Orvinol-based opioid receptor antagonist fluorinated at C(20)-pharmacophore.

Thevinols and their 3-O-demethylated relatives, orvinols, are derivatives of the Diels-Alder adduct of natural alkaloid thebaine with methyl vinyl ketone. Taken together, thevinols and orvinols constitute an important family of opioid receptor (OR) ligands playing an important role in both the OR mediated antinociception and OR antagonism. Herein, we disclose for the first time the antagonist activity of the N-allyl substituted orvinol derivative fluorinated within the pharmacophore associated with C(20) and its surrounding.

Metal (M = Cr, Mo, W, Re) carbonyl complexes with porphyrin and carborane isocyanide ligands: light-induced oxidation and carbon oxide release for antitumor efficacy.

The tetrapyrrolic macrocycle as a scaffold for various chemical modifications provides broad opportunities for the preparation of complex multifunctional conjugates suitable for binary antitumor therapies. Typically, illumination with monochromatic light triggers the photochemical generation of reactive oxygen species (ROS) (photodynamic effect). However, more therapeutically valuable effects can be achieved upon photoactivation of tetrapyrrole derivatives.

Diverse Cyclization Pathways Between Nitriles with Active -Methylene Group and Ambiphilic 2-Pyridylselenyl Reagents Enabled by Reversible Covalent Bonding.

Herein, we describe a novel coupling between ambiphilic 2-pyridylselenyl reagents and nitriles featuring an active α-methylene group. Depending on the solvent employed, this reaction can yield two distinct types of cationic pyridinium-fused selenium-containing heterocycles, 1,3-selenazolium or 1,2,4-selenadiazolium salts, in high yields. This is in contrast to what we observed before for other nitriles.

Novel β-Benzyloxy-Substituted Copolymers of Seven-Membered Cyclic Carbonate: Ring-Opening Polymerization with L-Lactide, ε-Caprolactone and Trimethylenecarbonate.

To prepare novel biodegradable copolymers with functional substituents that are distributed statistically or randomly over the macromolecule chain and have improved characteristics compared to homopolymers, we conducted a series of synthetic experiments with a novel cyclic monomer, 5-(benzyloxy)-1,3-dioxepan-2-one (). This compound was synthesized, and its homopolymer, as well as its copolymers with L-lactide, ε-caprolactone and trimethylene carbonate, were prepared in a polymerization solution with stannous octoate as the initiator. The formation of the copolymers was confirmed using NMR spectroscopy and DSC data.

Ammonium Dinitramide as a Prospective N-NO Synthon: Electrochemical Synthesis of Nitro--Azoxy Compounds from Nitrosoarenes.

In this study, the electrochemical coupling of nitrosoarenes with ammonium dinitramide is discovered, leading to the facile construction of the nitro--azoxy group, which represents an important motif in the design of energetic materials. Compared to known approaches to nitro--azoxy compounds involving two chemical steps (formation of azoxy group containing a leaving group and its nitration) and demanding expensive, corrosive, and hygroscopic nitronium salts, the presented electrochemical method consists of a single step and is based solely on nitrosoarenes and ammonium dinitramide. The dinitramide salt plays the roles of both the electrolyte and reactant for the coupling.

Design of Highly Conductive PILs by Simple Modification of Poly(epichlorohydrin--ethylene oxide) with Monosubstituted Imidazoles.

High ionic conductivity poly(ionic liquid)s (PILs) are of growing interest for their thermal and electrochemical stability, processability, and potential in safe, flexible all-solid-state electrochemical devices. While various approaches to enhance the ionic conductivity are reported, the influence of cation substituents is rarely addressed. Moreover, some of the asymmetric anions recently developed for high-conductivity ionic liquids were never tested in PILs.

Combination of phenylsilsesquioxane and acetate ligands as an approach to a record high nuclear Cu13Na2-cage. Synthesis, unique structure, and catalytic activity.

Self-assembly synthesis of mixed-ligand (silsesquioxane/acetate) complex allows to isolate record high nuclear copper(II) Cu13-cage (1). In the presence of two additional sodium ions, a unique molecular architecture, with triple combination of ligands (cyclic and acyclic silsesquioxanes as well as acetates), has been formed. The structure was established by single-crystal X-ray diffraction based on the use of synchrotron radiation.

Europium and Terbium Benzene-1,2,4,5-Tetracarboxylates: Synthesis Peculiarities, Crystal Structures, and Luminescent Thermometry up to 400 °C.

In this study, we successfully obtained for the first time a luminescent organic-based thermometer that exhibits high reproducibility, stability, and functionality up to 400 °C. Our approach involved the selection of novel highly emissive and thermally stable MOFs KEu(btec)(HO) and dehydrated KTb(btec), btec = benzene-1,2,4,5-tetracarboxylate, along with the highly thermally stable copolyimide P84 = 80% methylphenylene-diamine + 20% methylene as the matrix; luminescence lifetime was selected as a temperature-dependent parameter due to its versatility in diverse environmental conditions. Synthesis peculiarities were studied for various lanthanide benzene-1,2,4,5-tetracarboxylates, and the crystal structures of KEu(btec)(HO) and KTb(btec) were determined by Rietveld refinement from powder X-ray diffraction data.

