Radiochromic Hydrogen‐Bonded Organic Frameworks for X‐ray Detection

Par / 12 juin 2021 / Non classé
Radiochromic Hydrogen-Bonded Organic Frameworks for X-ray Detection

Hydrogen bonded organic frameworks (HOFs) were explored as radiochromic materials responsive to X-ray irradiation, opening a new avenue for their application. The HOFs reported here have the same building block yet different radiochromic behaviors: one is sensitive to both X-ray and UV light, while the other one is specifically responsive to X-ray light. These phenomena provide a precious chance to understand the vital factors that account for the detection specificity of radiochromic materials.

Abstract

Porous materials have been investigated as efficient photochromic platforms for detecting hazardous radiation, while the utilization of hydrogen bonded organic frameworks (HOFs) in this field has remained intact. Herein, two HOFs were synthesized through self-assembly of tetratopic viologen ligand and formic acid (PFC-25, PFC-26), as a new class of “all-organic” radiochromic smart material, opening a gate for HOFs in this field. PFC-26 is active upon both X-ray and UV irradiation, while PFC-25 is only active upon X-ray irradiation. The same building block yet different radiochromic behaviors of PFC-25 and PFC-26 allow us to gain a deep mechanistic understanding of the factors that control the detection specificity. Theoretical and experimental studies reveal that the degree of π-conjugation of viologen ligand is highly related to the threshold energy of triggering a charge transfer, therefore being a vital factor for the particularity of radiochromic materials. Thanks to its convenient processibility, nanoparticle size, and UV silence, PFC-25 can be further fabricated into a portable naked-eye sensor for X-ray detection, which shows obvious color change with the merits of high transmittance contrast, good sensitivity (reproducible dose threshold of 3.5 Gy), and excellent stability. The work exhibits the promising practical potentials of HOF materials in photochromic technology.

Wiley: Chemistry – A European Journal: Table of Contents
Authors: Mojtaba Khanpour, Wen‐Zhou Deng, Zhi‐Bin Fang, Yu‐Lin Li, Qi Yin, An‐An Zhang, Farzaneh Rouhani, Ali Morsali, Tian‐Fu Liu
chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.202101061

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Brønsted acid catalyzed synthesis of 2‐aryl‐quinazolinones via cyclization of 2‐aminobenzamide with benzonitriles in PEG

Par / 11 juin 2021 / heterocycles
Brønsted acid catalyzed synthesis of 2-aryl-quinazolinones via cyclization of 2-aminobenzamide with benzonitriles in PEG

Abstract

A simple and efficient Brønsted acid catalyzed synthesis of 2-aryl-quinazolinones via cyclization of 2-aminobenzamides with benzonitrile in PEG under metal and ligand-free condition. All substituted benzonitriles were also well participated with the formation of the corresponding products in moderate to good yields.

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Zwitterion‐Based Hydrogen Sulfide Nanomotors Induce Multiple Acidosis in Tumor Cells by Destroying Tumor Metabolic Symbiosis

Par / 11 juin 2021 / Non classé
Zwitterion-Based Hydrogen Sulfide Nanomotors Induce Multiple Acidosis in Tumor Cells by Destroying Tumor Metabolic Symbiosis

Using the chemical reaction in a tumor environment, L-cysteine can be catalyzed by cystathionine β-synthase in tumor microenvironment to produce hydrogen sulfide (H2S) and L-serine, to construct H2S-driven nanomotor. The nanomotors can move in tumor microenvironment, destroy tumor metabolic symbiosis and inhibit tumor growth specifically.

Abstract

Destruction of tumor metabolism symbiosis is an attractive cancer treatment method which targets tumor cells with little harm to normal cells. Yet, a single intervention strategy and poor penetration of the drug in tumor tissue result in limited effect. Herein, we propose a zero-waste zwitterion-based hydrogen sulfide (H2S)-driven nanomotor based on the basic principle of reaction in human body. When loaded with monocarboxylic acid transporter inhibitor α-cyano-4-hydroxycinnamic acid (α-CHCA), the nanomotor can move in tumor microenvironment and induce multiple acidosis of tumor cells and inhibit tumor growth through the synergistic effect of motion effect, driving force H2S and α-CHCA. Given the good biosafety of the substrate and driving gas of this kind of nanomotor, as well as the limited variety of nanomotors currently available to move in the tumor microenvironment, this kind of nanomotor may provide a competitive candidate for the active drug delivery system of cancer treatment.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Mimi Wan, Zhiyong Liu, Ting Li, Huan Chen, Qi Wang, Tiantian Chen, Yingfang Tao, Chun Mao
onlinelibrary.wiley.com/doi/10.1002/anie.202104304

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Limonin as a Starting Point for the Construction of Compounds with High Scaffold Diversity

Par / 11 juin 2021 / Non classé
Limonin as a Starting Point for the Construction of Compounds with High Scaffold Diversity

Many compound collections used in high-throughput screening are composed of members whose structural complexity is considerably lower than that of natural products. Here the natural product limonin was leveraged to generate 98 architecturally complex compounds with significant scaffold diversity. Phenotypic screening of the collection led to the discovery of novel anticancer compounds.

