Tris(2-Pyridylmethylamine)V(O)2 Complexes as Counter Ions of Diprotonated Decavanadate Anion: Potential Antineoplastic Activity

Projects funded this research: 100517029-VIEP2021 and 100233622-VIEP2021, and the PRODEP Academic Group BUAP-CA-263 (SEP, Mexico). Financial support was also provided by Junta de Andalusia (Spain), Project number FQM-394. NC, BM-V, and LN wish to thank CONACyT (Mexico) Ph.D. fellowship support numbers 390894, 593307, and 697889.The synthesis and theoretical-experimental characterization of a novel diprotanated decavanadate is presented here due to our search for novel anticancer metallodrugs. Tris(2-pyridylmethyl)amine (TPMA), which is also known to have anticancer activity in osteosarcoma cell lines, was introduced as a possible cationic species that could act as a counterpart for the decavanadate anion. However, the isolated compound contains the previously reported vanadium (V) dioxido-tpma moieties, and the decavanadate anion appears to be diprotonated. The structural characterization of the compound was performed by infrared spectroscopy and single-crystal X-ray diffraction. In addition, DFT calculations were used to analyze the reactive sites involved in the donoracceptor interactions from the molecular electrostatic potential maps. The level of theory mPW1PW91/6–31G(d)-LANL2DZ and ECP = LANL2DZ for the V atom was used. These insights about the compounds’ main interactions were supported by analyzing the noncovalent interactions utilizing the AIM and Hirshfeld surfaces approach. Molecular docking studies with small RNA fragments were used to assess the hypothesis that decavanadate’s anticancer activity could be attributed to its interaction with lncRNA molecules. Thus, a combination of three potentially beneficial components could be evaluated in various cancer cell lines.European CommissionPRODEP Academic Group (SEP, Mexico) BUAP-CA-263Junta de Andalusia (Spain) FQM-394Consejo Nacional de Ciencia y Tecnologia (CONACyT) 390894 593307 697889 SEP PRODEP BUAP-PTC_61

Cysteine-based 3-substituted 1, 5-benzoxathiepin derivatives: Two new classes of anti-proliferative agents

Two distinct series of the 3-amino-1, 5-benzoxathiepin scaffold, derived from L-cysteine, were synthesized and evaluated for their anti-proliferative activity in the breast cancer MDA-MB-231 and MCF-7 cells, and in the ovarian carcinoma SKOV-3 cell line. (3R)-Amino-3, 4-dihydro-2H-1, 5-benzoxathiepin [(R)-10] was diversified into two forms: (a) by incorporating different amino acids at its position 3, through an amide bond; and (b) by construction of the purine ring to give 6-chloro-9-[2-(3, 4-dihydro-2H-1, 5-benzoxathiepin-(3R)-yl)]-9H-purine [(R)-28]. Nevertheless, when the introduction of iodine was tried at position 2 of the purine ring of (R)-28, 2-{[2-(6-chloro-2-iodo-9H-purin-9-yl) prop-2-en-1-yl] thio} phenol (34) was obtained. Compound 34 shows activity against cancer cells. Interestingly, 34 inhibits mammosphere formation at the micromolar range, demonstrating activity against cancer stem cells. Although further studies of its targets and mechanism of action are needed, these findings support the therapeutic potential of this compound in cancer

Proton conductivity and luminiscence properties of lanthanide aminotriphosphonates

Metal phosphonates are multifunctional solids with tunable properties, such as internal H-bond networks, and high chemical and thermal stability [1]. In the present work, we describe the synthesis, structural characterization, luminescent properties and proton conduction performance of a new family of isostructural cationic compounds with general formula [Ln(H4NMP)(H2O)2]Cl·2H2O [Ln = La3+, Pr3+, Sm3+, Gd3+, Tb3+, Dy3+, Ho3+, H6NMP = nitrilotris(methylphosphonic acid)]. These solids are formed by positively charge layers, which consist of isolated LnO8 polyhedra and bridge chelating NMP2- ligands, held apart by chloride ions and water molecules. This arrangement result in extended interlayer hydrogen networks with possible proton transfer pathways. The proton conductivity of Gd3+ sample, selected as prototype of the series, was measured. In the range between range 25º and 80 ºC, the conductivity increase with the temperature up to a maximum value of 3.10-4 S·cm-1, at relative humidity of 95 %. The activation energy obtained from the Arrhenius plot (Figure 1) is in the range corresponding to a Grotthuss transfer mechanism.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. FQM-1656; MAT2013-41836-R

Biomimetic Citrate-Coated Luminescent Apatite Nanoplatforms for Diclofenac Delivery in Inflammatory Environments

