An In Vitro Study of the Effect of Viburnum opulus Extracts on Key Processes in the Development of Staphylococcal Infections

Staphylococcus aureus is still one of the leading causes of both hospital- and community-acquired infections. Due to the very high percentage of drug-resistant strains, the participation of drug-tolerant biofilms in pathological changes, and thus the limited number of effective antibiotics, there is an urgent need to search for alternative methods of prevention or treatment for S. aureus infections. In the present study, biochemically characterized (HPLC/UPLC–QTOF–MS) acetonic, ethanolic, and water extracts from fruits and bark of Viburnum opulus L. were tested in vitro as diet additives that potentially prevent staphylococcal infections. The impacts of V. opulus extracts on sortase A (SrtA) activity (Fluorimetric Assay), staphylococcal protein A (SpA) expression (FITC-labelled specific antibodies), the lipid composition of bacterial cell membranes (LC-MS/MS, GC/MS), and biofilm formation (LIVE/DEAD BacLight) were assessed. The cytotoxicity of V. opulus extracts to the human fibroblast line HFF-1 was also tested (MTT reduction). V. opulus extracts strongly inhibited SrtA activity and SpA expression, caused modifications of S. aureus cell membrane, limited biofilm formation by staphylococci, and were non-cytotoxic. Therefore, they have pro-health potential. Nevertheless, their usefulness as diet supplements that are beneficial for the prevention of staphylococcal infections should be confirmed in animal models in the future.     

An expedient synthesis and conformational features of acylhydrazone macrocycles derived from tartaric acid: evidence of water and π aromatic hydrogen bond interactions

Tartaric acid dihydrazides with acetal protected hydroxy groups react with terephthalaldehyde to preferentially form [2+2] bisacylhydrazone macrocycles. The structures of these macrocycles display all anti N–N and CN bonds. Both trans- and cis-C(O)–NH bonds are present in the macrocycle thus allowing the formation of a rather compact macrocyclic structure. The structures of the acylhydrazone macrocycle are shown to be different in the crystal and in the isolated molecule due to the structure determining role of water included in the crystal lattice: in the former all of the OC–C–H bonds are anti, while in the latter both syn- and anti-bonds are present. Both the non-planarity of the bisacylhydrazone molecules and their chiral interchromophoric interactions contribute to the rotatory power of the molecule. The low-temperature X-ray crystal structure of this compound provides direct evidence for hydrogen bonding between water and the aromatic π-electrons in the solid state.     

Temperature and composition dependence of the density and viscosity of binary mixtures of (hyperbranched polymer,B-U3000 + 1-alcohol,or ether)

Density and viscosity were determined for binary mixtures of {hyperbranched polymer, a fatty acid modified dendritic polymer Boltorn U3000 (B-U3000) + 1-alcohol (1-butanol, 1-hexanol, and 1-octanol)} at T = (298.15, 308.15, 318.15, 328.15, and 338.15) K and of {B-U3000 + tert-butyl-methylether (MTBE)} at T = (298.15, 308.15, and 318.15) K and ambient pressure. The temperature dependence of density and viscosity for these systems can be described by linear regression and by the Vogel–Fucher–Tammann equation, respectively. Excess volumes were discussed in a function of mass fractions. Viscosity deviations were calculated and correlated by the Redlich–Kister polynomial expansions using also the mass fractions. The polynomial correlations describe the variation of viscosity with composition. A qualitative discussion on these quantities in terms of molecular interactions is reported.     

Terahertz properties of fluorinated liquid crystals

In this article, optical properties of four fluoro-substituted 4-propyl-4′-[(4-ethylphenyl)ethynyl] biphenyls and liquid crystal mixture A are presented in the terahertz (THz) range. Birefringence, refractive indices and absorption coefficients for ordinary and extraordinary ray of liquid crystals are described in the range of 0.3 to 3.0 THz. It shows that the measured parameters are dependent on the number and placement of fluorine atoms in the molecules. Measurements have been performed using time-pulsed spectroscopy.     

Temperature behavior of the electric field-induced entropy increment within a homologous series of nematogenic compounds

Based on the temperature behavior of the entropy increment induced by the probing electric field in the isotropic phase of mesogenic compounds belonging to the homologous series C(n)H(2n+1)PhCOOPhCN ( n = 4-10), it is found that an ability to the dipolar aggregation of the molecules depends on the alkyl tail length, and, in particular, the ability is strongly reinforced when the number n changes from 7 to 8. The role of the molecular structure in the self-assembling process is discussed.     

Effect of Pseudomonas moorei KB4 Cells’ Immobilisation on Their Degradation Potential and Tolerance towards Paracetamol

Pseudomonas moorei KB4 is capable of degrading paracetamol, but high concentrations of this drug may cause an accumulation of toxic metabolites. It is known that immobilisation can have a protective effect on bacterial cells; therefore, the toxicity and degradation rate of paracetamol by the immobilised strain KB4 were assessed. Strain KB4 was immobilised on a plant sponge. A toxicity assessment was performed by measuring the concentration of ATP using the colony-forming unit (CFU) method. The kinetic parameters of paracetamol degradation were estimated using the Hill equation. Toxicity analysis showed a protective effect of the carrier at low concentrations of paracetamol. Moreover, a pronounced phenomenon of hormesis was observed in the immobilised systems. The obtained kinetic parameters and the course of the kinetic curves clearly indicate a decrease in the degradation activity of cells after their immobilisation. There was a delay in degradation in the systems with free cells without glucose and immobilised cells with glucose. However, it was demonstrated that the immobilised systems can degrade at least ten succeeding cycles of 20 mg/L paracetamol degradation. The obtained results indicate that the immobilised strain may become a useful tool in the process of paracetamol degradation.     

A study of the drying behaviour of various types of hydrated hydroxypropyl cellulose (HPC) and their mixtures with drugs of different solubility using DSC

Journal of Thermal Analysis and Calorimetry - The objective of this research was to interpret the drying behaviour of hydrated hydroxypropyl cellulose (HPC) types HF, MF, LF and their blends (1:1...