Introduction to Special Issue "The Self-Assembly and Design of Polyfunctional Nanosystems 3.0".

Stimulus-responsive systems allowing for the controlled release of drugs [...

Cyclization of alanyl-valine dipeptides in the solid state. The effects of molecular radiator and heat capacity.

Heating of linear dipeptides above a critical temperature initiates their cyclization even in the solid state. This method of obtaining cyclic dipeptides meets the requirements of "green chemistry", provides a high yield of the main product and releases only water as a by-product of the reaction, and does not require solvents. However, to date, the cyclization of only a small number of dipeptides in the solid state has been studied, and some correlations of the process were discovered.

Comprehensive overview of heat management methods for enhancing photovoltaic thermal systems.

The paper examines strategies to improve the efficiency of photovoltaic (PV) systems, which are challenged by high operating temperatures that reduce performance. It focuses on enhancing PV systems through the use of gallium arsenide (GaAs) thin films and reviews techniques like spectral beam splitting to boost efficiency, particularly in multi-junction PV receivers and hybrid collectors. The study also explores Photovoltaic-thermal (PVT) systems that combine PV cells with thermal absorbers, highlighting advanced absorber designs, mini/microchannels, and the use of polymers over traditional metals.

Review on Nanofluids: Preparation, Properties, Stability, and Thermal Performance Augmentation in Heat Transfer Applications.

Nanoparticles play a crucial role in enhancing the thermal and rheological properties of nanofluids, making them a valuable option for increasing the efficiency of heat exchangers. This research explores how nanoparticle characteristics, such as concentration, size, and shape, impact the properties of nanofluids. Nanofluids' thermophysical properties and flow characteristics are essential in determining heat transfer efficiency and pressure loss.

Retention mechanisms of dipeptides on superficially porous particle vancomycin- and teicoplanin-based chiral stationary phases.

Chromatographic behavior of new chiral stationary phases (CSPs) Chiral-T and Chiral-V with teicoplanin and vancomycin antibiotics grafted onto superficially porous silica particles was studied in relation to dipeptide (DP) stereoisomers. The unbuffered water-methanol solutions were used as mobile phases (MPs). The effects of physical properties and molecular structure of analytes and selectors on retention and separation of DP stereoisomers are discussed herein.

Effect of Flavonols of Fruits on Morphofunctional State of Immunocompetent Organs of Rats under Cyclophosphamide-Induced Immunosuppression.

berries contain many compounds with potential benefits for human health. The food flavonoids quercetin and rutin, found in significant amounts in the fruits of , are known to have favourable effects on animal and human organisms. However, data on the effect of flavonols isolated from black chokeberry on immune functions during immunosuppression are not available in the literature.

Expanding Mn loading capacity of BSA via mild non-thermal denaturing and cross-linking as a tool to maximize the relaxivity of water protons.

Development of nanoparticles (NPs) serving as contrast enhancing agents in MRI requires a combination of high contrasting effect with the biosafety and hemocompatibility. This work demonstrates that bovine serum albumin (BSA) molecules bound to paramagnetic Mn ions are promising building blocks of such NPs. The desolvation-induced denaturation of BSA bound with Mn ions followed by the glutaraldehyde-facilitated cross-linking provides the uniform in size 102.

A supramolecular assembly of sulfobutyl ether-β-cyclodextrin and viologen calix[4]resorcinol as the master key to sustainable and eco-friendly catalyst for paraoxon hydrolysis.

The search for effective ways of paraoxon (POX) degradation becomes an extremely urgent problem, which can be solved by creating effective bioscavengers in the form of three-dimensional macrocycles. In this work, supramolecular interactions in an aqueous medium were studied between (4-sulfobutyl)-β-cyclodextrin, the hydrophobic cavity of which is capable of binding POX, and viologen calix[4]resorcinol, the cationic groups of which are able to facilitate the nucleophilic attack on the phosphorus atom of the pesticide. A complex of physicochemical methods revealed the nature of the interactions between these cyclodextrin and calix[4]resorcinol, as a result of which the spontaneous formation of nanoparticles occurs.

Specificity of hexarhenium cluster anions for synthesis of Mn-based nanoparticles with lamellar shape and pH-induced leaching for specific organ selectivity in MRI contrasting.

