Affiliated subspaces and infiniteness of von Neumann algebras

We show that the structural properties of von Neumann algebra s are connected with the metric and order theoretic properties of various classes of affiliated subspaces. Among others we show that properly infinite von Neumann algebra s always admit an affiliated subspace for which (1) closed and orthogonally closed affiliated subspaces are different; (2) splitting and quasi‐splitting affiliated subspaces do not coincide. We provide an involved construction showing that concepts of splitting and quasi‐splitting subspaces are non‐equivalent in any GNS representation space arising from a faithful normal state on a Type I factor. We are putting together the theory of quasi‐splitting subspaces developed for inner product spaces on one side and the modular theory of von Neumann algebra s on the other side.     

Synthesis and antiviral activity of novel imidazo[2,1-b]thiazoles coupled with morpholine and thiomorpholines

Herein described the synthesis and antiviral evaluation of a novel series of morpholine and thio-morpholine coupled imidazo[2,1-b]thiazoles. The three-step reaction sequence involving the condensation of 1,3-dichloroacetone with thiourea followed by coupling with morpholine and thiomorpholine and finally cyclization with substituted α-bromoacetophenones yielded the desired imidazothiazoles 7(a–l) . Screening of all the new compounds for their in vitro antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) in MDCK cells, resulted in two potent analogs, 7d (IC₅₀: 1.1 μM, C₅₀: >300 μM, SI = 273) and 7e (IC₅₀: 2.0 μM, C₅₀: >300 μM, SI = 150), with a favorable toxicity profile and are the best anti-influenza hit analogs for further structural optimization.     

A convenient synthetic approach to dioncoquinone B and related compounds

A total synthesis of dioncoquinone B and related compounds, including ancistroquinones B, C and malvon A, is presented. The strategy is based on available reagents and can be used as a preparative synthesis of a number of natural and synthetic biologically active (3-alkyl)-2,7,8-di(tri)methoxy(hydroxy)-1,4-naphthoquinones.     

Helicoidal Patterning of Nanorods with Polymer Ligands

Chiral packing of ligands on the surface of nanoparticles (NPs) is of fundamental and practical importance, as it determines how NPs interact with each other and with the molecular world. Herein, for gold nanorods (NRs) capped with end‐grafted nonchiral polymer ligands, we show a new mechanism of chiral surface patterning. Under poor solvency conditions, a smooth polymer layer segregates into helicoidally organized surface‐pinned micelles (patches). The helicoidal morphology is dictated by the polymer grafting density and the ratio of the polymer ligand length to nanorod radius. Outside this specific parameter space, a range of polymer surface structures was observed, including random, shish‐kebab, and hybrid patches, as well as a smooth polymer layer. We characterize polymer surface morphology by theoretical and experimental state diagrams. The helicoidally organized polymer patches on the NR surface can be used as a template for the helicoidal organization of other NPs, masked synthesis on the NR surface, as well as the exploration of new NP self‐assembly modes.     

Towards DNA Nanomachines for Cancer Treatment: Achieving Selective and Efficient Cleavage of Folded RNA

Despite decades of effort, gene therapy (GT) has failed to deliver clinically significant anticancer treatment, owing in part to low selectivity, low efficiency, and poor accessibility of folded RNA targets. Herein, we propose to solve these common problems of GT agents by using a DNA nanotechnology approach. We designed a deoxyribozyme‐based DNA machine that can i) recognize the sequence of a cancer biomarker with high selectivity, ii) tightly bind a structured fragment of a housekeeping gene mRNA, and iii) cleave it with efficiency greater than that of a traditional DZ‐based cleaving agent. An important advantage of the DNA nanomachine over other gene therapy approaches (antisense, siRNA, and CRISPR/cas) is its ability to cleave a housekeeping gene mRNA after being activated by a cancer marker RNA, which can potentially increase the efficiency of anticancer gene therapy. The DNA machine could become a prototype platform for a new type of anticancer GT agent.     

Arylation Chemistry for Bioconjugation

Bioconjugation chemistry has been used to prepare modified biomolecules with functions beyond what nature intended. Central to these techniques is the development of highly efficient and selective bioconjugation reactions that operate under mild, biomolecule compatible conditions. Methods that form a nucleophile–sp² carbon bond show promise for creating bioconjugates with new modifications, sometimes resulting in molecules with unparalleled functions. Here we outline and review sulfur, nitrogen, selenium, oxygen, and carbon arylative bioconjugation strategies and their applications to modify peptides, proteins, sugars, and nucleic acids     

A novel approach to the quantification of urinary aryl-propionamide-derived SARMs by UHPLC–MS/MS

A simple and sensitive procedure for the quantification of two commonly abused aryl-propionamide-derived selective androgen receptor modulators (SARMs), namely S-4 (GTx-007, andarine) and S-22 (GTx-024, MK-2866, ostarine, enobosarm), has been described. Urine samples were prepared for analysis by means of a dispersive liquid–liquid microextraction using methanol and chloroform as dispersive and extracting solvents, respectively. Factors that might influence the extraction process as well as their optimum conditions were evaluated by Box–Benken and central composite designs. After extraction, the analytes were quantified by UHPLC–MS/MS. The proposed procedure was validated on human urine samples. As a result, for both SARMs the detection limits were observed at 0.05 ng/mL and calibration curves were linear in the concentration range of 0.25–50 ng/mL with the coefficient of determination of 0.998.     

Accurate theoretical prediction of optical properties of BODIPY dyes

Boron-dipyrromethene dyes (BODIPY) are of great interest nowadays mostly due to their valuable optical properties. Nevertheless, no systematic research of the optical property dependence on the structure of dyes has been performed yet. In this work, analysis of the available quantum-chemical methods for BODIPY optical property calculations has been carried out. The accuracy of eight DFT functionals has been studied. The solvation effects upon excitation have been considered within two schemes. The methods that predict the absorption and emission spectra of BODIPY derivatives with high accuracy have been proposed. Using the suggested methods, the influence of nature of substituents and their position in the BODIPY core on the optical spectra of the dyes has been studied. A complex pattern of red- and blue-shifts in optical spectra in dependence of nature and position of substituents has been revealed. The results of this work provide the way for efficient design of BODIPY derivatives with desired optical properties.     

Modeling of the glycine tripeptide cyclization in the Ser65Gly/Tyr66Gly mutant of green fluorescent protein

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Thin-Layer Chromatography of Metal Cations Modified with Amines and Surfactants and the Sorption-Catalytic Detection of Cobalt(II) and Copper(II)

JPC – Journal of Planar Chromatography – Modern TLC - The thin-layer chromatography (TLC) procedures of metal cations, modified with amines and cationic surfactant micelles, followed by...