Association of Spherical Porous Nanocluster Keplerate-Type Polyoxometalate Mo<Subscript>72</Subscript>Fe<Subscript>30</Subscript> with Biologically Active Substances

The peculiarities of formation of ionic associates of the spherical porous nanocluster polyoxometalate [Mo₇₂Fe₃₀O₂₅₂(CH₃COO)₁₂{Mo₂O₇(H₂O)}₂{H₂Mo₂O₈(H₂O)}(H₂O)₉₁] ~ 150H₂O with biologically active substances, in particular, thiamine chloride using the methods of UV/Vis spectroscopy, pH-metry, laser light scattering (the measurement of Zeta potential and particle size distribution), Raman spectroscopy, infrared spectroscopy and inductively coupled plasma atomic emission spectroscopy has been studied. The location of thiamine molecules on POM’s surface is given. The solubility product of associate was estimated. The formation of molecular associates of polyoxometalate with insulin, albumin has been shown. Using the meglumine acridonacetate the influence of complexing agents on the possibility of obtaining associates on the basis of [Mo₇₂Fe₃₀O₂₅₂(CH₃COO)₁₂{Mo₂O₇(H₂O)}₂{H₂Mo₂O₈(H₂O)}(H₂O)₉₁] ~ 150H₂O has been studied.     

Esters derived from 7-decanoyloxychromone-3-carboxylic acid: synthesis and mesomorphic properties

The synthesis and liquid crystalline properties of a new series of calamitic liquid crystals containing 4-H-benzopyran-4-one (chromone) within the central core is reported. The first homologue in the series display SmA phase (8a), the homologues (8b–e) exhibit SmA and SmC mesophases and the homologues (8f–h) exhibit only a SmC mesophase.     

Enantioselective sensing of dicarboxylates. Influence of the stoichiometry of the complexes on the sensing mechanism

Two new cyclohexane-based thiourea chiral ligands have been synthesized in their enantiomerically pure forms. Both the ability of these ligands in the complexation of chiral dicarboxylates and their sensing properties have been studied. The influence of the stoichiometry of the formed complexes on the fluorescent properties of the systems has been established. The effect of additional substitution in the cyclohexyl moiety was considered by comparing the properties of the newly prepared ligands with those of similar compounds previously described.     

Phosphorus heterocycles from 2‐(2‐hydroxyphenyl)‐1H‐benzimidazole

Sixteen different P(III) and P(V) heterocycles derived from 2‐(2‐hydroxyphenyl)‐1H‐benzimidazole ( 1 ) are reported. In these heterocycles the phosphorus atom is part of a six‐membered unsaturated ring. They were mainly studied by multinuclear NMR. The X‐ray diffraction of 3,4‐ benzimidazole‐5,6‐benzo‐2‐dimethylamino‐2‐seleno‐ 1,3,2‐oxazaphosphorinane is reported. Phosphoranes derived from 1 and 3,5‐di‐tert‐butylcatechol, and bearing Cl, NMe₂, or phenyl as substituent at phosphorus are presented. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:307–320, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20021     

Antibacterial Activity of Chinese Red Propolis against Staphylococcus aureus and MRSA

The antibacterial activity of propolis has long been of great interest, and the chemical composition of propolis is directly dependent on its source. We recently obtained a type of propolis from China with a red color. Firstly, the antibacterial properties of this unusual propolis were determined against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). Studies on its composition identified and quantified 14 main polyphenols of Chinese red propolis extracts (RPE); quantification was carried out using liquid chromatography triple quadrupole tandem mass spectrometry (LC-QQQ-MS/MS) and RPE was found to be rich in pinobanksin, pinobanksin-3-acetate, and chrysin. In vitro investigations of its antibacterial activity revealed that its activity against S. aureus and MRSA is due to disruption of the cell wall and cell membrane, which then inhibits bacterial growth. Despite its similar antibacterial activities against S. aureus and MRSA, metabolomic analysis further revealed the effects of RPE on bacteria metabolism were different. The untargeted metabolomic results showed that a total of 7 metabolites in 12 metabolic pathways had significant changes (Fold change > 2, p < 0.05 *) after RPE treatment in S. aureus, while 11 metabolites in 9 metabolic pathways had significant changes (Fold change > 2, p < 0.05 *) after RPE treated on MRSA. Furthermore, RPE downregulated several specific genes related to bacterial biofilm formation, autolysis, cell wall synthesis, and bacterial virulence in MRSA. In conclusion, the data obtained indicate that RPE may be a promising therapeutic agent against S. aureus and MRSA.     

Correlates with Vaccine Protective Capacity and COVID-19 Disease Symptoms Identified by Serum Proteomics in Vaccinated Individuals

In the last two years, the coronavirus disease 19 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a scientific and social challenge worldwide. Vaccines have been the most effective intervention for reducing virus transmission and disease severity. However, genetic virus variants are still circulating among vaccinated individuals with different disease symptomatology. Understanding the protective- or disease-associated mechanisms in vaccinated individuals is relevant to advances in vaccine development and implementation. To address this objective, serum-protein profiles were characterized by quantitative proteomics and data-analysis algorithms in four cohorts of uninfected and SARS-CoV-2-infected vaccinated individuals with asymptomatic, non-severe, and severe disease symptomatology. The results show that immunoglobulins were the most overrepresented proteins in infected cohorts when compared to PCR-negative individuals. The immunoglobulin profile varied between different infected cohorts and correlated with protective- or disease-associated capacity. Overrepresented immunoglobulins in PCR-positive individuals correlated with protective response against SARS-CoV-2, other viruses, and thrombosis in asymptomatic cases. In non-severe cases, correlates of protection against SARS-CoV-2 and HBV together with risk of myasthenia gravis and allergy and autoantibodies were observed. Patients with severe symptoms presented risk for allergy, chronic idiopathic thrombocytopenic purpura, and autoantibodies. The analysis of underrepresented immunoglobulins in PCR-positive compared to PCR-negative individuals identified vaccine-induced protective epitopes in various coronavirus proteins, including the spike receptor-binding domain RBD. Non-immunoglobulin proteins were associated with COVID-19 symptoms and biological processes. These results evidence host-associated differences in response to vaccination and the possibility of improving vaccine efficacy against SARS-CoV-2.     

Sandwich,Triple-Decker and Other Sandwich-like Complexes of Cyclopentadienyl Anions with Lithium or Sodium Cations

Density functional theory, DFT, calculations were carried out on complexes containing cyclopentadienyl anions and lithium or sodium cations; half-sandwich, sandwich and sandwich-like complexes (among them triple-decker ones) are analyzed. Searches performed through the Cambridge Structural Database revealed that crystal structures containing these motifs exist, mostly structures with sodium cations. The DFT calculations performed here include geometry optimization and frequency calculations of the complexes at the ωB97XD/aug-cc-pVTZ level, followed by the partitioning of the energy of interaction via the Energy Decomposition Analysis scheme, EDA, at the BP86-D3/TZ2P level. Additional calculations and analyses were performed using both the Quantum Theory of Atoms in Molecules, QTAIM, and the Natural Bond Orbital analyses, NBO. The results of this work show that the electrostatic interaction energy is the most important attractive contribution to the total interaction energy of each of the complex systems analyzed here, and that complexation itself leads to minor electron charge shifts.