Abstract

Structurally complex natural products have been a fruitful source for the discovery and development of new drugs. In an effort to construct a compound collection populated by architecturally complex members with unique scaffolds, we have used the natural product limonin as a starting point. Limonin is an abundant triterpenoid natural product and, through alteration of its heptacyclic core ring system using short synthetic sequences, a collection of 98 compounds was created, including multiple members with novel ring systems. The reactions leveraged in the construction of these compounds include novel ring cleavage, rearrangements, and cyclizations, and this work is highlighted by the discovery of a novel B-ring cleavage reaction, a unique B/C-ring rearrangement, an atypical D-ring cyclization, among others. Computational analysis shows that 52 different scaffolds/ring systems were produced during the course of this work, of which 36 are unprecedented. Phenotypic screening and structure–activity relationships identified compounds with activity against a panel of cancer cell lines.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Lucia Furiassi, Emily J. Tonogai, Paul J. Hergenrother
onlinelibrary.wiley.com/doi/10.1002/anie.202104228

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A Vibration‐Induced‐Emission‐Based Fluorescent Chemosensor for the Selective and Visual Recognition of Glucose

Par / 11 juin 2021 / Non classé
A Vibration-Induced-Emission-Based Fluorescent Chemosensor for the Selective and Visual Recognition of Glucose

A novel sugar fluorescent chemosensor which combines a vibrational-induced-emission (VIE)-active DPAC core and two N-methylaminomethylphenylboronic acid moieties can detect glucose within seconds and discriminate between closely related monosaccharides including those commonly found in blood.

Abstract

The development of chemosensors to detect analytes in biologically relevant solutions is a challenging task. We report the synthesis of a fluorescent receptor that combines vibration-induced emission (VIE) and dynamic covalent chemistry for the detection of glucose in aqueous media. We show that the bis-2-(N-methylaminomethyl)phenylboronic acid-decorated N,N′-diphenyl-dihydrodibenzo[a,c]phenazine (DPAC) receptor 1 can detect glucose and discriminate between closely related monosaccharides including those commonly found in blood. Preliminary studies suggest monosaccharides bind to the DPAC-receptor with a 1:1 stoichiometry to produce pseudomacrocyclic complexes, which in turn leads to distinct optical changes in the fluorescent emission of the receptor for each host. Moreover, the complexation-induced change in emission can be detected visually and quantified in a ratiometric way. Our results highlight the potential of VIE-type receptors for the quantitative determination of saccharides in biological samples.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Javier Ramos‐Soriano, Sergio J. Benitez‐Benitez, Anthony P. Davis, M. Carmen Galan
onlinelibrary.wiley.com/doi/10.1002/anie.202103545

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SO2 Capture Using Porous Organic Cages

Par / 11 juin 2021 / Non classé
SO2 Capture Using Porous Organic Cages

Porous organic cages (POCs) were investigated for the first time for the capture of SO2. A tertiary amine cage (6FT-RCC3) demonstrated remarkably high SO2 capture that was perfectly reversible for at least 50 adsorption–desorption cycles.

Abstract

We report the first experimental investigation of porous organic cages (POCs) for the demanding challenge of SO2 capture. Three structurally related N-containing cage molecular materials were studied. An imine-functionalized POC (CC3) showed modest and reversible SO2 capture, while a secondary-amine POC (RCC3) exhibited high but irreversible SO2 capture. A tertiary amine POC (6FT-RCC3) demonstrated very high SO2 capture (13.78 mmol g−1; 16.4 SO2 molecules per cage) combined with excellent reversibility for at least 50 adsorption–desorption cycles. The adsorption behavior was investigated by FTIR spectroscopy, 13C CP-MAS NMR experiments, and computational calculations.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Eva Martínez‐Ahumada, Donglin He, Victoria Berryman, Alfredo López‐Olvera, Magali Hernandez, Vojtech Jancik, Vladimir Martis, Marco A. Vera, Enrique Lima, Douglas J. Parker, Andrew I. Cooper, Ilich A. Ibarra, Ming Liu
onlinelibrary.wiley.com/doi/10.1002/anie.202104555

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Quantitative and Multiplexed Fluorescence Lifetime Imaging of Intercellular Tensile Forces

Par / 11 juin 2021 / Non classé
Quantitative and Multiplexed Fluorescence Lifetime Imaging of Intercellular Tensile Forces

A fluorescence lifetime imaging-based cell membrane-anchored DNA hairpin probe is designed to measure tensile forces at cell–cell junctions. The tension among multiple ligand–receptor pairs can be quantified simultaneously during cellular processes such as the epithelial–mesenchymal transition.