Luminescent nanoparticles are innovative tools for medicine, allowing the imaging of cells and tissues, and, at the same time, carrying and releasing different types of molecules. We explored and compared the loading/release ability of diclofenac (COX-2 antagonist), in both undoped-and luminescent Terbium3+ (Tb3+)-doped citrate-coated carbonated apatite nanoparticles at different temperatures (25, 37, 40 °C) and pHs (7.4, 5.2). The cytocompatibility was evaluated on two osteosarcoma cell lines and primary human osteoblasts. Biological effects of diclofenac-loadednanoparticles were monitored in an in vitro osteoblast’s cytokine–induced inflammation model by evaluating COX-2 mRNA expression and production of PGE2. Adsorption isotherms fitted the multilayer Langmuir-Freundlich model. The maximum adsorbed amounts at 37 °C were higher than at 25 °C, and particularly when using the Tb3+-doped particles. Diclofenac-release efficiencies were higher at pH 5.2, a condition simulating a local inflammation. The luminescence properties of diclofenac-loaded Tb3+-doped particles were affected by pH, being the relative luminescence intensity higher at pH 5.2 and the luminescence lifetime higher at pH 7.4, but not influenced either by the temperature or by the diclofenac-loaded amount. Both undoped and Tb3+-doped nanoparticles were cytocompatible. In addition, diclofenac release increased COX-2 expression and decreased PGE2 production in an in vitro inflammation model. These findings evidence the potential of these nanoparticles for osteo-localized delivery of anti-inflammatory drugs and the possibility to localize the inflammation, characterized by a decrease in pH, by changes in luminescence

A New Kind of Quinonic-Antibiotic Useful Against Multidrug-Resistant S. aureus and E. faecium Infections

Indexación: Scopus.A rapid emergence of resistant bacteria is occurring worldwide, endangering the efficacy of antibiotics and reducing the therapeutic arsenal available for treatment of infectious diseases. In the present study, we developed a new class of compounds with antibacterial activity obtained by a simple, two step synthesis and screened the products for in vitro antibacterial activity against ATCC® strains using the broth microdilution method. The compounds exhibited minimum inhibitory concentrations (MIC) of 1⁻32 μg/mL against Gram-positive ATCC® strains. The structure⁻activity relationship indicated that the thiophenol ring is essential for antibacterial activity and the substituents on the thiophenol ring module, for antibacterial activity. The most promising compounds detected by screening were tested against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VREF) clinical isolates. We found remarkable activity against VREF for compounds 7 and 16, were the MIC50/90 were 2/4 µg/mL and 4/4 µg/mL, respectively, while for vancomycin the MIC50/90 was 256/512 µg/mL. Neither compound affected cell viability in any of the mammalian cell lines at any of the concentrations tested. These in vitro data show that compounds 7 and 16 have an interesting potential to be developed as new antibacterial drugs against infections caused by VREF.https://www.mdpi.com/1420-3049/23/7/177

Crystal engineering in confined spaces. A novel method to grow crystalline metal phosphonates in alginate gel systems

In this paper we report a crystal growth method for metal phosphonate frameworks in alginate gels. It consists of a metalcontaining alginate gel, in which a solution of phosphonate ligand is slowly diffused. Crystals of metal phosphonate products are formed inside the gel. We have applied this for a variety of metal ions (alkaline-earth metals, transition metals and lanthanides) and a number of polyphosphonic acid and mixed carboxy/phosphonic acid ligands.Proyecto nacional MAT2010-1517

Imidazole-containing Co2+ and Ni2+ etidronates: crystal structures and electrochemical behaviour

Proyecto Nacional PID2019-110249RB-I00, PAIDI2020 de la Junta de Andalucia, Ayudas del Plan Propio de Investigación de la Universidad de Málaga para la contratación predoctoral (PRE2020-094459).Metal phosphonates-based coordination polymers (CPs) are known to exhibit versatile structural diversity and functionality. Thus, they have been used, among other applications, as electrocatalyst precursors for both, PEMFCs and electrolysers. In this work, we report the synthesis, crystal structure and electrochemical properties of imidazole-containing Co2+, Ni2+ and Zn2+ derivatives of the etidronic acid, (HO)2P(O)-C(CH3)(OH)-P(O)(OH)2 (ETID). Analyses of the crystal structures reveals that these solids are 1D, in which the imidazole molecules form part of the coordination sphere of the cations (Co2+, Ni2+) or act as charge-compensating imidazolium cations (Zn2+). Co2+ and Ni2+ solids were pyrolysed under 5% H2/Ar atmosphere at different temperatures. The resulting metal phosphides were tested as electrocatalysts for the Oxygen Evolution and Reduction Reactions (OER and ORR, respectively) and the Hydrogen Evolution Reaction (HER). Preliminary results indicate that Co2+ derivatives exhibit better performance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Slow-spin relaxation of a low-spin S = 1/2 FeIII carborane complex

