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High-temperature polymer-electrolyte membrane fuel cells (HT-PEMFCs) are a very important type of fuel cells since they operate at 150–200 °C, making it possible to use hydrogen contaminated with CO. However, the need to improve the stability and other properties of gas-diffusion electrodes still impedes their distribution. Self-supporting anodes based on carbon nanofibers (CNF) are prepared using the electrospinning method from a polyacrylonitrile solution containing zirconium salt, followed by pyrolysis. After the deposition of Pt nanoparticles on the CNF surface, the composite anodes are obtained. A new self-phosphorylating polybenzimidazole of the 6F family is applied to the Pt/CNF surface to improve the triple-phase boundary, gas transport, and proton conductivity of the anode. This polymer coating ensures a continuous interface between the anode and proton-conducting membrane. The polymer is investigated using CO2 adsorption, TGA, DTA, FTIR, GPC, and gas permeability measurements. The anodes are studied using SEM, HAADF STEM, and CV. The operation of the membrane–electrode assembly in the H2/air HT-PEMFC shows that the application of the new PBI of the 6F family with good gas permeability as a coating for the CNF anodes results in an enhancement of HT-PEMFC performance, reaching 500 mW/cm2 at 1.3 A/cm2 (at 180 °C), compared with the previously studied PBI-O-PhT-P polymer. [ABSTRACT FROM AUTHOR]

Pharmacologic inhibitors of cellular hydroxylase oxygen sensors are protective in multiple preclinical in vivo models of inflammation. However, the molecular mechanisms underlying this regulation are only partly understood, preventing clinical translation. We previously proposed a new mechanism for cellular oxygen sensing: oxygen-dependent, (likely) covalent protein oligomer (oxomer) formation. Here, we report that the oxygen sensor factor inhibiting HIF (FIH) forms an oxomer with the NF-κB inhibitor β (IκBβ). The formation of this protein complex required FIH enzymatic activity and was prevented by pharmacologic inhibitors. Oxomer formation was highly hypoxia-sensitive and very stable. No other member of the IκB protein family formed an oxomer with FIH, demonstrating that FIH-IκBβ oxomer formation was highly selective. In contrast to the known FIH-dependent oxomer formation with the deubiquitinase OTUB1, FIH-IκBβ oxomer formation did not occur via an IκBβ asparagine residue, but depended on the amino acid sequence VAERR contained within a loop between IκBβ ankyrin repeat domains 2 and 3. Oxomer formation prevented IκBβ from binding to its primary interaction partners p65 and c-Rel, subunits of NF-κB, the master regulator of the cellular transcriptional response to pro-inflammatory stimuli. We therefore propose that FIH-mediated oxomer formation with IκBβ contributes to the hypoxia-dependent regulation of inflammation. [ABSTRACT FROM AUTHOR]

Heterocycles functionalized with pentavalent phosphorus are of great importance since they include a great variety of biologically active compounds and pharmaceuticals, advanced materials, and valuable reactive intermediates for organic synthesis. Significant progress in synthesis of P(O)R2-substituted six-membered heterocycles has been made in the past decade. This review covers the synthetic strategies towards aromatic monocyclic six-membered N-heterocycles, such as pyridines, pyridazines, pyrimidines, and pyrazines bearing phosphonates and phosphine oxides, which were reported from 2012 to 2022. [ABSTRACT FROM AUTHOR]

Significance: Limited oxygen availability (hypoxia) commonly occurs in a range of physiological and pathophysiological conditions, including embryonic development, physical exercise, inflammation, and ischemia. It is thus vital for cells and tissues to monitor their local oxygen availability to be able to adjust in case the oxygen supply is decreased. The cellular oxygen sensor factor inhibiting hypoxia-inducible factor (FIH) is the only known asparagine hydroxylase with hypoxia sensitivity. FIH uniquely combines oxygen and peroxide sensitivity, serving as an oxygen and oxidant sensor. Recent Advances: FIH was first discovered in the hypoxia-inducible factor (HIF) pathway as a modulator of HIF transactivation activity. Several other FIH substrates have now been identified outside the HIF pathway. Moreover, FIH enzymatic activity is highly promiscuous and not limited to asparagine hydroxylation. This includes the FIH-mediated catalysis of an oxygen-dependent stable (likely covalent) bond formation between FIH and selected substrate proteins (called oxomers [oxygen-dependent stable protein oligomers]). Critical Issues: The (patho-)physiological function of FIH is only beginning to be understood and appears to be complex. Selective pharmacologic inhibition of FIH over other oxygen sensors is possible, opening new avenues for therapeutic targeting of hypoxia-associated diseases, increasing the interest in its (patho-)physiological relevance. Future Directions: The contribution of FIH enzymatic activity to disease development and progression should be analyzed in more detail, including the assessment of underlying molecular mechanisms and relevant FIH substrate proteins. Also, the molecular mechanism(s) involved in the physiological functions of FIH remain(s) to be determined. Furthermore, the therapeutic potential of recently developed FIH-selective pharmacologic inhibitors will need detailed assessment. Antioxid. Redox Signal. 37, 913–935. [ABSTRACT FROM AUTHOR]

