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New amino derivatives of pillar[5]arene were obtained in three stages with good yields. It was shown that pillar[5]arene containing thiaether and tertiary amino groups formed supramolecular complexes with low molecular weight model DNA. Pillar[5]arene formed complexes with a DNA nucleotide pair at a ratio of 1:2 (macrocycle/DNA base pairs), as demonstrated by UV-visible and fluorescence spectroscopy. The association constants of pillar[5]arene with DNA were lgKass1:1 = 2.38 and lgKass1:2 = 5.07, accordingly. By using dynamic light scattering and transmission electron microscopy, it was established that the interaction of pillar[5]arene containing thiaether and tertiary amino groups (concentration of 10−5 M) with a model nucleic acid led to the formation of stable nanosized macrocycle/DNA associates with an average particle size of 220 nm. It was shown that the obtained compounds did not exhibit a pronounced toxicity toward human adenocarcinoma cells (A549) and bovine lung epithelial cells (LECs). The hypothesis about a possible usage of the synthesized macrocycle for the aggregation of extracellular bacterial DNA in a biofilm matrix was confirmed by the example of St. Aureus. It was found that pillar[5]arene at a concentration of 10−5 M was able to reduce the thickness of the St. Aureus biofilm by 15%. [ABSTRACT FROM AUTHOR]

Polymer self-healing films containing fragments of pillar[5]arene were obtained for the first time using thiol/disulfide redox cross-linking. These films were characterized by thermogravimetric analysis and differential scanning calorimetry, FTIR spectroscopy, and electron microscopy. The films demonstrated the ability to self-heal through the action of atmospheric oxygen. Using UV–vis, 2D 1H-1H NOESY, and DOSY NMR spectroscopy, the pillar[5]arene was shown to form complexes with the antimicrobial drug moxifloxacin in a 2:1 composition (logK11 = 2.14 and logK12 = 6.20). Films containing moxifloxacin effectively reduced Staphylococcus aureus and Klebsiella pneumoniae biofilms formation on adhesive surfaces. [ABSTRACT FROM AUTHOR]

In recent years, meroterpenoids have found wide biomedical application due to their synthetic availability, low toxicity, and biocompatibility. However, these compounds are not used in targeted drug delivery systems due to their high affinity for cell membranes, both healthy and in cancer cells. Using the approach of creating supramolecular amphiphiles, we have developed self-assembling systems based on water-soluble pillar[5]arene and synthetic meroterpenoids containing geraniol, myrtenol, farnesol, and phytol fragments. The resulting systems can be used as universal drug delivery systems. It was shown by turbidimetry that the obtained pillar[5]arene/synthetic meroterpenoid systems do not interact with the model cell membrane at pH = 7.4, but the associates are destroyed at pH = 4.1. In this case, the synthetic meroterpenoid is incorporated into the lipid bilayer of the model membrane. The characteristics of supramolecular self-assembly, association constants and stoichiometry of the most stable pillar[5]arene/synthetic meroterpenoid complexes were established by UV-vis spectroscopy and dynamic light scattering (DLS). It was shown that supramolecular amphiphiles based on pillar[5]arene/synthetic meroterpenoid systems form monodisperse associates in a wide range of concentrations. The inclusion of the antitumor drug 5-fluoro-2′-deoxyuridine (floxuridine) into the structure of the supramolecular associate was demonstrated by DLS, 19F, 2D DOSY NMR spectroscopy. [ABSTRACT FROM AUTHOR]

In this work, we have proposed a novel universal stimulus-sensitive nanosized polymer system based on decasubstituted macrocyclic structures—pillar[5]arenes and tetrazole-containing polymers. Decasubstituted pillar[5]arenes containing a large, good leaving tosylate, and phthalimide groups were first synthesized and characterized. Pillar[5]arenes containing primary and tertiary amino groups, capable of interacting with tetrazole-containing polymers, were obtained with high yield by removing the tosylate and phthalimide protection. According to the fluorescence spectroscopy data, a dramatic fluorescence enhancement in the pillar[5]arene/fluorescein/polymer system was observed with decreasing pH from neutral (pH = 7) to acidic (pH = 5). This indicates the destruction of associates and the release of the dye at a pH close to 5. The presented results open a broad range of opportunities for the development of new universal stimulus-sensitive drug delivery systems containing macrocycles and nontoxic tetrazole-based polymers. [ABSTRACT FROM AUTHOR]

