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Abstract:The handling of metallic nanoparticles often requires their dispersion into several polar and nonpolar solvents. Solid-phase stages or polymer-based ligands are commonly required to complete the transfer. The construction of a thiol ligand based in oleic acid, and its ability to efficiently assist in gold and silver nanoparticle aqueous-organic phase transfer is reported. After the transfer, the particles are completely dispersed in an organic solvent, preserving their diameter and morphology, as confirmed by ultraviolet-visible spectroscopy and scanning transmission electron micrographs.

A series of oxaazacyclophanes and oxaazacalix [4]arene analogues with 18-, 20-and 22-membered rings have been synthesized from diamine and dialdehyde building blocks and structurally characterized by spectroscopic methods. One diamine precursor and four macrocycles have additionally

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Previous studies have reported that different blood groups are associated with the risk of chronic degenerative diseases that mainly involve inflammation and neoplastic processes. We investigate the relationship between blood groups and the erythroprotective effect of extracts from Navicula incerta against oxidative damage as a proposal to develop drugs designed for people with a specific blood type related to chronic pathology. The study was carried out through the elucidation of the erythroprotective potential, anti-inflammatory and antiproliferative activity of Navicula incerta. Research suggests that the presence or absence of certain blood groups increases or decreases the abilities of certain phytochemicals to inhibit oxidative stress, which is related to the systemic inflammatory response involved in the development of different types of cancer. The pigment-rich extracts from Navicula incerta inhibit ROO•- induced oxidative stress in human erythrocytes on the A RhD+ve antigen without compromising the structure of the cell membrane. This result is very important, since the A antigen is related to the susceptibility of contracting prostate cancer. Similarly, it was possible to inhibit the proliferation of cervical (HeLa) and prostate (PC-3) carcinoma. The combinatorial analysis of different biological activities can help design phytochemicals as new candidates for preventive drugs treating the chronic degenerative diseases associated with a specific blood group.

Four novel 27‐ and 29‐membered oxaazacyclophanes were synthetized via the high dilution method in moderate to good yields, employing aromatic dialdehydes and diamines as precursors to generate first the corresponding cyclic Schiff bases, which were then reduced in almost quantitatively yields to the corresponding macrocyclic diamines. All compounds were characterized by conventional techniques such as IR and NMR (1H, 13C) spectroscopy, elemental analysis, and mass spectrometry. Besides, two macrocycles were studied by single‐crystal X‐ray diffraction analysis, which revealed that their cavities are appropriate to include small molecules. Using two representative oxaazacyclophanes (OX‐3 and OX‐4) as wheels and 1,2‐bis(benzimidazolium)ethane salts as axles, [2]pseudorotaxanes were formed in 1:1 (v/v) solvent mixtures of CHCl3 and MeCN and studied by 1H NMR and ultraviolet/visible (UV/Vis) spectroscopy, and electrospray ionization‐time‐of‐flight mass spectrometry, finding in all cases the formation of stable 1:1 complexes. The binding constants of the complexes were determined by UV/Vis and 1H NMR titration experiments, giving values ranging from 0.52 × 103 to 4.6 × 103 M−1. Likely, complex structures were investigated in the gas‐phase using density functional theory calculations at the B3LYP/6‐31G(d) level of theory. The complexation experiments together with the results from the molecular modeling studies indicate that dicationic axles can penetrate the cavity of the oxaazacyclophanes synthesized herein to give a new family of [2]pseudorotaxanes. These supramolecular structures are held together by π−π stacking interactions (charge‐transfer), charge‐assisted hydrogen bonds, and ion dipole forces. Copyright © 2012 John Wiley & Sons, Ltd.