New chalcogen–nitrogen π-heterocycles covering 3,1,2,4-benzothiaselenadiazines, 1,3,2,4-benzodithiadiazines and 1,2,4,3,5-benzotrithiadiazepines were synthesized via the electrophilic cyclization of compounds Ar–N＝S＝N–SiMe3 under the action of SeCl2, SeCl4/FeCp2, SCl2 and S2Cl2. Heterocycles obtained were thermolyzed into persistent 2,1,3-benzothiaselenazolyls and 1,2,3-benzodithiazolyls (Herz radicals), which were characterized using EPR spectroscopy and DFT calculations. Reaction of the archetypal 3,1,2,4-benzothiaselenadiazine with SCl2 afforded 2,1,3-benzothiaselenazolium chloride (Herz salt), whereas that of sterically hindered 1,3,2,4-benzodithiadiazine resulted in a complex of the corresponding Herz salt with unexpected carbocycle-chlorinated and non-chlorinated 3,3-dioxides of the starting material, which is a rare example of a molecular complex involving a Herz cation. Formation of the dioxides can be explained through intermediate participation of the benzodithiadiazine radical cation. Hydrolysis of 3,1,2,4-benzothiaselenadiazine or 1,3,2,4-benzodithiadiazine led to Se-(2-aminophenyl)selenosulfate (Se-Bunte salt) or S-(2-aminophenyl)thiosulfate (Bunte salt), respectively. [ABSTRACT FROM AUTHOR]

In recent years, the transition‐metal catalyzed three‐component coupling of an aldehyde, an alkyne and an amine, commonly called A3 coupling has become a powerful tool in organic synthesis. The aim of this review is to give a general overview of A3 coupling utility in the synthesis of heterocycles, highlighting the variety of compounds that can be directly accessed from single reactions. The diverse A3 coupling based methodologies that have been developed for the synthesis of N,O,S‐heterocycles are presented, emphasizing the influence of the reaction conditions and the use of additional reagents in the outcome of the transformations. [ABSTRACT FROM AUTHOR]

Chemistry and materials science of Herz radicals (1,2,3-benzodichalcogenazolyls; chalcogen is S or Se) are discussed including their synthesis, structure and reactivity. Preparation and functional characterization of radical-based molecular conducting and magnetic materials are considered. [ABSTRACT FROM AUTHOR]

A new synthetic methodology based on the self-condensation of 1,2,3-benzodithiazolyl diradicals (Herz radicals) produces unprecedented 5-6-6-6-5 and 5-6-7-6-5 pentacyclic sulfur-nitrogen near-IR dyes featuring up to five multiple long-lived and differently coloured redox-states. [ABSTRACT FROM AUTHOR]

Unique derivatives of androstene and estrane series containing N -sulfonylimidate pendants were prepared from 17 α -ethynyl steroids via Cu-catalyzed azide–alkyne cycloaddition to tosyl azide in the presence of alcohols. The synthesized compounds were screened for cytotoxicity against human breast cancer cell lines and ERα agonist activity. The hit compound 3,17 β -dimethoxy-17 α -[ iso -propyl-2′- N -tosylacetimidate]estra-1,3,5(10)-triene (4n) had no ERα-mediated hormonal activity and was found to exhibit potent cytotoxic effect in an ERα-positive breast cancer cell line. N -Sulfonylimidate 4n displayed high antiproliferative potency against triple-negative MDA-MB-231 breast cancer cells, while it was non-toxic towards normal mammary epithelial cells. Compound 4n was found to alter activity of various signaling pathways (NF-κB, Slug, cyclin D1, ERK) supporting the growth and invasiveness of tumor cells. Image 1 • A broad series of novel steroidal N -sulfonylimidates were prepared and screened for activity against breast cancer cells. • Hit compound 4n showed no agonist activity against ERα and exhibited high antiproliferative activity against breast cancer cells. • The structure–activity relationship data for steroidal N -sulfonylimidates are summarized. • Hit compound 4n proved to be active against triple-negative MDA-MB-231 breast cancer cells and non-toxic in MCF-10A cells. • Hit compound 4n altered activity of various signaling pathways (NF-κB, Slug, cyclin D1, ERK). [ABSTRACT FROM AUTHOR]

Recent developments in the synthesis of imidazo[1,2- a]pyridines via the transition metal-catalyzed three-component heterocyclization of aldehyde, 2-aminopyridine, and alkyne are discussed in this highlight. [ABSTRACT FROM AUTHOR]

This brief review describe the recent advances in using oxamic acid thiohydrazides as precursors for the formation of hydrazones intermediates from natural and synthetic compounds bearing a carbonyl group. These intermediates undergo a variety of synthetically useful transformations, which include nucleophilic addition and 6π-electrocyclic reactions to generate new heterocycles. [ABSTRACT FROM PUBLISHER]

