Synthesis and Biological Evaluation of Chalconesulfonamides: En Route to Proapoptotic Agents with Antiestrogenic Potency.

Breast and other estrogen receptor α-positive cancers tend to develop resistance to existing drugs. Chalcone derivatives possess anticancer activity based on their ability to form covalent bonds with targets acting as Michael acceptors. This study aimed to evaluate the anticancer properties of a series of chalcones (-) with a sulfonamide group attached to the vinyl ketone moiety.

First 4,7-oxygenated 1,10-phenanthroline-2,9-diamides: synthesis, tautomerism and complexation with REE nitrates.

A new family of phenanthroline ligands was prepared. Hydrolysis of 4,7-dihalogenated 1,10-phenanthroline-2,9-diamides in acidic media leads to the formation of the corresponding 4,7-oxygenated derivatives. These ligands can exist in different tautomeric forms.

Energetics of β-lactoglobulin-flavor compounds interactions.

Interaction of bovine β-lactoglobulin (BLG) with several flavor compounds (FC) (2-methylpyrazine, vanillin, 2-acetylpyridine, 2- and 3-acetylthiophene, methyl isoamyl ketone, heptanone, octanone, and nonanone) was studied by high-sensitivity differential scanning calorimetry. The denaturation temperature, enthalpy, and heat capacity increment were determined at different FC concentrations. It was found that the denaturation temperature and heat capacity increment do not depend on the FC concentration, while the denaturation enthalpy decreases linearly with the FC concentration.

Fe(III)-Based Phenylsilsesquioxane/Acetylacetonate Complexes: Synthesis, Cage-like Structure, and High Catalytic Activity.

Unprecedented iron-based silsesquioxane/acetylacetonate complexes were synthesized. The intriguing cage-like structure of compounds is alkaline metal-dependent: the FeLi complex includes condensed Si-silsesquioxane and four acetylacetonate ligands; the FeNa complex exhibits two cyclic Si-silsesquioxane and eight acetylacetonate ligands, while the FeK complex features two cyclic Si-silsesquioxane and six acetylacetonate ligands. The latter case is the very first observation of small trimeric silsesquioxane ligands in the composition of cage-like metallasilsesquioxanes.

Activation of Anthraquinone's Electrophilicity by Light for a Dynamic C-O Bond.

Coupling of photoswitching with dynamic covalent chemistry enables control of the formation and cleavage of covalent bonds by light irradiation. -Aryloxyanthraquinones feature an exclusive ability to switch electrophilicity by interconversion between - and -quinone isomers, which was used for the first time for the implementation of a dynamic C-O bond. Photogenerated -isomers undergo a concerted -Michael addition of phenols to give hitherto unknown 4-hydroxy-10,10-diaryloxyanthracen-9-ones.

Reaction of Picolinamides with Ketones Producing a New Type of Heterocyclic Salts with an Imidazolidin-4-One Ring.

Reactions of picolinamides with 1,3-propanesultone in methanol followed by the treatment with ketones led to a series of previously unknown chemical transformations, yielding first pyridinium salts (-), with a protonated endocyclic nitrogen atom, and then heterocyclic salts (-) containing an imidazolidin-4-one ring. The structures of intermediate and final products were determined by IR and H, C NMR spectroscopy, and X-ray study. The effects of the ketone and alcohol structures on the product yield were studied by quantum-chemical calculations.

An Intramolecular Nitroso-Meerwein-Ponndorf-Verley-Oppenauer Reaction to Access Fused Pyrrolidine Scaffolds.

δ-Hydroxy chloronitroso compounds generated from 1,2-oxazine -oxides undergo a 1,5-hydride transfer related to the Meerwein-Ponndorf-Verley-Oppenauer reaction. Based on the process discovered, a three-step access to fused pyrrolidine scaffolds containing up to four contiguous stereogenic centers starting from simple nitrostyrenes and cycloalkenes or cyclodienes has been developed. The suggested reaction mechanism was confirmed by UV-vis and ATR FT-IR monitoring and DFT calculations.

An insight into the effect of interaction with protein on antibacterial activity of chitosan derivatives.

Antimicrobial activity of chitosan in protein-rich media is of a particular interest for various protein-based drug delivery and other systems. For the first time, bacteriostatic activity of chitosan derivatives in the presence of caseinate sodium (CAS) was studied and discussed. Complexation of chitosan derivatives soluble in acidic (CH and RCH) or alkalescent (RCH) media with CAS was confirmed by fluorescent spectroscopy, turbodimetry, light scattering data and measurement of electrical potentials of CAS/chitosan derivative complexes.

Copper/Ruthenium Relay Catalysis for Stereodivergent Access to δ-Hydroxy α-Amino Acids and Small Peptides.