Synthetic organic 2D materials are attracting careful attention of researchers due to their excellent functionality in various applications, including storage batteries, catalysis, thermoelectricity, advanced electronics, superconductors, optoelectronics, etc. In this work, thiacalix[4]arene derivatives functionalized by geranyl fragments at the lower rim in cone and 1,3-alternate conformations, that are capable of controlled self-assembly in a 2D nanostructures were synthesized. X-ray diffraction analysis showed the formation of 2D monomolecular-layer nanosheets from synthesized thiacalix[4]arenes, the distance between which depends on the stereoisomer used. It was established by DSC, FSC, and PXRD methods that the obtained macrocycles are capable of forming different crystalline polymorphs, moreover dimethyl sulphoxide (DMSO) is contributing to the formation of a more stable polymorph for cone stereoisomer. The obtained crystalline 2D materials based on synthesized thiacalix[4]arenes can find application in material science and medicine for the development of modern pharmaceuticals and new generation materials. [ABSTRACT FROM AUTHOR]

In the last decade, the chemistry of meroterpenoids—conjugated molecules formed from isoprenyl fragments through biosynthetic pathways—has developed rapidly. The class includes some natural metabolites and fully synthetic fragments formed through nonbiological synthesis. In the field of synthetic receptors, a range of structures can be achieved by combining fragments of different classes of organic compounds into one hybrid macrocyclic platform which retains the properties of these fragments. This review discusses the successes in the synthesis and practical application of both natural and synthetic macrocycles. Among the natural macrocyclic meroterpenoids, special attention is paid to isoprenylated flavonoids and phenols, isoprenoid lipids, prenylated amino acids and alkaloids, and isoprenylpolyketides. Among the synthetic macrocyclic meroterpenoids obtained by combining the "classical" macrocyclic platforms, those based on cyclodextrins, together with meta- and paracyclophanes incorporating terpenoid fragments, and meroterpenoids obtained by macrocyclization of several terpene derivatives are considered. In addition, issues related to biomedical activity, processes of self-association and aggregation, and the formation of host–guest complexes of various classes of macrocyclic merotenoids are discussed in detail. [ABSTRACT FROM AUTHOR]

Calixarenes and related macrocycles have been shown to have antimicrobial effects since the 1950s. This review highlights the antimicrobial properties of almost 200 calixarenes, resorcinarenes, and pillararenes acting as prodrugs, drug delivery agents, and inhibitors of biofilm formation. A particularly important development in recent years has been the use of macrocycles with substituents terminating in sugars as biofilm inhibitors through their interactions with lectins. Although many examples exist where calixarenes encapsulate, or incorporate, antimicrobial drugs, one of the main factors to emerge is the ability of functionalized macrocycles to engage in multivalent interactions with proteins, and thus inhibit cellular aggregation. [ABSTRACT FROM AUTHOR]

Controlling the self-assembly of polyfunctional compounds in interpolyelectrolyte aggregates is an extremely challenging task. The use of macrocyclic compounds offers new opportunities in design of a new generation of mixed nanoparticles. This approach allows creating aggregates with multivalent molecular recognition, improved binding efficiency and selectivity. In this paper, we reported a straightforward approach to the synthesis of interpolyelectrolytes by co-assembling of the thiacalix[4]arene with four negatively charged functional groups on the one side of macrocycle, and pillar[5]arene with 10 ammonium groups located on both sides. Nanostructured polyelectrolyte complexes show effective packaging of high-molecular DNA from calf thymus. The interaction of co-interpolyelectrolytes with the DNA is completely different from the interaction of the pillar[5]arene with the DNA. Two different complexes with DNA, i.e., micelleplex- and polyplex-type, were formed. The DNA in both cases preserved its secondary structure in native B form without distorting helicity. The presented approach provides important advantage for the design of effective biomolecular gene delivery systems. [ABSTRACT FROM AUTHOR]