The archetypal 3,1,2,4-benzothiaselenadiazine, its 5- and 8-Me 3 Si derivatives and related dithiadiazine and trithiadiazepine were synthesized from 2-Me 3 SiC 6 H 4 N=S=NSiMe 3 by the action of SeCl 2 , SeCl 4 , SCl 2 , and S 2 Cl 2 and converted into persistent 2,1,3-benzothiaselenazolyl and 1,2,3-benzodithiazolyl radicals characterized by EPR spectroscopy and DFT calculations. [ABSTRACT FROM AUTHOR]

An elegant approach to unknown steroidal imidazo[1,2- a ]pyridine hybrids is disclosed. Unique derivatives of androstene and estrane series containing imidazo[1,2- a ]pyridine motifs were prepared from 17-ethynyl steroids in good yields via copper-catalyzed cascade aminomethylation/cycloisomerization with imines. The synthesized compounds were screened for cytotoxicity against human breast (MCF-7, MDA-MB-231, HBL-100, MDA-MB-453) and prostate (LNCaP-LN3, PC-3, DU 145) cancer cell lines. The majority of tested compounds showed activities at μM level in breast cancer cells. The hormone-responsive breast cancer cells MCF-7 were more sensitive to novel compounds than ERα-negative cells; in particular, compounds 6a , b exhibited promising cytotoxicity against this cell line with the IC 50 values in the range of 3–4 μM. Furthermore, compound 4a showed remarkable effects as a selective ERα receptor modulator. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of hybrid molecules based on Avermectin and imidazopyridine pharmacophores acting as GABA A Rs PAMs were designed. • In each of these series lead compounds were discovered using a radioligand competition binding assay. • Structural basis for activity of lead-compounds were proposed using extensive molecular docking studies. • The functional properties of highest-affinity compound as GABA A Rs PAM were determined by electrophysiological measurements. • Biological efficacy of hybrid molecules was demonstrated in vivo in behavioral assays using adult zebrafish. The γ-aminobutyric acid type A (GABA A) receptors are pentameric transmembrane protein complexes. They have attracted extensive attention from the scientific community due to their significant pharmacological potential. Here we report the first synthesis of avermectin–imidazo[1,2- a ]pyridine hybrids promising as GABA A receptor positive allosteric modulators (PAMs). An efficient multi-step protocol was elaborated for the installation of the 6-methyl-2-(p- tolyl)imidazo[1,2- a ]pyridine pendant to the Avermectin B 1a and Ivermectin skeletons through a linker. A variety of linkers were used in order to study the effect of disturbances in the hybrid structure on the GABA A receptor affinity. In vitro experiments showed that the lead compounds exhibited high potency (IC 50 = 207 and 359 nM) for binding at the benzodiazepine site of GABA A receptors. In silico studies suggest that the hybrids are able to bind at the Ivermectin binding site of the GABA A receptor. The functional properties of the highest-affinity hybrid (compound 15e) as GABA A R PAM were evaluated by patch-clamp electrophysiological recordings of GABA-mediated currents in rat cerebellar Purkinje neurons. The results obtained suggest that the potentiating effect of hybrid compound 15e is due to its interaction both with benzodiazepine- and Ivermectin-binding sites of GABA A Rs. Drug-induced behavioral responses in adult zebrafish for hybrids correlate with an alternative mode of action of avermectin and imidazo[1,2- a ]pyridine pharmacophores. The investigation of avermectin–imidazo[1,2- a ]pyridine hybrid molecules with activity as GABA A receptor modulators is important for the discovery of safe and effective drugs for the treatment of neurological disorders and pest control agents. [ABSTRACT FROM AUTHOR]

Semi-ladder high-molecular polynaphthoylenebenzimidazoles (PNBI) were synthesized through polyaminonaphtoyleneimide (PANI) formation and thermal cyclization at 350 °C. The structures of PANIs and PNBIs were confirmed by NMR, GPC and FTIR. Polymer films were obtained from PANI pre-polymer by solution-cast technique. After thermal cyclization, the PNBI films exhibit excellent mechanical properties: tensile strength of 95–174 MPa, Young's modulus of 1.5–2.4 GPa and elongation at break of 10–50%. The PNBIs are located near the upper bound of the 1991 Robeson diagram for O 2 /N 2 , H 2 /N 2 and H 2 /CH 4 gas pairs, while the PNBI with a hexafluoroisopropylidene bridge (PNBI-4) overcomes it for CO 2 /CH 4 , approaching the upper bound of the 2008 Robeson diagram. A peculiarity of the synthesized polymers is lower gas diffusion coefficients and higher gas solubility coefficients, which are close to polypyrrolones and PIM family polymers. The higher PNBI diffusion selectivity identifies them as organic molecular sieves, as confirmed by the specific surface area of PNBI-4, which is close to PIM-1. The data obtained allows to classify the studied PNBIs as unexpected PIM relatives. The synthesized PNBIs are polymer molecular sieves and, unexpectedly, belong to the polymer of intrinsic microporosity family. [Display omitted] • The PNBI gas transport properties have been obtained. • The studied PNBIs lie on the upper bounds of the 1991 Robeson diagrams. • PNBI-4 is higher than the upper bound on the 1991 Robeson diagram for CO 2 /CH 4. • PNBI-4 is approaching the upper bound of the 2008 Robeson diagram for CO 2 /CH 4. • PNBI-4 possesses a microporous structure similar to the one of PIM-1. [ABSTRACT FROM AUTHOR]