N-Aryl Benzimidazole and Benzotriazole Derivatives and Their Hybrids as Cytotoxic Agents: Design, Synthesis and Structure-Activity Relationship Studies.

The era of chemotherapy began in the 1940s, which is the basis of traditional antitumor approaches and, being one of the most high-tech treatment methods, is still widely used to treat various types of cancer. A promising direction in modern medicinal chemistry is currently the creation of hybrid molecules containing several pharmacophore fragments of different structures. This strategy is successfully used to increase the therapeutic efficacy of cytotoxic agents and reduce side effects.

Multifunctional Dy Complexes with Triphenylmethanolates: Structural Diversity, Luminescence, and Magnetic Relaxation.

The coordination environment of magneto-luminescent Dy-based Single-Molecule Magnets (SMM) is a crucial factor influencing both magnetic and luminescent properties. In this work, we explore how triphenylmethanolate (PhCO), in combination with other ligands, can modulate the structure and, therefore, the magnetic properties of Dy-based SMM. Using triphenylmethanolate in combination with THF and pyridine (Py) as co-ligands, we synthesized a series of mononuclear -[Dy(OCPh)(THF)][BPh]·(2,6-MeCHN) (), -Dy(OCPh)(THF) (), -Dy(OCPh)(py) () and dinuclear [(PhCO)Dy(THF){(μ-Cl)Li(THF)}μ-Cl] () complexes where the Dy ion presents five- or six-coordinate geometries.

Cryostructuring of Polymeric Systems: 68. Evaluation of Poly(vinyl alcohol) Composite Cryogels Filled with Poly(3-hydroxybutyric acid)-Based Microspheres of Different Porous Morphology as Potential Delivery Systems for Drugs of Various Water-Solubility.

Poly(3-hydroxybutyric acid)-based microspheres of two types, with and without macropores, were prepared; their morphology and particle size were evaluated. These microspheres were entrapped as disperse fillers into the bulk of macroporous cryogels based on poly(vinyl alcohol) (PVA). It was found that the rigidity of the resultant composite cryogels increased markedly as compared to that of unfilled cryogels of the same PVA concentration.

An octanuclear 3-phenyl-5-(2-pyridyl)pyrazolate/phenylsilsesquioxane complex: synthesis, unique structure, and catalytic activity.

The first metallasilsesquioxane bearing pyrazolylpyridine ligands, the Cu-based complex 1, adopts a cage-like structure with two zigzag-type copper tetramers sandwiched by two cyclic Si silsesquioxane ligands. The four 3-phenyl-5-(2-pyridyl)pyrazolate ligands in 1 exhibit dual (chelating and bridging) modes of ligation. Compound 1 is very active in the oxidation of alkanes and alcohols.

Remarkable Effect of Stereoisomerism on the Am(III)/Ln(III) Solvent Extraction. New Ligands for Highly Efficient Separation of Americium.

Two novel 1,10-phenanthroline-2,9-diamide ligands were constructed on the basis of 2-phenylpyrrolidine and obtained as pure diastereomers. These ligands demonstrated advanced properties in liquid-liquid extraction tests. They revealed high efficiency of americium(III) extraction alongside with the record values of selectivity in the separation of americium from light lanthanides from strongly acidic media.

Evaluation of chelating agents based on pyridine-azacrown compounds HPATA, PATAM, and HPATPA for Ga and Lu.

In this article, we present the synthesis and characterization of three macrocyclic chelators, HPATA, PATAM, and HPATPA, based on a pyridine-azacrown compound. Their complexation with Ga and Lu has been thoroughly investigated using MALDI TOF MS, H NMR spectroscopy, radiolabeling studies, and experiments in vitro with fetal bovine serum and a 1000-fold molar excess of HEDTA. Our studies have shown that the chelators HPATA and HPATPA form complexes at room temperature with both radionuclides (RCY > 80 % and > 90 % for complexes with HPATA and HPATPA after 30 min, respectively).

Influence of triphosphine ligand coordination geometry in Mn(I) hydride complexes [(PPP)(CO)MnH] on their kinetic hydricity.

Octahedral Mn(I) complexes bearing tridentate donor ligands [(LL'L'')(CO)MnX] have recently emerged as major players in catalytic (de)hydrogenation processes. While most of these systems are still based on structurally rigid pincer scaffolds imposing a meridional coordination mode, for some more flexible tridentate ligands a facial arrangement of donor moieties becomes possible. Accordingly, the geometry of the corresponding Mn(I) hydrides [(LL'L'')(CO)MnH] directly involved in the catalytic processes, namely the nature of the donor extremity located in the -position of the hydride (CO and L for - and -configurations, respectively) may influence their hydride transfer ability.

Tuning polymer micelle size and dynamics with solvophobic block structure.

