Microorganisms Resistant to White Phosphorus

We present preliminary results on the successful culturing of different microbial taxonomic groups on media containing white phosphorus (P4) as the sole source of phosphorus. The increase in culture resistance resulting from targeted selection was demonstrated. The highest concentration of P4 used in the study exceeds the threshold limit concentration of P4 in wastewater mud by 5000 times. Putative metabolites of P4 were also investigated. Keywords: biodegradation; white phosphorus; Aspergillus niger; Streptomyces sp. A

Antitumor activity of lower rim amino derivatives of thiacalixarene

© 2020 Author(s). Dependence of cytotoxicity of lower-rim substituted aminoalkoxythiacalix[4]arenes towards normal and tumor cell lines on the distance from receptor amino group to the macrocyclic scaffold, as well as the oxidation state of nitrogen atom has been determined

The construction of supramolecular and hybrid Ag-AgCl nanoparticles with photodynamic therapy action on the base of tetraundecylсalix[4]resorcinarene-mPEG conjugate

The development of new nanomaterials with therapeutic potential is a modern task due to their outstanding properties and promising effectiveness. Here the usage of acylhydrazone bond-based сalix[4]resorcinarene-mPEG conjugate (C11-mPEG) in the formation of both supramolecular and hybrid nanoparticles with in vitro photodynamic therapy (PDT) activity is described. C11-mPEG is hydrolyzed with a decrease in pH of solution; the conjugate and its degradation product have the low hemolytic activity and low cytotoxicity against normal cells. The self-association of the conjugate was studied in the aqueous solutions with pH 7.4 and 5. C11-mPEG forms self-associates that serve as pH-sensitive supramolecular nanocontainers for photosensitizer Methylene Blue (MB). In the in vitro PDT experiment the stronger decrease of tumor cells (M-Hela cells) viability in the presence of encapsulated MB is observed in comparison with free MB. Also C11-mPEG acts as a stabilizing agent for Ag@AgCl nanoparticles, which were obtained with 5/1 and 2/1 Ag+/C11-mPEG molar ratio and different reducing agents (sodium borohydride and hydrazine hydrate). The stronger cytotoxicity of hybrid NPs against tumor cells in comparison with normal was shown. Further it was found that the irradiation of the hybrid nanoparticles at 630 nm leads to the sharp increase in their cytotoxicity against M-Hela cells. The high level of ROS formation in the cells in the presence of both supramolecular and hybrid NPs under in vitro PDT experiment was determined

Doxorubicin delivery by polymer nanocarrier based on N-methylglucamine resorcinarene

© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. Herein we describe a simple method for the synthesis of polymer nanocarrier for the doxorubicin delivery. The nanocarrier consists of N-methyl-glucamine resorcinarenes that are covalently bound to phenylboronic acid. The nanocarrier is stable at normal pH but is hydrolysed at pH below 6. It demonstrates low cytotoxicity and haemolytic activity. Doxorubicin was successfully loaded into the nanocarriers cavity and its release occurs at pH. Flow cytometry data showed that the carrier improves the penetration of doxorubicin into M-Hela cancer cell lines. The encapsulated doxorubicin demonstrates higher cytotoxicity towards the cancer cells

A novel salt-responsive hydrogel on the base of calixresorcinarene–mPEG amide conjugate

A novel low toxic amide calix[4]resorcinarene–mPEG conjugates of amphiphilic and dendrimeric character were synthesized. It was shown that the growth of the temperature or the ionic strength growth of the solution leads to different demonstration of the amplification of hydrophobic interactions in the conjugates self-associates. It was found that in PBS or 0.9 % NaCl solutions the amphiphilic conjugate form micellar solution, and the dendrimeric conjugate – hydrogel, which is capable of the reversible sol-gel transition. It was shown by DSC analysis that the dendrimeric conjugate binds of 15 % of water molecules in an aqueous solution (non-freezing bound water), but in the salt solution the conjugate-water interaction is practically absent. This leads to the additional self-aggregation of conjugate molecules and to the gel formation. The high degree of substrate sorption by the hydrogel (Methylene Blue, encapsulation effectiveness is 78 %) and its reversible binding-release by the regulation of the solution ionic strength have been demonstrated

Design and synthesis of amphiphilic 2-hydroxybenzylphosphonium salts with antimicrobial and antitumor dual action