Selective nucleophilic aromatic substitutions with several polyamines were performed in very good yields on halogeno-phenyl BODIPY derivatives containing an activating nitro group. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of a series of BODIPY derivatives substituted with acyclic and cyclic polyamines, in particular, cyclen and homocyclen, are reported. The 19F NMR, UV/Vis, and fluorescence spectroscopic data of these compounds are discussed. One compound was found to be very selective for CuII ions, which makes it a very promising system for CuII detection. [ABSTRACT FROM AUTHOR]

Quo vadis? The Lewis acid catalyzed reaction of (hetero)aryl‐derived donor–acceptor cyclopropanes with alkenes can be selectively directed along a [3+2] annulation pathway (see scheme). This new process provides convenient and efficient access to indanes and other cyclopentannulated (hetero)arenes, among which polyoxygenated 1‐arylindanes exhibit significant cytotoxicity against several cancer cell lines with an IC50 of 10−6–10−5 M. [ABSTRACT FROM AUTHOR]

Abstract: A convenient method for the preparation of functionalized β-nitroalkenes based on the nitration of α,α-di- and α,α,β-trisubstituted unsaturated aldehydes, ketones and esters with tetranitromethane in the presence of triethylamine is described. Series of substituted β-nitroalcohols and β-nitroalkenes are obtained in good yields under mild conditions. [Copyright &y& Elsevier]

Novel reaction of tetranitromethane (TNM) with electrophilic alkenes in the presence of triethylamine yielding substituted 3-nitroisoxazoles was found and studied. Triethylamine increases the reactivity of TNM toward electrophilic alkenes promoting their heterocyclization, and the reactions proceed in an unusual way. A variety of α,β-unsaturated aldehydes, ketones, esters, amides, phosphonates, and nitro and sulfur compounds was involved in the heterocyclization reaction, and a wide range of functionalized 3-nitroisoxazoles was obtained in good to high yields. The scope and limitations of the reaction and the mechanistic aspects are discussed. [ABSTRACT FROM AUTHOR]

The article discusses methods of synthesis of sulfonyl-1,2,3-triazoles including the direct sulfonation with sulfonyl chlorides and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction of acetylenes with sulfonyl azides. It also presents that these reactions are precursors for the generation of N-sulfonylketenimines and azavinyl carbenes. It also discusses reactions of N-nucleophiles with ketenimines for synthesis of nitrogen, oxygen-heterocycles.

This study aimed to examine the biological activities of unique steroid hormone derivatives – steroidal imidazoheterocycles. The activity synthesized steroidal compounds were tested for the viability of JEG-3 trophoblast cells of choriocarcinoma. The results of the MTT cytotoxicity test showed that most of the examined steroidal imidazoheterocycles act proliferatively on the JEG-3 cell line, except (E, F, and J). Antiproliferative activity of these derivates is probably influenced by different substituents at position 17-C atom in the chemical structure of the hormone and by different substituents on the oxygen atom of acetamide group in the hormone molecule. In order to better confirm the antiproliferative activity of these derivatives, it is necessary to performed complex research on a large panel of cancer cell lines and by different assay. [ABSTRACT FROM AUTHOR]

Review: [26 refs. [ABSTRACT FROM AUTHOR]

A new clean method - reductive heterocyclization of bis( o-nitoanilines) in formic acid/water media with hydrogen on Pd/C catalyst - was used to obtain new bis(benzimidazole) monomers. The monomers were involved in nucleophilic aromatic substitution reaction with 4,4′-diflourodiphenylsulphone for the synthesis of poly(N-phenylenebenzimidazoles) - a novel type of high performance polymers from the polybenzimidazole family. The obtained polymers were characterized by NMR, FTIR, GPC, TGA and TMA data. [ABSTRACT FROM AUTHOR]

A general, practical, and simple synthesis of functionalized 2-aminopyrimidines starting from β-chlorovinyl aldehydes and amidines is reported. In the presence of potassium carbonate, various ketones have been efficiently transformed into the pyrimidine derivatives by a two-step sequence involving the Vilsmeier–Haack reaction followed by a condensation reaction with guanidines. The protocol is distinguished by operational simplicity, inexpensive reagents, and functional-group tolerance. In many cases, pure solid products can be obtained in high to excellent yields without using column chromatography. The synthetic value of the method was demonstrated by the efficient synthesis of steroidal pyrimidines and a precursor of the antitumor agents Imatinib and Mocetinostat. [ABSTRACT FROM AUTHOR]

A new simple approach to the synthesis of cyclopentannulated (hetero)arenes is developed. [ABSTRACT FROM AUTHOR]