An atom- and step-economical and redox-neutral cascade reaction enabled by asymmetric bimetallic relay catalysis by merging a ruthenium-catalyzed asymmetric borrowing-hydrogen reaction with copper-catalyzed asymmetric Michael addition has been realized. A variety of highly functionalized 2-amino-5-hydroxyvaleric acid esters or peptides bearing 1,4-non-adjacent stereogenic centers have been prepared in high yields with excellent enantio- and diastereoselectivity. Judicious selection and rational modification of the Ru catalysts with careful tuning of the reaction conditions played a pivotal role in stereoselectivity control as well as attenuating undesired α-epimerization, thus enabling a full complement of all four stereoisomers that were otherwise inaccessible in previous work.

Formation Kinetics and Antimicrobial Activity of Silver Nanoparticle Dispersions Based on N-Reacetylated Oligochitosan Solutions for Biomedical Applications.

The paper presents the results of the synthesis, a detailed kinetics study, and an investigation of the biological activity of silver nanoparticles (AgNPs) in aqueous solutions of N-reacetylated oligochitosan hydrochloride. UV-visible spectrophotometry and dynamic light scattering were employed to control silver ion reduction. The process was observed to follow a pseudo-first-order law.

AgO-Containing Biocidal Interpolyelectrolyte Complexes on Glass Surfaces-Adhesive Properties of the Coatings.

Biocidal coatings are of great interest to the healthcare system. In this work, the biocidal activity of coatings based on a complex biocide containing polymer and inorganic active antibacterial components was studied. Silver oxide was distributed in a matrix of a positively charged interpolyelectrolyte complex (IPEC) of polydiallyldimethylammonium chloride (PDADMAC) and sodium polystyrene sulfonate (PSS) using ultrasonic dispersion, forming nanoparticles with an average size of 5-6 nm.

KuINins as a New Class of HIV-1 Inhibitors That Block Post-Integration DNA Repair.

Integration of HIV-1 genomic cDNA results in the formation of single-strand breaks in cellular DNA, which must be repaired for efficient viral replication. Post-integration DNA repair mainly depends on the formation of the HIV-1 integrase complex with the Ku70 protein, which promotes DNA-PK assembly at sites of integration and its activation. Here, we have developed a first-class inhibitor of the integrase-Ku70 complex formation that inhibits HIV-1 replication in cell culture by acting at the stage of post-integration DNA repair.

Unsymmetrical Pd(II) Pincer Complexes with Benzothiazole and Thiocarbamate Flanking Units: Expedient Solvent-Free Synthesis and Anticancer Potential.

Driven by the growing threat of cancer, many research efforts are directed at developing new chemotherapeutic agents, where the central role is played by transition metal complexes. The proper ligand design serves as a key factor to unlock the anticancer potential of a particular metal center. Following a recent trend, we have prepared unsymmetrical pincer ligands that combine benzothiazole and thiocarbamate donor groups.

Synthesis of Calamitic Fluorinated Mesogens with Complex Crystallization Behavior.

This work presents the synthesis and self-organization of the calamitic fluorinated mesogen, 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-4-iodobutoxy)ethanesulfonic acid, a potential model for perfluorosulfonic acid membranes (PFSA). The compound is derived in three steps from 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-2-iodoethoxy)ethanesulfonyl fluoride, achieving a 78% overall yield. The resulting compound exhibits intricate thermal behavior.

Pyrazolate phenylethynide: direct exchange of the anionic bridging ligand in a cyclic trinuclear silver complex.

Cyclic trinuclear Ag(I) pyrazolate interacts with phenylacetylene forming a mix-ligand complex in which one pyrazolate ligand is changed to phenylethynide. The CC fragment coordinates only to two silver(I) atoms one carbon atom demonstrating unique μ-η σ-coordination with close Ag-C bond lengths and Ag-C-C angles. The complex exhibits blue emission under UV irradiation.

Effects of solvatomorphism, the nature of a chelating ligand synthon and a counterion on the single crystal XRD structure and SMM properties of paramagnetic monocapped cobalt(II) tris-pyrazoloximates.

A series of monocapped cobalt(II) tris-pyrazoloximates was obtained through the template condensation of the corresponding pyrazoloxime, phenylboronic acid and a suitable cobalt(II) halogenide. Comparing 3-acetylpyrazoloxime its methine-containing homolog, the former produced cobalt(II) clathrochelates in substantially higher yields due to the electron donating effect of the methyl substituent, increasing the N-donor ability of its oxime group. Their less N-donor analog with the electron acceptor trifluoromethyl group did not form cobalt(II) complexes of this type.

Electron density-based protocol to recover the interacting quantum atoms components of intermolecular binding energy.

A new approach for obtaining interacting quantum atoms-defined components of binding energy of intermolecular interactions, which bypasses the use of standard six-dimensional integrals and two-particle reduced density matrix (2-RDM) reconstruction, is proposed. To examine this approach, three datasets calculated within the density functional theory framework using the def2-TZVP basis have been explored. The first two, containing 53 weakly bound bimolecular associates and 13 molecular clusters taken from the crystal, were used in protocol refinement, and the third one containing other 20 bimolecular and three cluster systems served as a validation reference.