The present work demonstrates the structure variation of hexarhenium anionic cluster units [{ReS}(CN)(OH)] (n = 0, 2, 4) as the strategy to develop Mn-containing nanoparticles (NPs) exhibiting pH-dependent leaching. The dicyanotetrahydroxo complex [{ReS}(CN)(OH)] is the optimal for the synthesis of the Mn-based NPs with a lamellar shape exhibiting the pH-dependent aggregation and magnetic relaxation behavior. The pH-dependent behavior of the NPs derives from the easy protonation of the apical hydroxo ligands of [{ReS}(CN)(OH)] cluster, which triggers partial leaching of Mn ions and aggregation of the NPs driven by the surface neutralization.

The Reduction of Carbonyl Compounds with Dicyclopentylzinc: A New Example of Asymmetric Amplifying Autocatalysis.

A previously unknown reduction of carbonyl compounds with dicyclopentylzinc is reported. Aldehydes react in mild conditions yielding corresponding primary alcohols and cyclopentene. Although cyclohexanone and acetophenone are inert to dicyclopentylzinc, a variety of heterocyclic ketones reacted readily, yielding reasonable to high yields of corresponding secondary alcohols.

A supramolecular catalyst based on sodium alginate and viologen calix[4]resorcinol for the room temperature hydrolysis of paraoxon.

Properties of paraoxon, such as poor water solubility, low rate of natural decomposition, ability to accumulate in soil and wastewater, lead to the fact that paraoxon is found in various agricultural products and textiles. In this regard, the search for effective ways of paraoxon degradation becomes an extremely urgent problem, which can be solved by creating catalysts by mimicking paraxonase. In this work, a complex of physicochemical methods was used to study the supramolecular interactions of sodium alginate, which has a calcium-binding ability similar to paraxonase, with viologen calix[4]resorcinol and to reveal the nature of the intermolecular interactions between them resulting in the spontaneous formation of nanoparticles.

Divergent Synthesis of 3-(Indol-2-yl)quinoxalin-2-ones and 4-(Benzimidazol-2-yl)-3-methyl(aryl)cinnolines via Polyphosphoric Acid (PPA)-Mediated Intramolecular Rearrangements of 3-(Methyl/aryl(2-phenylhydrazono)methyl)quinoxalin-2-ones.

Herein, we report a polyphosphoric acid (PPA)-mediated divergent metal-free operation to access a diverse collection of 3-(indol-2-yl)quinoxalin-2-ones and 4-(benzimidazol-2-yl)-3-methylcinnolines in moderate to excellent overall yields. The described process involves two distinct, and competing rearrangements of 3-(methyl(2-phenylhydrazono)methyl)quinoxalin-2-ones, namely [3,3]-sigmatropic Fischer rearrangement with the formation of an indole ring to produce 3-(indol-2-yl)-quinoxalin-2-ones, and Mamedov rearrangement with simultaneous construction of benzimidazole and cinnoline rings to form the new biheterocyclic system─4-(benzimidazol-2-yl)-3-methylcinnolines. The reaction mechanism of both rearrangement channels is explored by extensive dispersion-corrected DFT calculations.

Evidence of extremely short hydrogen bond in the homoconjugated ferrocene-1,1'-diyl-bisphosphinic acid anion: sign change of the H/D isotope effect on the P NMR chemical shift.

The structure of the two intramolecular hydrogen-bonded motifs within ferrocene-1,1'-diyl-bisphosphinic acid, a cyclic dimer and a homoconjugated anion, has been experimentally revealed by NMR spectroscopy for a solution in a low-freezing polar aprotic CDF/CDFCl medium at 100 K. Structure elucidation was achieved with the help of the H/D isotope effects on the H, H and, for the first time, P NMR chemical shifts. The questions of bridging hydron localization and origins of opposite signs of H/D isotope effects on the P NMR chemical shifts in the cyclic dimer and homoconjugated anion have also been addressed by DFT calculations, including numerical solution of the Schrödinger equation for proton and deuteron vibrations in the anharmonic double well potentials.

Five Different L. Species Ethanol Extracts' Phytochemical Composition and Their Antimicrobial and Nematocide Activity.

Among the plants that exhibit significant or established pharmacological activity, the genus L. deserves special attention. This genus comprises over 500 species belonging to the largest family.

NMR-Relaxometric Investigation of Mn(II)-Doped Polyoxometalates in Aqueous Solutions.