Novel derivatives of 4,4‐difluoro‐1,3,5,7,8‐pentamethyl‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) functionalized at the meso‐position with polyamines and polyoxyethylenes were synthesized through single‐step condensation of fluorogenic 8‐CH2Cl‐substituted BODIPY and corresponding amines. The systematic spectroscopic characterization (UV‐Vis, fluorescence) of stable in storage dyes bearing polyoxyethylene substituents was carried out. One compound showed promise for UV‐Vis and "off‐on" fluorescence Cu2+ detection in acetonitrile solutions. The ligand detects Cu2+ ions selectively in the presence of eighteen different alkaline earth metal cations. [ABSTRACT FROM AUTHOR]

Heterocyclic organophosphorus compounds have remarkable properties and a great deal of potential to meet contemporary societal demands regarding health, environment, energy, and information technologies. Here, we report highly reactive phosphorylthioformic acid hydrazides as novel polyheteroatom reagents for the concise synthesis of phosphorus-substituted medium–ring aza-heterocyclic systems. The reaction of phosphorylthioformic acid hydrazides with functionalized aldehydes was systematically investigated. Chemoselective and flexible synthetic approaches to phosphorus(V)-substituted 1,3,4-thiadiazoles, 1,3,4-thiadiazolines, and pyridazines were developed. Phosphorylthioformic acid hydrazides proved to be useful for the preparation of phosphorus(V)-containing heterocyclic steroid derivatives. [Display omitted] [ABSTRACT FROM AUTHOR]

This study reports the first general, practical, and facile synthesis of phosphorus-substituted 1,3,4-thiadiazolines starting from phosphorylthioformic acid hydrazides and ketones. Various cyclic ketones were efficiently incorporated into spiro 1,3,4-thiadiazoline derivatives by a two-step sequence involving the heterocyclization with phosphorylthioformic acid hydrazides followed by the nitrogen acylation with acyl chlorides. The protocol is characterized by operational simplicity, readily available reagents, and functional group tolerance. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Revised regiochemistry for the heterocyclization of electrophilic alkenes with tetranitromethane (TNM) in the presence of triethylamine, providing rapid access to nitroisoxazoles, is reported. The formation of 5-nitroisoxazoles previously incorrectly assigned as 3-nitro regioisomers, has now been established unambiguously by X-ray crystallography. Empirical computations with ACD/CNMR Predictor, based both on hierarchical ordering of spherical environments (HOSE) and an algorithm of artificial neural networks (ANN), and also Density Functional Theory computations of the 13C NMR chemical shifts for the 3- versus 5-nitroisoxazoles are shown to consistently match the spectra of the experimentally observed 5-regioisomers. [Copyright &y& Elsevier]

The sulfonated polynaphthoyleneimide polymer (co-PNIS70/30) was prepared by copolymerization of 4,4′-diaminodiphenyl ether-2,2′-disulfonic acid (ODAS) and 4,4'-methylenebisanthranilic acid (MDAC) with ODAS/MDAC molar ratio 0.7/0.3. High molecular weight co-PNIS70/30 polymers were synthesized either in phenol or in DMSO by catalytic polyheterocyclization in the presence of benzoic acid and triethylamine. The titration reveals the ion-exchange capacity of the polymer equal to 2.13 meq/g. The membrane films were prepared by casting polymer solution. Conductivities of the polymer films were determined using both in- and through-plane geometries and reached ~96 and ~60 mS/cm, respectively. The anisotropy of the conductivity is ascribed to high hydration of the surface layer compared to the bulk. SFG NMR diffusometry shows that, in the temperature range from 213 to 353 K, the 1H self-diffusion coefficient of the co-PNIS70/30 membrane is about one third of the diffusion coefficient of Nafion® at the same humidity. However, temperature dependences of proton conductivities of Nafion® and of co-PNIS70/30 membranes are nearly identical. Membrane–electrode assemblies (MEAs) based on co-PNIS70/30 were fabricated by different procedures. The optimal MEAs with co-PNIS70/30 membranes are characterized by maximum output power of ~370 mW/cm2 at 80 °C. It allows considering sulfonated co-PNIS70/30 polynaphthoyleneimides membrane attractive for practical applications. [ABSTRACT FROM AUTHOR]

New PIM-1 copolymers with 2,3,6,7-anthracenetetrayl moiety have been synthesized as fine powders from 2,3,6,7-tetrahydroxy-9,10-di(p -fluorophenyl)anthracene monomer in DMSO, with crystal structure of the monomer as well as its precursors and the product of its model side crosslinking reaction being determined using X-ray diffraction. The microporosity and surface characteristics of the copolymers powders have been measured. As-cast membrane from the copolymer with 5 mol% of the monomer synthesized revealed promising gas separation properties as compared with original PIM-1. [ABSTRACT FROM AUTHOR]

