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Squalene-based adjuvant compositions that can provide effective induction of specific humoral immune response have been developed. Recombinant receptor-binding domain (RBD) of surface S-protein of SARS-CoV-2 was used to evaluate the properties of the composition. Immunization of mice with the developed squalene-based compositions in combination with RBD allows obtaining high titers of specific antibodies: from 10 5 to 2×10 6 . The blood sera from immunized mice exhibit neutralizing activity against SARS-CoV-2 Delta variant (B.1.617.2) with a titer up to 1:2000., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

In the present study, the synthesis of oxygen-containing quaternary phosphonium salts (oxy-QPSs) was described. Within this work, structure-property relationships of oxy-QPSs were estimated by systematic analysis of physical-chemical properties. The influence of the oxygen-containing substituent was examined by comparing the properties of oxy-QPSs in homology series as well as with phosphonium analog-included alkyl side chains. The crystal structure analysis showed that the oxygen introduction influences the conformation of the side chain of the oxy-QPS. It was found that oxy-QPSs, using an aprotic co-solvent, dimethylsulfoxide (DMSO), can dissolve microcrystalline cellulose. The cellulose dissolution in oxy-QPSs appeared to be dependent on the functional group in the cation and anion nature. For the selected conditions, dissolution of up to 5 wt% of cellulose was observed. The antimicrobial activity of oxy-QPSs under study was expected to be low. The biocompatibility of oxy-QPSs with fermentative microbes was tested on non-pathogenic Saccharomyces cerevisiae , Lactobacillus plantarum , and Bacillus subtilis . This reliably allows one to safely address the combined biomass destruction and enzyme hydrolysis processes in one pot.

Herein, the synthesis of ferrocene-containing salts is presented. Acylation of ferrocene (Fc) according to the Friedel-Crafts method led to ω-bromoacyl ferrocenes. The ω-bromoacyl ferrocenes were subsequently introduced to quaternization reaction with tri- tert -butyl phosphine, which resulted in phosphonium salts. Obtained phosphonium salts were characterized by physical methods. The electrochemical properties of phosphonium salts were studied by cyclic voltammetry (CV). It was found that the replacement of n -butyl fragments at the phosphorus atom by tert -butyl leads to a more anodic potential shift. In contrast to isolobal structures Fc-C(O)(CH 2 ) n P + ( n -Bu) 3 X - and Fc-(CH 2 ) n+1 P + ( n -Bu) 3 X - , the CV curves of Fc-C(O)(CH 2 ) n P + ( t -Bu) 3 X - and Fc-(CH 2 ) n+1 P + ( t -Bu) 3 X - did not show a large discrepancy between forward and reverse currents. The transformation of the C=O groups to CH 2 fragments had a significant effect on the electrochemical properties of ferrocene salts, the oxidation potential of which is close to that of pure ferrocene.

Structure-activity relationships are important for the design of biocides and sanitizers. During the spread of resistant strains of pathogenic microbes, insights into the correlation between structure and activity become especially significant. The most commonly used biocides are nitrogen-containing compounds; the phosphorus-containing ones have been studied to a lesser extent. In the present study, a broad range of sterically hindered quaternary phosphonium salts (QPSs) based on tri- tert -butylphosphine was tested for their activity against Gram-positive ( Staphylococcus aureus, Bacillus cereus , Enterococcus faecalis ) and Gram-negative ( Escherichia coli , Pseudomonas aeruginosa ) bacteria and fungi ( Candida albicans , Trichophyton mentagrophytes var. gypseum). The cation structure was confirmed to determine their biological activity. A number of QPSs not only exhibit high activity against both Gram-positive and -negative bacteria but also possess antifungal properties. Additionally, the hemolytic and cytotoxic properties of QPSs were determined using blood and a normal liver cell line, respectively. The results show that tri- tert -butyl( n -dodecyl)phosphonium and tri- tert -butyl( n -tridecyl)phosphonium bromides exhibit both low cytotoxicity against normal human cells and high antimicrobial activity against bacteria, including methicillin-resistant strains S. aureus ( MRSA ). The mechanism of QPS action on microbes is discussed. Due to their high selectivity for pathogens, sterically hindered QPSs could serve as effective tunable biocides.

A new family of sterically hindered alkyl(tri- tert -butyl) phosphonium salts ( n -C n H 2n+1 with n = 2, 4, 6, 8, 10, 12, 14, 16, 18, 20) was synthesized and evaluated as stabilizers for the formation of palladium nanoparticles (PdNPs), and the prepared PdNPs, stabilized by a series of phosphonium salts, were applied as catalysts of the Suzuki cross-coupling reaction. All investigated phosphonium salts were found to be excellent stabilizers of metal nanoparticles of small catalytically active size with a narrow size distribution. In addition, palladium nanoparticles exhibited exceptional stability: the presence of phosphonium salts prevented agglomeration and precipitation during the catalytic reaction.

Analysis of infrared spectra of palladium nanoparticles (NPs) immersed in the tri-tert-butyl-R-phosphonium-based ionic liquids (ILs) demonstrates that both cations and anions of the ILs interact with the NPs. According to quantum-chemical simulations of these interactions, the binding energy of anions to the Pd6 cluster, taken as a minimal-size model of the NPs, increases from ∼6 to ∼27 kcal mol(-1) in the order [PF6](-)≈ [BF4](-) < [Tf2N](-) < [OTf](-) < [Br](-)≪ [TFA](-). In contrast, the binding energy for all types of the [Bu(t)3PR](+) cations slightly varies at about ∼22 kcal mol(-1) only moderately depending on the choice of the R moiety (n-pentyl, 2-hydroxyethyl, 2-methoxyethyl, 2-ethoxy-2-oxoethyl). As a result, the energies of interaction between a Pd6 cluster and various ion pairs, formed by the abovementioned counter-ions, follow the order found for the anions and vary from ∼24 to ∼47 kcal mol(-1). These values are smaller than the energy of addition of a Pd atom to a Pdn cluster (∼58 kcal mol(-1)), which suggests kinetic stabilization of the NPs in phosphonium-based ILs rather than thermodynamic stabilization. The results are qualitatively similar to the trends found earlier for interactions between palladium clusters and components of imidazolium-based ILs, in spite of much larger contributions of the London dispersion forces to the binding of the [Bu(t)3PR](+) cations to the cluster (up to 80%) relative to the case of 1-R-3-methylimidazolium cations (up to 40%).

Traumatic brain injury among other injuries of human body reaches up to 30-50% and, according to the WHO, it grows by 2%. Severe traumatic brain injury (such as severe brain contusion, epidural, subdural and intracerebral hematoma, intracerebral hygroma, diffuse axonal injury) in the structure of general trauma amounts 4-20%. The prognosis of traumatic brain injury mainly depends on the timeliness of the first aid. The therapeutic measures usually begin at the place of the accident or in the ambulance vehicle (hence the clear role of the specialist team). It is advised for children with severe traumatic brain injury to be directed to specialized neurosurgical or trauma hospitals, where it is possible to provide them with adequate medical care. This work is dedicated to the enhancement of the intensive care quality during severe traumatic brain injury in children of Chuvash Republic, by the means of integrated patient assessment.