In this communication, we report the first evidence of slow-spin relaxation of a low-spin FeIII carborane complex. Iron S=1/2 complexes showing such behaviour are specially appealing as qubits candidates because they fulfil some of the main requirements to reach long decoherence times: moderate magnetic anisotropy, small spin, metal element mainly with zero-nuclear spin and furthermore, large versatility to introduce chemical modifications

Three-Component Copper-Phosphonate-Auxiliary Ligand Systems: Proton Conductors and Efficient Catalysts in Mild Oxidative Functionalization of Cycloalkanes

The synthesis, structural characterization, topological analysis, proton conductivity, and catalytic properties are reported of two Cu(II)-based compounds, namely a dinuclear Cu(II) complex [Cu2(μ-VPA)2(phen)2(H2O)2]· 8H2O (1) (H2VPA = vinylphosphonic acid, phen = 1,10- phenanthroline) and a 1D coordination polymer [Cu(μ- SO4)(phen)(H2O)2]∞ (2). Their structural features and Hbonding interactions were investigated in detail, showing that the metal−organic structures of 1 and 2 are extended by multiple hydrogen bonds to more complex 2D or 1D Hbonded architectures with the kgd [Shubnikov plane net (3.6.3.6)/dual] and SP 1-periodic net (4,4)(0,2) topology, respectively. These nets are primarily driven by the H-bonding interactions involving water ligands and H2O molecules of crystallization; besides, the (H2O)4/(H2O)5 clusters were identified in 1. Both 1 and 2 are moderate proton conductors, with proton conductivity values, σ = 3.65 × 10−6 and 3.94 × 10−6 S·cm−1, respectively (measured at 80 °C and 95% relative humidity). Compounds 1 and 2 are also efficient homogeneous catalysts for the mild oxidative functionalization of C5−C8 cycloalkanes (cyclopentane, cyclohexane, cycloheptane, and cyclooctane), namely for the oxidation by H2O2 to give cyclic alcohols and ketones and the hydrocarboxylation by CO/H2O and S2O82− to the corresponding cycloalkanecarboxylic acids as major products. The catalytic reactions proceed under mild conditions (50−60 °C) in aqueous acetonitrile medium, resulting in up to 34% product yields based on cycloalkane substrate.Proyecto MAT2016-77648-R del MINECO y proyecto FQM-1656 de la Junta de Andalucí

Common Structural Features in Calcium Hydroxyphosphonoacetates. A High-Throughput Screening

R,S-Hydroxyphosphonoacetic acid (H3HPA) is an inexpensive multidentate organic ligand widely used for the preparation of organo-inorganic hybrid materials. There are reports of several crystal structures and the variability of the resulting frameworks is strikingly high, in contrast with the simplicity of the ligand. In an attempt to investigate and rationalize some salient structural features of the crystal structures, we have carried out a systematic high-throughput study of the reaction of H3HPA with Ca2þ in aqueous solutions (pH values ranging 1.0-7.5) at room temperature and hydrothermally at 180 ºC. The tested synthetic conditions yielded five crystalline singlephase Ca-H3HPA hybrids: Ca3(O3PCHOHCOO)2 · 14H2O (1), Ca(HO3PCHOHCOO) · 3H2O (2), Ca5(O3PCHOHCOO)2(HO3PCHOHCOO)2 · 6H2O (3), CaLi(O3PCHOHCOO) (4), and Ca2Na(O3PCHOHCOO (HO3PCHOHCOO) ·1.5H2O(5). Four new crystal structures, 2-5, are reported (three frompowder diffraction data and one from single-crystal data), which allowed us to unravel some key common structural features. The Ca-H3HPA hybrids without an extra alkaline cation, 1-3, contain a common structural motif, which has been identified as a linear Ca-H3HPA-Ca-H3HPA-Ca trimer. This inorganic motif has a central Ca2+ in a distorted octahedral environment, whereas the two side Ca2+ cations are in an eight-coordinated oxygen-rich environment. The H3HPA ligands are chelating the central Ca2+ through two pairs of carboxylate and phosphonate oxygen atoms forming six-membered rings, Ca-O-C-C-P-O-Ca. This coordination mode allows the peripheral Ca(II) ions to bind the ligand through the -OH group and the other carboxylate oxygen, forming a fivemembered ring, Ca-O-C-C-O-Ca. The presence of alkaline cations, Li+ and Na+, disrupt this common structural feature leading to highly dense frameworks. Finally, similarities (and differences) between Ca-H3HPA and Cd-H3HPA hybrids are also discussed.Proyectos nacionales MAT2009-07016 y MAT2010-15175 (MICINN, España