A new approach to the synthesis of polynaphthoylenebenzimidazoles and heat resistant fiber spinning has been developed using an environmentally friendly and energy efficient method, which operates with solutions of pre-polymers based on 3,3',4,4'-tetraaminodiphenyl ether and 1,4,5,8-naphthalenetetracarboxylic acid dianhydride in N-methylpyrrolidone. Rheological properties of polymer reaction solutions and appropriate coagulant mixtures were investigated for further wet spinning process. The coagulation process was investigated through microscopic observation of solution droplets which imitate jet/fiber cross section surrounded with coagulants of different composition. For the case of the most optimal viscoelastic properties of dopes the best coagulant was found to be a ternary mixture ethanol/water/NMP (20/10/70). Fibers were prepared through the wet spinning from pre-polymers of various molecular weight characterized by intrinsic viscosity. As a result, complex yarns were spun, and their morphology was characterized and mechanical properties were measured. The strength of ~300 MPa and elastic modulus of ~2 GPa and elongation at break of ~20% were reached for the best fibers at average diameter of ~20 µm. After heat treatment "Lola-M" fibers do not burn and do not support combustion in open flame. [ABSTRACT FROM AUTHOR]

[Display omitted] Novel spiroandrostene-17,6'-[1,3,4]thiadiazines obtained by synthesis from 16βββ,17βββ-epoxy-17-isopregn-5-en-3βββ-ol-20-one and N -aryl-2-hydrazino-2-thioxoacetamide efficiently inhibited the release of Epstein–Barr virus from cells carrying the virus in culture. Other studied steroids, such as Spirolactone, Digitonin, Diosgenin, and Hecogenin were inactive. DMSO alone was found to inhibit the virus release, as well, likely, because of changing properties of the cell membranes. The novel steroids, Spironolactone and most analogues display no or low cell toxicity while Digitonin produced a significant toxic effect. [ABSTRACT FROM AUTHOR]

A straightforward approach for the synthesis of 4-nitroisoxazoles has been developed via heterocyclization of aryl/hetaryl-substituted α,β-unsaturated ketones upon treatment with tetranitromethane-triethylamine (TNM-TEA) complex or t -BuONO. This strategy features high efficiency and wide substrate tolerance under simple reaction conditions. [ABSTRACT FROM AUTHOR]

Herein, we report the systematic evaluation of the BODIPY series functionalized with pseudo‐crown ethers against metal cations and assessment of their potential as novel off‐on fluorescent probes selective for aluminum(III) cations. [ABSTRACT FROM AUTHOR]

Heterocyclic derivatives of steroid hormones are potent anticancer agents, which are used in the chemotherapy of breast and prostate cancers. Here, we describe a novel series of androstenes, D -modified with imidazole-annulated pendants, with significant anticancer activity. Novel C17-linked imidazole-annulated heterocyclic derivatives of dehydropregnenolone acetate were synthesized by the cyclocondensation with amidines using 3β-acetoxy-21-bromopregna-5,16-dien-20-one as the substrate. The antiproliferative potency of all the synthesized compounds was evaluated against human prostate (22Rv1) and human breast (MCF7) cancer cell lines and cytochromes P450. The lead compound, imidazo[1,2- a ]pyridine derivative 3h , was revealed to be a promising candidate for future anticancer drug design, particularly against ERα-positive breast cancer. Lead compound 3h was found to be selective against MCF7 cells with IC 50 of 0.1 μM and to act as both a potent selective agent blocking estrogen receptor α, which is involved in the stimulation of breast cancer growth, and an effective apoptosis inducer. The potential ability of compound 3h to bind to ERα was studded using molecular docking and molecular dynamics simulation. The selectivity analysis showed that lead steroid 3h produces no effects on cytochromes P450 CYP17A1, CYP7A1, and CYP21A2. [Display omitted] • A series of novel androst-5,16-dienes D-modified with imidazole-annulated heterocycles was synthesized. • Their activity against human cancer cell lines, normal mammary cells, and cytochromes P450 was investigated. • Lead compound was shown to act as both an effective apoptosis inducer and a potent selective agent blocking ERα. [ABSTRACT FROM AUTHOR]

A straightforward, practical, and atom-economical three-component synthesis of phosphoryl thioamides from phosphinic chlorides, elemental sulfur, and aliphatic amines has been developed. The scope and limitations of this transformation have been investigated. This protocol is distinguished by metal- and organic solvent-free conditions, and high tolerance to various functional groups; it can be adapted for scaledup synthesis. [ABSTRACT FROM AUTHOR]