© 2020 Elsevier Ltd Here we report the synthesis and biological evaluation of a series of new 2-hydroxybenzylphosphonium salts (QPS) with antimicrobial and antitumor dual action. The most active compounds exhibit antimicrobial activity at a micromolar level against Gram-positive bacteria Sa (ATCC 209p and clinical isolates), Bc (1–2 μM) and fungi Tm and Ca, and induced no notable hemolysis at MIC. The change in nature of substituents of the same length led to a drastic change of biological activity. Self-assembly behavior of the octadecyl and oleyl derivatives was studied. QPS demonstrated self-assembly within the micromolar range with the formation of nanosized aggregates capable of the solubilizing hydrophobic probe. The synthesized phosphonium salts were tested for cytotoxicity. The most potent salt was active against on M−Hela cell line with IC50 on the level of doxorubicin and good selectivity. According to the cytofluorimetry analysis, the salts induced mitochondria-dependent apoptosis

Ammonium-Charged Sterically Hindered Phenols with Antioxidant and Selective Anti-Gram-Positive Bacterial Activity

© 2020 Wiley-VHCA AG, Zurich, Switzerland The increase in the resistance of pathogens, in particular Staphylococcus aureus, to the action of antibiotics necessitates the search for new readily available and non-toxic drugs. In solving this problem, phenolic acylhydrazones have high potential. In this communication, the synthesis of quaternary ammonium compounds containing a differently substituted phenolic moiety has been performed. An initial study of antimicrobial activity showed that these compounds are highly selective against S. aureus and B. cereus. The highest activity (MIC 2.0 μm) was shown by hydrazones containing a catechol fragment. These compounds are more than 3-fold more active against S. aureus and 3–10-fold more active against B. cereus than norfloxacin. Low hemolytic and high antioxidant activities of all new compounds were also established

Modulation of aggregation behavior, antimicrobial properties and catalytic activity of piperidinium surfactants by modifying their head group with a polar fragment

To establish the effect of surfactants structure on their functional activity a number of alkyl-N-hydroxyethylpiperidinium bromides with different length of the hydrophobic tail were synthesized and characterized. Aggregation parameters of these surfactants were determined using tensiometry and fluorimetry. It was shown that the piperidinium surfactants, including those functionalized with OH groups, show a high antimicrobial effect at concentrations lower than critical micelle concentration for both bacteria and fungi, with the low hemolytic activity revealed. In addition, these surfactants were studied as micellar catalysts in alkaline hydrolysis of carboxylic acid esters. Micellar catalytic effect increases with an growth in the length of the alkyl tail, as well as with an increase in the number of hydroxy groups in surfactant molecule and can exceed two orders of magnitude

The highly regioselective synthesis of novel imidazolidin-2-ones via the intramolecular cyclization/electrophilic substitution of urea derivatives and the evaluation of their anticancer activity

A series of novel 4-(het)arylimidazoldin-2-ones were obtained by the acid-catalyzed reaction of (2,2-diethoxyethyl)ureas with aromatic and heterocyclic C-nucleophiles. The proposed approach to substituted imidazolidinones benefits from excellent regioselectivity, readily available starting materials and a simple procedure. The regioselectivity of the reaction was rationalized by quantum chemistry calculations and control experiments. The anti-cancer activity of the obtained compounds was tested in vitro

Polymer–colloid complexes based on cationic imidazolium amphiphile, polyacrylic acid and dna decamer

The solution behavior and physicochemical characteristics of polymer–colloid complexes based on cationic imidazolium amphiphile with a dodecyl tail (IA-12) and polyacrylic acid (PAA) or DNA decamer (oligonucleotide) were evaluated using tensiometry, conductometry, dynamic and electrophoretic light scattering and fluorescent spectroscopy and microscopy. It has been established that PAA addition to the surfactant system resulted in a ca. 200-fold decrease in the aggregation threshold of IA-12, with the hydrodynamic diameter of complexes ranging within 100–150 nm. Electrostatic forces are assumed to be the main driving force in the formation of IA-12/PAA complexes. Factors influencing the efficacy of the complexation of IA-12 with oligonucleotide were determined. The nonconventional mode of binding with the involvement of hydrophobic interactions and the intercalation mechanism is probably responsible for the IA-12/oligonucleotide complexation, and a minor contribution of electrostatic forces occurred. The latter was supported by zeta potential measurements and the gel electrophoresis technique, which demonstrated the low degree of charge neutralization of the complexes. Importantly, cellular uptake of the IA-12/oligonucleotide complex was confirmed by fluorescence microscopy and flow cytometry data on the example of M-HeLa cells. While single IA-12 samples exhibit roughly similar cytotoxicity, IA-12–oligonucleotide complexes show a selective effect toward M-HeLa cells (IC50 1.1 µM) compared to Chang liver cells (IC50 23.1 µM)