Solution behavior of K;[(Mn(HO))PWO]·7HO (), Na(NH)H[(Mn(HO))(WO(HO))(α-B-SbWO)]·27HO (), and NaH[(Mn(HO))(WO)(β-B-TeWO)]·19HO () was studied with NMR-relaxometry and HPLC-ICP-AES (High Performance Liquid Chromatography coupled with Inductively Coupled Plasma Atomic Emission Spectroscopy). According to the data, the [(Mn(HO))PWO] Keggin-type anion is the most stable in water among the tested complexes, even in the presence of ethylenediaminetetraacetic acid (EDTA) or diethylenetriaminepentaacetic acid (DTPA). Aqueous solutions of and anions are less stable and contain other species resulting from dissociation of Mn.

Antioxidative and Immunomodulating Properties of Extract Rich in Anthocyanins.

The fruits of are well known due to their high anthocyanin content that may be effective in preventing certain health disorders arising from oxidative stress. Various polyphenolic compounds such as anthocyanins and flavonoids are responsible for the multiple effects of chokeberry. The aim of this study was to determine in vitro how active the black chokeberry anthocyanins are in scavenging radicals and to evaluate in vivo their immunomodulating capacity.

Liquid-Crystalline Order in the Phosphorus-Containing DenDrimers.

The structure of phosphorus-containing dendrimers has been studied by IR spectroscopy and optical polarization microscopy. The repeating units of dendrimer molecules are mesogens. This property arises from the conjugation of the aromatic ring and the hydrazone group.

Synthesis, structure, and biological activity of 4-hetaryl-2-pyrrolidones containing a pyrazole ring.

Unlabelled: Single diastereomers of 4-hetaryl-2-pyrrolidone-3(5)-carbo- and 2-[4-hetaryl-2-pyrrolidon-1-yl]acetohydrazides were used in reactions with 2,4-pentanedione, providing (3,4)-3-, (4,5)-5-(3,5-dimethyl-1-pyrazole-1-carbonyl)- and 1-[2-(3,5-dimethyl-1-pyrazol-1-yl)-2-oxoethyl]-4-hetaryl-2-pyrrolidones. The structures of the synthesized compounds were confirmed by spectral methods and X-ray structural analysis. Some of the obtained compounds were shown to possess nootropic and anxiolytic activity.

Synthesis of Morpholine-, Piperidine-, and -Substituted Piperazine-Coupled 2-(Benzimidazol-2-yl)-3-arylquinoxalines as Novel Potent Antitumor Agents.

A novel series of 2-(benzimidazol-2-yl)quinoxalines with three types of pharmacophore groups, namely, piperazine, piperidine, and morpholine moieties, which are part of known antitumor drugs, was designed and synthesized. The compounds have been characterized by NMR and IR spectroscopy, high- and low-resolution mass spectrometry, and X-ray crystallography. 2-(Benzimidazol-2-yl)quinoxalines with -methylpiperazine substituents showed promising activity against a wide range of cancer lines, without causing hemolysis and showing little cytotoxicity against normal human Wi-38 cells (human fetal lung).

Bromine-Promoted One-Pot Furo[]annulation and α-C(sp)-Thiomethylation Cascade of ()-3-Styrylquinoxalin-2(1)-ones with Dimethyl Sulfoxide.

A new process has been developed for the bromine-promoted sequential (sp)C = (sp)C bond functionalization of ()-3-styrylquinoxalin-2(1)-ones and furo[]annulation via the 5-cyclization in dimethyl sulfoxide (DMSO). The reaction represents a novel strategy for the synthesis of 2-aryl-3-(methylthio)furo[2,3-]quinoxalines and involves 3-(1,2-dibromo-2-arylethyl)quinoxalin-2(1)-ones and 2-arylfuro[2,3-]quinoxalines as key intermediates. Furthermore, DMSO was converted to dimethyl sulfide in situ, which served as the methylthiolation reagent in the reaction.

Molecular and Nano-Structural Optimization of Nanoparticulate Mn-Hexarhenium Cluster Complexes for Optimal Balance of High T- and T-Weighted Contrast Ability with Low Hemoagglutination and Cytotoxicity.

The present work introduces rational design of nanoparticulate Mn(II)-based contrast agents through both variation of the μ (inner) ligands within a series of hexarhenium cluster complexes [{Re(μ-Q)}(CN)] (ReQ, Q = S, Se or Te) and interfacial decoration of the nanoparticles (NPs) KMnReQ ( = 1.3 - 1.8) by a series of pluronics (F-68, P-123, F-127).

Editorial of Special Issue "The Self-Assembly and Design of Polyfunctional Nanosystems 2.0".

The intention of this Special Issue, entitled "The Self-Assembly and Design of Polyfunctional Nanosystems 2 [...