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.     

Polysiloxane microspheres functionalized with imidazole groups as a palladium catalyst support

Polysiloxane microspheres containing a large number of silanol groups were obtained by an emulsion process of modified polyhydromethylsiloxane. N‐substituted imidazole groups were grafted on these microspheres by the silylation of their silanol groups with N‐[γ‐(dimethylchlorosilyl)propyl]imidazole hydrochloride. The progress of the reaction was monitored using ²⁹Si and ¹³C magic angle spinning (MAS) NMR and its impact on microsphere morphology was studied using scanning electron microscopy (SEM). The usefulness of the imidazole‐functionalized microspheres as a support for a metal catalyst was demonstrated by their reaction with PdCl₂(PhCN)₂. In this way a new heterogenized catalyst, Pd(II) complex with imidazole ligands supported on polysiloxane microspheres, was generated. This catalyst, MPd , was characterized using ¹³C and ²⁹Si MAS NMR, X‐ray photoelectron, Fourier transform infrared and far‐infrared spectroscopies, X‐ray diffraction, SEM–energy‐dispersive X‐ray spectroscopy and wide‐angle X‐ray scattering. The catalyst appears in two structures, as Pd(II) complex and Pd(0) nanoclusters. Its catalytic activity was tested using a model reaction, the hydrogenation of cinnamaldehyde, and compared with that of an analogous complex operating in a homogeneous system. MPd showed a high activity in the promotion of hydrogenation of cinnamaldehyde. The activity in the substrate conversion was stable at least in five cycles of this reaction. The main product was hydrocinnamaldehyde which could be obtained with a yield above 70%. A mechanism of the reaction is proposed. Copyright © 2016 John Wiley & Sons, Ltd.     

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.     

Synthesis and antibacterial activity of some novel N2‐hydroxymethyl and N2‐aminomethyl derivatives of 4‐aryl‐5‐(3‐chlorophenyl)‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐thione

In this investigation, several novel N2‐hydroxymethyl and N2‐aminomethyl derivatives of 5‐(3‐chlorophenyl)‐4‐(4‐methylphenyl)‐2,4‐dihydro‐ 3H‐1,2,4‐triazole‐3‐thione and 4‐(4‐bromophenyl)‐ 5‐(3‐chlorophenyl)‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐ thione were prepared. All synthesized compounds were screened for their antibacterial activity against six Gram‐positive and four Gram‐negative bacterial strains. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:737–743, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20737     

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.     

Properties of η-pentamethylcyclopentadienyl rhodium(III) and iridium(III) complexes with quinolin-8-ol and their cytostatic activity

Reaction of dimers [M(η⁵-C₅Me₅)Cl₂]₂ (M-Rh, Ir) with quinolin-8-ol in molar ratio 1:2 leads to formation of monomer complexes [Rh(η⁵-C₅Me₅)Cl(qol)] (1) and [Ir(η⁵-C₅Me₅)Cl(qol)] (2) (qol = quinolin-8-olate). Compounds 1 and 2 have been characterized with elemental analysis and spectroscopic methods. ¹H NMR spectra revealed that quinolin-8-olate is coordinated via oxygen and nitrogen atoms. The ¹H NMR and ¹³C NMR spectra showed that carbon and hydrogen atoms of pentamethylcyclopentadienyl ligand are equivalent. The structure of rhodium complex has been calculated using DFT B3LYP method. The calculated geometry of complex 1 agrees very well with data found for rhodium complexes containing Cl, C₅Me₅ and qol ligands. Both complexes are active antitumor and antibacterial agents.     

Phase equilibria study of {N-butylquinolinium bis{(trifluoromethyl)sulfonyl}imide + aromatic hydrocarbons,or an alcohol} binary systems

Quinolinium ionic liquid has been prepared from 1-butylquinolinium bromide as a substrate. The work includes specific basic characterization of synthesized compound by NMR spectra, elementary analysis and water content. The basic thermal properties of the pure IL, i.e. melting and glass-transition temperatures, as well as the enthalpy of fusion have been measured using a differential scanning microcalorimetry technique (DSC). (Solid + liquid) phase equilibria (SLE) and (liquid + liquid) phase equilibria (LLE) for the binary systems: ionic liquid (IL) N-butylquinolinium bis{(trifluoromethyl)sulfonyl}imide, {([BQuin][NTf₂]) + aromatic hydrocarbon (benzene, or toluene, or methylbenzene, or propylbenzene, or thiophene), or an alcohol (ethanol, or 1-butanol, or 1-hexanol, or 1-octanol, or 1-dodecanol)} have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from (260 to 330) K. For the binary systems, the simple eutectic diagrams were observed with immiscibility in the liquid phase with an upper critical solution temperature (UCST). For mixtures with alcohols, it was observed that with increasing chain length of an alcohol the solubility decreases and the UCST increases. In the case of mixture (IL + benzene, or alkylbenzene, or thiophene) the eutectic systems with mutual immiscibility in the liquid phase with very high UCSTs were observed. These points were not detectable with our method and they were observed at low ionic liquid mole fraction. Densities at high temperatures were determined and extrapolated to T = 298.15 K. Well-known UNIQUAC, and NRTL equations have been used to correlate experimental SLE data sets. For the systems containing immiscibility gaps {IL + an alcohol} parameters of the LLE correlation equation have been derived using only the NRTL equation.     

On Families of Graphs of Large Cycle Indicator, Matrices of Large Order and Key Exchange Protocols With Nonlinear Polynomial Maps of Small Degree

This paper studies the group theoretical protocol of Diffie?CHellman key exchange in the case of symmetrical group ${S_{p^n}}$ and more general Cremona group ${C(\mathbb K^n)}$ of polynomial automorphisms of free module ${\mathbb K^n}$ over arbitrary commutative ring ${\mathbb K}$ . This algorithm depends very much on the choice of the base ${g_n \in C( \mathbb K^n)}$ . It is important to work with the base ${g_n \in C( \mathbb K^n)}$ , which is a polynomial map of a small degree and a large order such that the degrees of all powers ${g_n^k}$ are also bounded by a small constant. We suggest fast algorithms for generation of a map ${g_n={f_n} \xi_nf_n^{-1}}$ , where ?? _n is an affine transformation (degree is 1) of a large order and f _n is a fixed nonlinear polynomial map in n variables such that ${f_n^{-1}}$ is also a polynomial map and both maps f _n and ${f_n^{-1}}$ are of small degrees. The method is based on properties of infinite families of graphs with a large cycle indicator and families of graphs of a large girth in particular. It guaranties that the order of g _n is tending to infinity as the dimension n tends to infinity. We propose methods of fast generation of special families of cubical maps f _n such that ${f_n^{-1}}$ is also of degree 3 based on properties of families of graphs of a large girth and graphs with a large cycle indicator. At the end we discuss cryptographical applications of maps of the kind ?? f _n ??^?1 and some graph theoretical problems motivated by such applications.