Hypothesis: Micelles formed by copolymers with mixed solvophobic blocks have attracted much attention lately. It is expected that changing the mixed blocks sequence can be used as a tool to influence the micellization behavior in a way that is not equivalent to simply varying the incompatibility parameter for pure diblock-copolymers. Simulations: By using coarse-grained simulations, the micellization behavior of copolymers with twelve types of solvophobic blocks, which differed in the fraction f as well as the sequence of solvophilic units in the solvophobic blocks, was studied.

Selectivity Control in Nitroaldol (Henry) Reaction by Changing the Basic Anion in a Chiral Copper(II) Complex Based on ()-2-Aminomethylpyrrolidine and 3,5-Di--butylsalicylaldehyde.

This article is a continuation of our previous research on the catalytic capability of a chiral copper complex based on commercially available ()-2-aminomethylpyrrolidine and 3,5-di--butylsalicylaldehyde with various counter-anions in the asymmetric Henry reaction. Our findings indicate that depending on the type of base used, chiral nitroalcohols with yields up to 98% and values up to 77%, as well as β-nitrostyrenes with yields up to 88%, can be produced. Additionally, it has been found that the outcome of the reaction and the catalytic properties of copper (II) complexes ()- and ()- are influenced by the structure of the aldehyde used.

What is the key factor affecting the cathodoluminescence intensity of europium complexes?

In order to substitute well-studied but hard-to-deposit inorganic cathodoluminescent (CL) compounds with coordination compounds and organic ligands, it is primarily important to establish CL correlation with photoluminescence and increase CL intensity. In this paper, homo- and mixed-ligand 1,4-terephthalates and naphthalene-2,6-carboxylates of europium were studied, including a novel complex (Eu(nda)(BPhen)(HO)) whose crystal structure was determined. They were found to display luminescence of various intensities under excitation by fast electrons, which is characteristic of Eu.

From mother's milk to structural insights: H-N NMR analysis of Lewis X antigen-bearing oligosaccharides isolated from human milk.

Human milk oligosaccharides (HMOs) are complex unconjugated glycans abundant in breast milk, with vital roles in infant nutrition and health. The structural elucidation of HMOs remains challenging due to their diverse compositions and isomeric complexities. This study presents a novel approach employing H-N NMR correlations to pinpoint and characterize HMOs, LNH, LNnH, and their fucosylated derivatives including those of bearing the Lewis X motif.

Double-Armed 18- and 21-Membered Macrocycles as Potential Chelators for Lead and Bismuth Radiopharmaceuticals.

With increasing clinical applications and interest in targeted alpha therapy, there is growing interest in developing alternative chelating agents for [Pb]Pb and [Bi]Bi that exhibit rapid radiolabeling kinetics and kinetic inertness. Herein we report the synthesis and detailed investigation of diacetate and dipicolinate 18- and 21-membered macrocyclic chelators BADA-18, BADA-21, BADPA-18, and BADPA-21 for the complexation of Pb and Bi ions with potential use in the preparation of radiopharmaceuticals. The formation of mononuclear complexes was established by using ESI-mass spectrometry, and their stability constants were determined by potentiometric titration.

Biological Activity Evaluation of Phenolic Isatin-3-Hydrazones Containing a Quaternary Ammonium Center of Various Structures.

A series of new isatin-3-hydrazones bearing different ammonium fragments was synthesized by a simple and easy work-up reaction of Girard's reagents analogs with 1-(3,5-di--butyl-4-hydroxybenzyl)isatin. All derivatives have been shown to have antioxidant properties. In terms of bactericidal activity against gram-positive bacteria, including methicillin-resistant strains of , the best compounds are , , and , bearing octyl, acetal, and brucine ammonium centers, respectively.

Ultrasound protein-copolymer microbubble library engineering through poly(vinylpyrrolidone-co-acrylic acid) structure.

Hypothesis: While albumin-coated microbubbles are routine contrast agents for ultrasound imaging, their short duration of contrast enhancement limits their use, yet can be improved by incorporating protein-copolymer hybrids into microbubble shells. The incorporation of N-vinyl-2-pyrrolidone and acrylic acid copolymer (P(VP-AA)) has been shown to enhance the performance of bovine serum albumin (BSA)-coated microbubbles. However, the impact of the copolymer structural properties on key microbubble characteristics (i.

Cyano-Fluorosulfonylation of Unactivated Alkenes by Photoredox and Copper Dual Catalysis.

Both fluorosulfonyl and cyano groups are important structural motifs in bioactive molecules. Herein, we report a new difunctionalization reaction of alkenes based on fluorosulfonyl radicals, which allows for the introduction of the fluorosulfonyl and cyano groups into unactivated alkenes in one step. This transformation is enabled by merging photoredox and copper catalysis, featuring visible light catalysis, mild conditions, and good functional group tolerance.

Polymer Brushes Synthesized by the "Grafting-through" Approach: Characterization and Scaling Analysis.

In this study, a combined morphological and scaling analysis of brushes synthesized by the "grafting-through" method was performed, and the possibility of regulation of the thickness was revealed on an example of polyacrylamide brushes. The chemical composition of the surface in the proposed three-step approach was analyzed by photoelectron and infrared spectroscopy. It was shown that the thickness of the dried brush can be tuned in a controlled manner by varying the polymerization temperature.