Triiodide-Based Chair-Like Copper Complex Assembled by Halogen Bonding.

Cocrystallization of the dimeric [Cu(μ-I)(CNXyl)] (Xyl = 2,6-MeCH, ) and polymeric -[Cu(μ-I)(CNCH-2-Cl-6-Me)] () complexes with I at different molar ratios between the reactants resulted in a series of (RNC)CuI-based crystal polyiodides formed along with gradual accumulation of iodine, namely the cocrystals [·I]·[Cu(μ-I)(CNXyl)] followed by the generation of [Cu(μ-I)(CNXyl)]·2I (·2I) or [Cu(μ-I)(CNCH-2-Cl-6-Me)] and then [Cu(μ-I)(CNCH-2-Cl-6-Me)]·/I. The polyiodide ·2I exhibits a novel supramolecular motif─a purely inorganic halogen-bonded Cu(μ-I) core in the chair conformation. The X-ray structure of ·2I featuring I···I contacts was analyzed by a set of theoretical methods and attributed to moderately strong halogen bonding (from -3.

Synthesis of new acyclic chelators H4aPyta and H6aPyha and their complexes with Cu, Ga, Y, and Bi.

In this article, we present the synthesis and characterization of new acyclic pyridine-containing polyaminocarboxylate ligands H4aPyta and H6aPyha, which differ in structural rigidity and the number of chelating groups. Their abilities to form complexes with Cu, Ga, Y, and Bi cations, as well as the stability of the complexes, were evaluated by potentiometric titration method, radiolabeling with the corresponding radionuclides, studies, mass spectrometry, and HPLC. The structures of the resulting complexes were determined using NMR spectroscopy and DFT calculations.

Catalytic Reductive Recyclization of Functionalized Isoxazoline -Oxides to Pyrrolizidine-3-ones.

Pyrrolizidine is among the saturated -heterocyclic scaffolds most frequently found in natural products and pharmaceutically relevant substances. Herein, a strategy for the synthesis of polysubstituted pyrrolizidine-3-ones by catalytic reductive domino-type recyclization of properly functionalized isoxazoline -oxides was developed. The process is diastereoselective, and one diastereomer (out of four possible ones) is predominant in many of the studied cases.

Synthesis of -symmetrical C tetra-adducts reactions of CCl with CH-acids and enol silyl ester.

Here we report the synthesis of novel fullerene derivatives with attached aliphatic residues based on the previously unknown reactions of chlorofullerene CCl with CH-acids and silyl enol ether.

Ca(II) and Yb(II) complexes featuring M(C≡C) structural motif: enforced proximity or genuine η -bonding?

Bis(carbazolide) complexes M[3,6-tBu -1,8-(RC≡C) Carb] (THF) (R=SiMe , n=0, M=Ca, Yb; R=Ph, n=1, M=Ca, Yb; n=0, M=Yb) were synthesized through transamination reaction of M[N(SiMe ) ] (THF) with two molar equivalents of carbazoles. The complexes feature M(η -C≡C) structural motif composed of M(II) ions encapsulated by four acetylene fragments due to atypical for alkaline- and rare-earth metals η -interactions with triple C≡C bond. This interaction is evidenced experimentally by X-ray diffraction, Raman spectroscopy in the solid state and by NMR-spectroscopy in the solution.

Conformational Analysis of 1,5-Diaryl-3-Oxo-1,4-Pentadiene Derivatives: A Nuclear Overhauser Effect Spectroscopy Investigation.

1,5-Diaryl-3-Oxo-1,4-Pentadiene derivatives are intriguing organic compounds with a unique structure featuring a pentadiene core, aryl groups, and a ketone group. This study investigates the influence of fluorine atoms on the conformational features of these derivatives in deuterated chloroform (CDCl) solution. Through nuclear magnetic resonance (NMR) spectroscopy and quantum chemical calculations, we discerned variations in interatomic distances and established predominant conformer proportions.

Synthesis of CF-Containing Spiro-[Indene-Proline] Derivatives via Rh(III)-Catalyzed C-H Activation/Annulation.

An efficient method of accessing new CF-containing spiro-[indene-proline] derivatives has been developed based on a Cp*Rh(III)-catalyzed tandem C-H activation/[3+2]-annulation reaction of 5-aryl-2-(trifluoromethyl)-3,4-dihydro-2-pyrrole-2-carboxylates with alkynes. An important feature of this spiro annulation process is the feasibility of dehydroproline moiety to act as a directing group in the selective activation of the aromatic C-H bond.

Highly Selective CO Hydrogenation to Methanol over Complex In/Co Catalysts: Effect of Polymer Frame.

The growing demand for new energy sources governs the intensive research into CO hydrogenation to methanol, a valuable liquid fuel. Recently, indium-based catalysts have shown promise in this reaction, but they are plagued by shortcomings such as structural instability during the reaction and low selectivity. Here, we report a new strategy of controlling the selectivity and stability of bimetallic magnetically recoverable indium-based catalysts deposited onto a solid support.