Obese African-American (AA) women are at high risk of hypertension (HT) and cardiovascular disease (CVD). Flow-mediated dilation (FMD) and arterial augmentation index (AI) are measures of endothelial function and arterial stiffness. Whether endothelial function and arterial stiffness predict risk of HT or CVD in obese African-American women with, versus without, parental histories of HT and whether aerobic exercise is an effective countermeasure remain unclear. The capacity for FMD is partly heritable. Therefore, we tested the hypotheses that less FMD and greater AI may be found in normotensive-obese, young-adult (18-26 year-old) AA women with hypertensive parents (n=10) than in a matched control group with normotensive parents (n=10) and that a single bout of aerobic exercise improves both endothelial function and arterial stiffness, with less improvement in the women with hypertensive parents. We studied each subject while at rest, 20 min before and 20 min after, 30 min of aerobic exercise. The exercise-induced changes and parental hypertension-related differences in AI were not significant. The exercise increased FMD in both of the groups with no significant difference in magnitude between the women with hypertensive and normotensive parents. FMD was significantly less in the women with hypertensive parents than in the women with normotensive parents after, but not before, the exercise (mean ±95% confidence interval of 11.3 ± 4.9% vs. 15.6 ± 4.9%, P=0.05). These findings suggest that a 30-min bout of aerobic exercise may improve FMD and unmask endothelial dysfunction in normotensive-obese, young-adult AA women with parental histories of HT. Future studies should determine whether regular aerobic exercise protects obese AA women from the endothelial dysfunction associated with diabetes and prevents CVD in this high-risk population. [ABSTRACT FROM AUTHOR]

Extensive experimental and theoretical investigations on the isomerization and heterocyclizations of β‐chlorovinyl thiohydrazones derived from oxamic acid thiohydrazides and β‐chlorovinyl aldehydes were performed to elucidate the reaction mechanism of pyridazine formation. We showed that model β‐chlorovinyl thiohydrazone undergoes multiple isomerization reactions in solution induced by thione–thiol tautomerism and Z/E‐isomerization at the C=N bond. Mechanistic rationalization along with computational studies demonstrated that pyridazine is predominantly generated from the Z‐thiol isomers by 6π‐electrocyclization of the thiohydrazone‐derived 2,3‐diazatriene intermediate. The autocatalytic character of cyclization accelerated by the formation of acid was demonstrated by means of 1H NMR monitoring. β‐Chlorovinyl aldehydes undergo a condensation reaction with oxamic acid thiohydrazides to give pyridazines. Here, we report the results of extensive experimental and some theoretical mechanistic investigation. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop mesoporous containers for entrapment of imidazopyridines, such as sedative-hypnotic medicine zolpidem, anxiolytic agent alpidem and their derivatives. For this purpose, calcium carbonate (size 1.2 µm (PDI: 0.6), zeta potential: −10 mV), manganese carbonate (2.5 µm (PDI: 0.5), zeta potential: −12 mV) and titanium dioxide particles (3.7 µm (PDI: 0.4), zeta potential: −15 mV) were used. The compounds were encapsulated applying two techniques: adsorption on the preformed particles and co-precipitation during the synthesis of the particles. The polymer shell of the containers was formed by electrostatic adsorption of polyelectrolytes on the surface of the particles. The best encapsulation efficacy was shown for zolpidem incorporated into calcium carbonate (5.4%) and manganese carbonate (4.6%) by adsorption. Release of the compounds from the containers based on the proposed particles were characterised by the short time burst effect (<10 min) followed by desorption prolongation by formation of polymer shell. X-ray microtomography results demonstrate the prolonged retention of the containers with the mucoadhesive shell in the nasal cavity. [ABSTRACT FROM AUTHOR]

Novel benzylidenes (chalcones) of the 16-dehydroprogesterone series have been characterized and their antitumor activity against two breast cancer cell lines was evaluated. Benzylidenes exhibit significant antiproliferative effect on cells and inhibit cell growth in hormone-dependent MCF-7 and hormone-independent MDA-MB-231 breast cancer cell lines. Compound 3d exhibits the highest activity against two breast cancer cell lines, with the IC 50 value of about 2 µM. Compounds 3e,m,n display considerable selectivity for hormone-dependent breast cancer cells, with the IC 50 value lower than 6 µM. Moreover, these steroidal benzylidenes regulate ERα signaling and reveal p53-independent mechanism of pro-apoptotic action in MCF-7 cells. The new class of antitumor compounds holds promise as the basis for the design of agents for cancer therapy. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Anxiolytic drug zolpidem was incorporated into the microcontainers based on mesoporous calcium carbonate particles modified by diethylaminoethyl‐dextran/hyaluronic acid shell. The release of zolpidem in saline solution and in polymer film modelling nasal mucosa was investigated. The anxiolytic effect of zolpidem upon intranasal administration of microcontainers and free medicine was determined by in vivo experiments on mice. Methods: The structures of all compounds during zolpidem synthesis were established using nuclear magnetic resonance spectroscopy. The loading efficacy and release kinetics of zolpidem were analysed by spectrophotometry. Surface morphology of formulation was investigated by scanning electron microscopy. To determine the effect of zolpidem‐loaded containers administration by the intranasal route in vivo experiments was carried out applying the open field test. Key findings: Nasal administration of zolpidem in the form of the microcontainers based on mesoporous calcium carbonate particles modified by diethylaminoethyl‐dextran/hyaluronic acid shell has a pronounced anxiolytic effect on the behaviour of the animals in the open field test. Conclusions: The polyelectrolyte shell deposited together with zolpidem enhances the loading efficacy of the microcontainers. In vivo experiments on mice demonstrate increase in anxiolytic effect of zolpidem in microcontainers compared with upon intranasal administration of free medicine. [ABSTRACT FROM AUTHOR]

