In the last 20 years the exploitation of antioxidant activity of selenobased compounds has improved, just due to the use of Ebselen, a selenocompound, as a Glutathione peroxidase (GPx) mimic. However, their clinical use seems to be compromised by the low solubility in water. To deal with this problem, it is possible to take advantage of the new approach including selenosugars in which selenium replaces heterocyclic oxygen. In this frame, to optimize the antioxidant properties of selenosugars, the glycoconjugation with a polyphenolic unit, which is a molecule capable of inhibiting or disabling the action of free radicals, has been considered in this work. The Mitsunobu reaction mechanism links covalently the primary alcoholic function of selenobased glycosyl donors, coming from the commercially available d‐mannose, and phenolic moiety acceptors, to obtain the corresponding glycoconjugates, has been exploited affording the products in efficient yields. A density functional theory (DFT) theoretical study is carried out to help understand the possible influence of the seleno donor on the reactivity. Crucially, a new pathway based on Pummerer‐like rearrangement followed by a glycosylation, gave a selenosugar with selenium in the ring and bearing an acetal‐like functional group at C‐1. All compounds are characterized by nuclear magnetic resonance (NMR) spectroscopy confirming their structures and purity.

Fullerenes functionalized with selenosugar moieties are of particular interest because of their important properties, as one fragment enhances the properties of the other. Selenosugars are not only solubilizing groups, but their intrinsic biological properties also provide additional attractive features to the conjugates. Here the synthesis is reported of a fullerene hexakis‐adduct decorated with 12 peripheral seleno‐ d ‐talitol moieties with a T _h ‐symmetric structure, which can be efficiently synthesized from the hexakis‐adduct of [60]fullerene prepared via a cycloaddition reaction and subsequent copper‐catalyzed azide‐alkyne cycloaddition click chemistry. This large‐scale system, refer to as the selenosugar ball (SeB), has been characterized by ¹ H NMR and ¹³ C NMR spectroscopy, mass spectrometry, UV‐spectroscopy, and dynamic light scattering (DLS). Theoretical calculations using the multilevel DFT‐B3LYP‐D3(BJ)/6–311 G(2 d,p)//PM7 methodology are performed to predict the most stable conformation for the compound and to determine the factors that control the geometry of this molecule. In addition, some physicochemical parameters are estimated. Also, this new compound is tested on human keratinocyte HaCaT cells to determine its cytotoxicity and potential applications.

Iron oxide nanoparticles (IONPs) have high relativity for Magnetic Resonance Imaging (MRI) and have shown a long half-life which can covalently bind with drugs and antibodies that can be used for increased contrast while imaging with MRI. IONPs are approved by the U.S Food and Drug Administration to be used as a contrast agent for MRI in vivo. The Cuban Neuroscience Center has developed a new family of naphthalene derivative compounds called Amylovis^® to be used to diagnose and treatment of Alzheimer’s disease (AD). The goal of this work is to synthesize IONPs with different coatings to be conjugated to Amylovis^® as contrast agents for MRI. Coprecipitation method was employed to obtain the magnetic nuclei, and two synthesis methodologies were performed to coat the IONPs (post-synthesis or in situ). The different coatings used were the following: (3-aminopropyl)triethoxysilane (APTES), dicarboxylic polyethyleneglycol, galic acid, polyacrylic acid and citrate. Carbodiimide method was used as synthetic protocol to conjugate the Amylovis^® moiety to different coatings. The nanoparticles were characterized by DRX, FT-IR, Electrophoretic Light Scattering (ELS) and Dynamic Light Scattering (DLS). Moreover, the stability of nanoparticles in water was evaluated using a sedimentation curve. In order to determine the potential interaction of nanosystems with the beta amyloid peptides, a molecular docking was carried out. The theoretical study showed that coatings do not affect the interaction of Amylovis^® with the receptor, and the new polar groups incorporated increased the affinity to receptor.