Abstract

Mechanical interactions between cells have been shown to play critical roles in regulating cell signaling and communications. However, the precise measurement of intercellular forces is still quite challenging, especially considering the complex environment at cell–cell junctions. In this study, we report a fluorescence lifetime-based approach to image and quantify intercellular molecular tensions. Using this method, tensile forces among multiple ligand–receptor pairs can be measured simultaneously. We first validated our approach and developed lifetime measurement-based DNA tension probes to image E-cadherin-mediated tension on epithelial cells. These probes were then further applied to quantify the correlations between E-cadherin and N-cadherin tensions during an epithelial–mesenchymal transition process. The modular design of these probes can potentially be used to study the mechanical features of various physiological and pathological processes.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Puspam Keshri, Bin Zhao, Tianfa Xie, Yousef Bagheri, James Chambers, Yubing Sun, Mingxu You
onlinelibrary.wiley.com/doi/10.1002/anie.202103986

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Segmented Flow Processes to Overcome Hurdles of Whole‐Cell Biocatalysis in the Presence of Organic Solvents

Par / 11 juin 2021 / Non classé
Segmented Flow Processes to Overcome Hurdles of Whole-Cell Biocatalysis in the Presence of Organic Solvents

Utilizing tools of segmented flow chemistry enables the conduction of whole-cell biocatalysis efficiently in biphasic media. Exemplified for different biotransformations with an imine reductase, aldoxime dehydratase, allene oxide synthase and cyclase, the power of flow processes is demonstrated, leading to a 3-fold increase of conversion as well as a dramatic simplified work-up and a 1.5-fold higher yield compared to the analogous batch processes.

Abstract

In modern process development, it is imperative to consider biocatalysis, and whole-cell catalysts often represent a favored form of such catalysts. However, the application of whole-cell catalysis in typical organic batch two-phase synthesis often struggles due to mass transfer limitations, emulsion formation, tedious work-up and, thus, low yields. Herein, we demonstrate that utilizing segmented flow tools enables the conduction of whole-cell biocatalysis efficiently in biphasic media. Exemplified for three different biotransformations, the power of such segmented flow processes is shown. For example, a 3-fold increase of conversion from 34 % to >99 % and a dramatic simplified work-up leading to a 1.5-fold higher yield from 44 % to 65 % compared to the analogous batch process was achieved in such a flow process.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Niklas Adebar, Alina Nastke, Jana Löwe, Harald Gröger
onlinelibrary.wiley.com/doi/10.1002/anie.202015887

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Ion Mobility Mass Spectrometry Uncovers Guest‐Induced Distortions in a Supramolecular Organometallic Metallosquare

Par / 11 juin 2021 / Non classé
Ion Mobility Mass Spectrometry Uncovers Guest-Induced Distortions in a Supramolecular Organometallic Metallosquare

We present an ion-mobility mass spectrometry (IM-MS) study on the encapsulation characteristics of a shape-adaptable organometallic metallocage, and demonstrate that IM-MS in combination with DFT calculations constitutes a reliable approach to quantify distortions experienced by the host upon guest encapsulation.

Abstract

The encapsulation of the tetracationic palladium metallosquare with four pyrene-bis-imidazolylidene ligands [1]4+ with a series of organic molecules was studied by Electrospray ionization Travelling Wave Ion-Mobility Mass Spectrometry (ESI TWIM-MS). The method allowed to determine the Collision Cross Sections (CCSs), which were used to assess the size changes experienced by the host upon encapsulation of the guest molecules. When fullerenes were used as guests, the host is expanded ΔCCS 13 Å2 and 23 Å2, for C60 or C70, respectively. The metallorectangle [1]4+ was also used for the encapsulation of a series of polycyclic aromatic hydrocarbons (PAHs) and naphthalenetetracarboxylic diimide (NTCDI), to form complexes of formula [(NTCDI)2(PAH)@1]4+. For these host:guest adducts, the ESI IM-MS studies revealed that [1]4+ is expanded by 47–49 Å2.. The energy-minimized structures of [1]4+, [C60@1]4+, [C70@1]4+, [(NTCDI)2(corannulene)@1]4+ in the gas phase were obtained by DFT calculations.Introduction

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Cristian Vicent, Victor Martinez‐Agramunt, Viraj Gandhi, Carlos Larriba‐Andaluz, Dmitry G. Gusev, Eduardo Peris
onlinelibrary.wiley.com/doi/10.1002/anie.202100914

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A Two‐Pronged Pulmonary Gene Delivery Strategy: A Surface‐Modified Fullerene Nanoparticle and a Hypotonic Vehicle

Par / 11 juin 2021 / Non classé
A Two-Pronged Pulmonary Gene Delivery Strategy: A Surface-Modified Fullerene Nanoparticle and a Hypotonic Vehicle

Tetra(piperazino)fullerene (TPFE)-based nanoparticles (NPs), surface-coated with polyethylene glycol (PEG), were engineered. The PEGylation allows the NPs to avoid interactions with mucin glycoproteins and phagocytic uptake by macrophages. After the NPs access the target lung cells, a hypotonic vehicle solution enhances their endocytosis via the osmotically driven regulatory volume effect, thereby providing highly efficient transgene expression.