The development of effective methods for real-time monitoring of nitroreductase (NTR) activity is of great significance for medical diagnosis and cancer research. Here, we present a novel water-soluble BODIPY-based chemodosimeter (NBB) for imaging the hypoxic status of human non-small-cell lung cancer A549 cells. We assume that 'on–off' response of NBB is activated by the NTRmediated reductive release of meso-phenol BODIPY dye resulting in unusual fluorescence. [ABSTRACT FROM AUTHOR]

Nitrile groups of model [1,4]benzodioxino[2,3 -b ]oxanthrene- 6,13-dicarbonitrile were transformed into quinazoline moieties by heterocyclization with benzanilides. The procedure was extended for PIM-1 modification to obtain gas separation membranes with promising permeability and selectivity. [ABSTRACT FROM AUTHOR]

Introduction: Electroencephalographically-measured frontal alpha asymmetry is shown to reflect changes in mood. Negative mood changes are purported to limit exercise capacity in some groups, thereby contributing to the current epidemic of overweight, obesity and related diseases. Aim: This study tests the hypothesis that the mood changes associated with aerobic exercise are correlated with changes in frontal EEG asymmetry. Materials and Methods: Healthy young adult African-American (AA) men (n=8) and women (n=8) were subjected to quantitative EEG brain mapping of delta, theta, alpha and beta bandwidths after a period of rest or a period of aerobic exercise at a fixed energy expenditure. Brain mapping was performed within 30 min after rest or exercise, immediately before completing a questionnaire which included a total mood disturbance score (tMDS) and specific mood subcategory scores consisting of vigor, fatigue, anger, confusion tension, depression. Prefrontal and inferior frontal asymmetry were evaluated. Significance of differences between rest and exercise prefrontal and inferior frontal asymmetry was evaluated by one-way ANOVA. Results: Exercise-related decrements in asymmetry were significant for prefrontal delta (p≤0.05) and marginally significant for prefrontal alpha and theta (p=0.07) in the male subjects. There were significant decrements in tension and tMDS for the males and females and a decrement in depression score for the females between the post-control rest and the post-exercise conditions. Significant negative correlation between the tMDS and prefrontal beta asymmetry was found, across post-rest and post-exercise (r= -0.38, p≤0.05, 30 df). There were also significant correlations between confusion and prefrontal beta asymmetry during rest (r= 0.48, p≤0.05, 14 df), between vigor and inferior frontal beta asymmetry, between vigor and both inferior frontal theta asymmetry and inferior frontal delta asymmetry during exercise (r= 0.46, -0.54, p≤0.05, 14 df), and between vigor, confusion, tension and inferior frontal delta asymmetry post-exercise (r= -0.49, -0.45, -0.49, p≤0.05, 14 df). Conclusion: The high prefrontal beta asymmetry associated with depressed mood in AA males and females, the lessening of prefrontal delta, theta and alpha asymmetry in the males and the lower depression scores after aerobic exercise in the females seem to support the hypothesis that decreased asymmetry with increased activation of the right prefrontal and frontal cortices may accompany the mood changes associated with aerobic exercise. [ABSTRACT FROM AUTHOR]

Introduction: A relatively specific quantitative Electroencephalogram (qEEG) signature is shown to be indicative of working memory deficits in low performing high school students. Previous studies have shown that Theta/Beta (T/B) ratio measured by qEEG is an indicator of poor Attention Control (AC) and that high T/B ratio may be diagnostic of attention deficit disorders. Aim: This study tests the hypothesis that high T/B ratio measured by qEEG may be associated with low academic performance in a medical school curriculum. Materials and Methods: Nine healthy male volunteers were subjected to 5-10 minutes of qEEG measurements at 19 electrode sites, under Eyes-Open (EO) and Eyes-Closed (EC) conditions. The qEEG measurements were performed for three days before each of the first two block examinations, covering standard first semester integrated basic science courses. Mean±Standard Deviations (SD) of the amplitudes, expressed in µV, and of the mode frequency in each of four standard bandwidths (delta, theta, alpha, beta), expressed in hertz, were measured. T/B ratio was then computed. Results: Mean theta and beta amplitudes increased significantly and T/B ratio decreased significantly for both the EO and EC conditions. Dominant (mode) theta frequency also increased. Overall inter and intra-hemispheric theta and beta band coherences increased for both the EO and EC conditions between the Block 1 and Block 2 exams; theta intra-hemispheric coherence was significant only for the EC condition. Correlations between Human Structure and Function (HSF) Block 2 exam scores and overall inter and intra-hemispheric coherences were significant for the beta bandwidth under the EC condition only. Conclusion: These findings suggest that high T/B ratio, a qEEG indicator of AC, may be associated with low academic performance. Future studies including a larger number of subjects should be done to determine whether these findings are gender-specific and whether lowering the T/B ratio is a predictor of medical school performance and other academic challenges. [ABSTRACT FROM AUTHOR]