Combined antifungal nanocarriers based on self-assembled nystatin and pillar[5]arene with a terpene moiety

In this study, nanocarriers based on self-assembled nystatin and pillar[5]arene were proposed. It was shown that pillar[5]arene with a terpene moiety is capable of targeted delivery of the natural antifungal drug nystatin to the cell membrane of opportunistic fungi (Candida sp.). A water-soluble pillar[5]arene containing a farnesyl moiety was synthesized for the first time. The membranotropic properties of the synthesized pillar[5]arene were demonstrated using the model lipid systems DPPC and DPPC : POPG. The formation of associates between pillar[5]arene and nystatin was confirmed by 2D DOSY, 1H-1H NOESY spectroscopy, and molecular dynamics. UV spectroscopy revealed that pillar[5]arene interacts with nystatin in a 1 : 2 stoichiometry. Dynamic light scattering and transmission electron microscopy showed that pillar[5]arene and nystatin form a stable monodisperse system with spherical-shaped associates. This study revealed that the pillar[5]arene/nystatin system exhibits more effective antifungal activity against clinical isolates of Candida sp. and Saccharomyces cerevisiae compared to free nystatin or pillar[5]arene. These findings represent a promising approach for the discovery of new membrane-targeting nanocarriers for the treatment of fungal diseases.

Weakly bound complexes of 1,2,3-triazole with nitrogen and carbon dioxide isolated in solid argon: A combined FT-IR matrix isolation and theoretical investigation

Matrix isolation FT-IR spectroscopy was combined with quantum-chemical calculations in order to characterize complexes of 1,2,3-triazole (3TR) with nitrogen and carbon dioxide. Geometries of the possible 1:1 and 1:2 complexes, as well as 3TR dimers, were optimized at the DFT (B3LYP-D3) level of theory with the 6-311++G(3df,3pd) basis set. Six different 3TR⋯N2 structures of the 1:1 stoichiometry were optimized which are characterized by weak hydrogen bonds (N-H⋯N and C-H⋯N) and/or Van der Waals type interactions (N⋯C, N⋯N, N⋯π). Two the most stable geometries, both containing a N-H⋯N bridge, were identified experimentally in solid argon. As for 3TR⋯CO2 complexes, out of two minima located on the potential energy surface, only one with a strongly bent N-H⋯O hydrogen bond was detected in the matrix after deposition. In both cases, only annealing experiments at 32 K resulted in the formation of small amounts of 1:2 structures.

Interaction of Phenyl-Substituted Diazaperylenium with Cucurbit[n]uril: Complex versus Supramolecular Polymer

A phenyl-substituted diazaperylenediium dication (DAP) was synthesized that shows concentration-dependent aggregation in water. The host-guest complexation of DAP was studied with the macrocyclic host cucurbit[n]uril (n = 7, 8) in water. With CB[7], it forms a 1:2 complex by placing two aryl substituents inside the CB[7]; whereas, with CB[8], a supramolecular polymer is formed. The resulting complex and supramolecular polymer have been characterized by ITC (isothermal titration calorimetry), ESI-MS (electrospray ionization mass spectrometry), 1H NMR (proton nuclear magnetic resonance), 2D NOESY (two-dimensional nuclear Overhauser enhancement spectroscopy), and DOSY (diffusion-ordered spectroscopy) spectra.

Novel self-adaptive boat-shaped complexes with a tetraphosphine ligand

A series of novel boat-shaped host-guest complexes were designed and synthesized by the combination of a new calixarene fragment-based tetraphosphine ligand L with group 11 metal salts Cu(MeCN)4ClO4 and AgNO3 in a self-assembly process, and by the following anion exchange reactions of complex 1 with sodium p-toluenesulfonate, AcONa, PhCO2Na and sodium 9-anthrylcarboxylate. The host with a novel boat-shaped cavity is capable of self-adaptive encapsulation of various anions of different sizes through M(i)-O coordinations and CHπ interactions between the host and guest anion. The DFT calculations confirmed that the CHπ interaction played a vital role in the self-adaptive phenomenon in complexes 4-6.

Designing tri-branched multiple-site SO2 capture materials

Tri-branched species with multiple isolated reactive sites are proposed for high and uniform SO₂ capture.