Abstract

Inhaled gene therapy poses a unique potential of curing chronic lung diseases, which are currently managed primarily by symptomatic treatments. However, it has been challenging to achieve therapeutically relevant gene transfer efficacy in the lung due to the presence of numerous biological delivery barriers. Here, we introduce a simple approach that overcomes both extracellular and cellular barriers to enhance gene transfer efficacy in the lung in vivo. We endowed tetra(piperazino)fullerene epoxide (TPFE)-based nanoparticles with non-adhesive surface polyethylene glycol (PEG) coatings, thereby enabling the nanoparticles to cross the airway mucus gel layer and avoid phagocytic uptake by alveolar macrophages. In parallel, we utilized a hypotonic vehicle to facilitate endocytic uptake of the PEGylated nanoparticles by lung parenchymal cells via the osmotically driven regulatory volume decrease (RVD) mechanism. We demonstrate that this two-pronged delivery strategy provides safe, wide-spread and high-level transgene expression in the lungs of both healthy mice and mice with chronic lung diseases characterized by reinforced delivery barriers.

Wiley: Angewandte Chemie International Edition: Table of Contents
Authors: Daiqin Chen, Shuai Liu, Dinghao Chen, Jinhao Liu, Jerry Wu, Han Wang, Yun Su, Gijung Kwak, Xinyuan Zuo, Divya Rao, Honggang Cui, Chunying Shu, Jung Soo Suk
onlinelibrary.wiley.com/doi/10.1002/anie.202101732

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Propranolol Activates the Orphan Nuclear Receptor TLX to Counteract Proliferation and Migration of Glioblastoma Cells

Par / 11 juin 2021 / medchem

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Journal of Medicinal Chemistry

Journal of Medicinal Chemistry: Latest Articles (ACS Publications)
Authors: Giuseppe Faudone, Iris Bischoff-Kont, Lea Rachor, Sabine Willems, Rezart Zhubi, Astrid Kaiser, Apirat Chaikuad, Stefan Knapp, Robert Fürst, Jan Heering, and Daniel Merk
feedproxy.google.com/~r/acs/jmcmar/~3/5ziNSorCP3k/acs.jmedchem.1c00733

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Syntheses, Biological Evaluations, and Mechanistic Studies of Benzo[c][1,2,5]oxadiazole Derivatives as Potent PD-L1 Inhibitors with In Vivo Antitumor Activity

Par / 11 juin 2021 / medchem

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Journal of Medicinal Chemistry

Journal of Medicinal Chemistry: Latest Articles (ACS Publications)
Authors: Liu Liu, Zhiying Yao, Shijun Wang, Tao Xie, Guoqing Wu, Honghan Zhang, Pu Zhang, Yaojun Wu, Haoliang Yuan, and Hongbin Sun
feedproxy.google.com/~r/acs/jmcmar/~3/oqW655IROhU/acs.jmedchem.1c00392

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Deep Desulfurization with Record SO2 Adsorption on the Metal–Organic Frameworks

Par / 11 juin 2021 / Non classé

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Journal of the American Chemical Society

Journal of the American Chemical Society: Latest Articles (ACS Publications)
Authors: Fuqiang Chen, Dan Lai, Lidong Guo, Jun Wang, Peixin Zhang, Kaiyi Wu, Zhiguo Zhang, Qiwei Yang, Yiwen Yang, Banglin Chen||, Qilong Ren, and Zongbi Bao
feedproxy.google.com/~r/acs/jacsat/~3/mUVtZVnt4fw/jacs.1c02176

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Excited-State Switching in Rhenium(I) Bipyridyl Complexes with Donor–Donor and Donor–Acceptor Substituents

Par / 11 juin 2021 / Non classé

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Journal of the American Chemical Society

Journal of the American Chemical Society: Latest Articles (ACS Publications)
Authors: Joshua J. Sutton, Dan Preston, Philipp Traber, Johannes Steinmetzer, Xue Wu, Surajit Kayal, Xue-Z. Sun, James D. Crowley, Michael W. George, Stephan Kupfer, and Keith C. Gordon
feedproxy.google.com/~r/acs/jacsat/~3/aRT01PN26SU/jacs.1c02755

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