated derivatives, was carried out on the HT-29 colorectal adenocarcinoma cells cultured in two-dimensional (2D) and three-dimensional (3D) formats. It was shown that both unsubstituted calixarenes decrease the viability of tumor cells; calix[4]arene and calix[6]arene exhibited a cytostatic and a cytotoxic effect, respectively. Sulfated derivatives of calixarenes did not have a pronounced toxic effect on HT-29 cells. However, due to their high hydrophilicity and the ability to form adducts with various therapeutic molecules, they can be used for delivery of anticancer drugs. calixarenes, cytotoxicity, HT-29 cells, 2D cell culture, 3D cell culture The work was financially supported by the Russian Science Foundation (project no. 19-15-00397).

Методом вольтамперометрии на границе раздела двух несмешивающихся растворов электролитов изучен перенос ионов щелочных и щелочноземельных металлов, а также иона аммония, индуцированный каликсаренами 5,11,17,23-тетра(трет-бутил)-26,28-дигидроксикаликс[4]-25,27-краун-5 эфир, 5,11,17,23-тетра(трет-бутил)-26,28-ди(этоксикарбонилметокси)каликс[4]-25,27-краун-5 эфир, 5,11,17,23-тетра(трет-бутил)-25,26,27,28-тетра(этоксикарбонилметокси)-каликс[4]арен. Определены формальные энергии и потенциалы переноса образующихся комплексов, стехиометрия и значения констант устойчивости. На основании данных исследований подобраны оптимальные условия для определения иона аммония методом вольтамперометрии на границе раздела жидкость/жидкость (предел обнаружения составил 3.5 ? 10-6 М). Показана селективность определения иона аммония по отношению к ионам натрия.

The transfer of alkali and alkaline earth metal ions and ammonium ions facilitated by the calixarenes 5,11,17,23-tetra(tert-butyl)-26,28-dihydroxycalix[4]-25,27-crown-5-ether, 5,11,17,23-tetra(tert-butyl)-26,28-di(ethoxycarbonylmethoxy)calix[4]-25,27-crown-5-ether, and 5,11,17,23-tetra(tert-butyl)-25,26,27,28-tetra(ethoxycarbonylmethoxy)-calix[4]arene was studied by voltammetry at the interface between two immiscible electrolyte solutions. The formal energies, transfer potentials, stoichiometry, and stability constants of the complexes were determined. The optimum conditions for determining the ammonium ion by voltammetry at the liquid-liquid interface were selected on the basis of these studies (the detection limit was 3.5 × 10−6 M). The ammonium ion determination showed selectivity relative to the sodium ion.

Asymmetric p-tert-butylcalix[4]-p-R-thiacalix[4]arene tubes (R = tert-Bu, H, 1-adamantyl) were prepared for the first time by reaction of tosyloxyethoxy derivative of p-tert-butylcalix-[4]arene and the corresponding p-R-thiacalix[4]arenas in acetonitrile in the presence of K2CO3. Complex formation of compounds obtained with sodium, potassium, and rubidium iodides in CDCl3-CD3OD, 4:1, was studied by means of 1H NMR. The ionophore properties of the molecule were governed by the character of substituents on the upper rim of the thiacalixarene fragment, and only the molecular tube containing a fragment of the p-(1-adamantyl)-thiacalix[4]arene quantitatively bound potassium ions (quickly) and rubidium ions (slowly).

Procedures have been developed for the preparation of completely and partially adamantylated calix[n]arenes (n = 5, 6) by reaction of 3-R-substituted 1-hydroxyadamantanes (R = H, 4-MeC(6)H(4), 4-MeSO(2)C(6)H(4),4-HO-3-HOCOC(6)H(3), HOCOCH(2)) with p-H-calix[n]arenes (n = 5, 6) and 5,11,23,29-tetra-tert-butylcalix[6]arene in trifluoroacetic acid. Lower- and upper-rim modification of the prepared compounds has been studied. According to the (1)H NMR data, adamantylcalix[6]arenes possessing carboxymethyl groups in the adamantane moieties are characterized by reduced conformational mobility.

Interaction in SrO-CuO-SrF(2) mixtures were studied using X-ray powder diffraction in samples isothermally annealed at 220, 300, and 400 degrees C. The SrCu parallel to O,F system is shown to be a reciprocal ternary system with a stable CuO-SrF(2) diagonal. When in contact with fluorides, HF, or CO(2) at 400 degrees C, Sr(2)CuO(3) and SrCuO(2) cuprates are not stable. New phases including Sr(2)Cu(O,F)(4+delta) with delta = 0 are not found in the system at T <= 400 degrees C. The phase with delta > 0 is obtainable only under oxidative conditions.