The Front Cover illustrates a chimney made of Sn-modified geopolymer-bricks. Functionalized geopolymers can be applied as hybrid material for construction and as an electrode for CO2 electrolysis to formate. The cover was designed by one of the authors Jürgen Schuster and the designer Verena Stöckl. More information can be found in the Research Article by J. Schuster et al.
Noble-free 3D anode: 3D-printed Ti-6Al-4V electrode was evaluated for its anodic behavior in alkaline solutions with a novel electrochemical approach. According to the ECSA results from voltammetry, 3D Ti-6Al-4V provides 42 times more active surface area than flat plate anodes. It enables effective charge transfer of 911 mA cm−2 from almost non-conductive anodic behavior of a plate structure.
Electrochemical processes use expensive noble metal-based anodes which limit industrial implementation. In this study, a noble-metal-free Ti-6Al-4V anode is introduced in an advanced flow reactor. We demonstrate that the 3D additively manufactured electrode can provide a more projected surface area and facilitate anodic reactions under controlled electrolyte conditions. Alkaline NaOH and KOH electrolytes act as anodic electrolytes that are toxic compounds-free and enable corrosion control. Impedance and voltammetry responses to electrochemical reactions are studied. The electrochemical active surface area of the 4 rods scaffold geometry is 42 times higher than a flat plate anode. Therefore, improved charge transfer is achieved in the flow reactor incorporating the 3D Ti-6Al-4V electrode due to the increased surface area and wettability. The structure of almost non-conductive passivation on a flat plate anode is changed to unstable passivation due to the 3D scaffold structure. This enables effective charge transfer of 911 mA cm−2 at higher potentials up to 5 V for 1.5 m KOH in a non-flow condition. Furthermore, a 1 m KOH solution delays metal ion dissolution from the anode surface by acting as a corrosion-controlling medium. 3D Ti-6Al-4V is likely to be an affordable alternative anode in alkaline environmentally friendly electrochemical applications.
In this review, we survey mainly experimental but also theoretical work, focusing on radiation-induced intra- and inter-molecular transfer of charge, atoms, and energy within biomolecular systems in the gas phase. Building blocks of DNA, proteins, and saccharides, but also antibiotics are considered. The emergence of general processes as well as their timescales and mechanisms are highlighted.
In biological tissues, ionizing radiation interacts with a variety of molecules and the consequences include cell killing and the modification of mechanical properties. Applications of biological radiation action are for instance radiotherapy, sterilization, or the tailoring of biomaterial properties. During the first femtoseconds to milliseconds after the initial radiation action, biomolecular systems typically respond by transfer of charge, atoms, or energy. In the condensed phase, it is usually very difficult to distinguish direct effects from indirect effects. A straightforward solution for this problem is the use of gas-phase techniques, for instance from the field of mass spectrometry. In this review, we survey mainly experimental but also theoretical work, focusing on radiation-induced intra- and inter-molecular transfer of charge, atoms, and energy within biomolecular systems in the gas phase. Building blocks of DNA, proteins, and saccharides, but also antibiotics are considered. The emergence of general processes as well as their timescales and mechanisms are highlighted.
In this work, we have described an efficient protocol for the photoinduced defluorocarboxylation of α-trifluoromethylstyrene using formate as the CO2 radical anion precursor, which successfully yields a wide variety of gem-difluorovinylacetic acids with excellent functional group tolerance.
Herein, we report an efficient protocol in which formate is used as a precursor of the CO2 radical anion for the photoinduced defluorocarboxylation of α-trifluoromethylstyrene. A wide range of gem-difluorovinylacetic acids bearing a variety of functional groups were successfully obtained in the absence of metal catalysts. The synthetic value of this protocol was highlighted by successful gram-scale synthesis and late-stage modification for complex biologically active molecules. This protocol provides a complementary method that extends the range of currently available methodologies for accessing the structurally versatile gem-difluoroalkenes.
The cRGD-functionalized nanoparticles obtained by chiral self-assembly with red emission and AIE characteristics could serve as efficient fluorescent probes for targeting cancer cells.
We report a fluorescent dye TM by incorporating the tetraphenylethylene (TPE) and cholesterol components into perylene bisimides (PBI) derivative. Fluorescence emission spectrum shows that the dye has stable red emission and aggregation-induced emission (AIE) characteristics. The incorporation of cholesterol components triggers TM to show induced chirality through supramolecular self-assembly. The cRGD-functionalized nanoparticles were prepared by encapsulating fluorescent dyes with amphiphilic polymer matrix. The functionalized fluorescent organic nanoparticles exhibit excellent biocompatibility, large Stokes’ shift and good photostability, which make them effective fluorescent probes for targeting cancer cells with high fluorescence contrast.
This work summarizes the advances of photo-responsive nanozyme, of which the catalytic activity can be induced or enhanced using different energy electromagnetic waves (infrared, visible light, ultraviolet and X-rays). It offers light-controlled functions and applications that cannot be achieved by pristine nanozyme.
Since the discovery that Fe3O4 nanoparticle has intrinsic natural peroxidase-like activity by Yan et al in 2007, mimicking native enzymes via nano-engineering (named as nanozyme) pays a new avenue to bypass the fragility and recyclability of natural enzymes and thus expedites the biocatalysis in multidisciplinary applications. In addition, the high programmability and structural stability attributes of nanozyme afford the ease of coupling with electromagnetic waves of different energies, providing great opportunities to construct photo-responsive nanozyme under user-defined electromagnetic waves, which is known as photo-nanozyme. In this concept, we aim to providing a summary of how electromagnetic waves with varying wavelengths can serve as external stimuli to induce or enhance the biocatalytic performance of photo-nanozymes, thereby offering fascinating functions that cannot be achieved by pristine nanozyme.
Challenges in the discovery of selective IspE inhibitors with antibacterial activity and no toxicity: This work sheds light on the molecular properties for balancing enzymatic target and bacterial activities simultaneously as well as new starting points for the development of IspE inhibitors with a predicted new mode of action.
Discovery of novel antibiotics needs multidisciplinary approaches to gain target enzyme and bacterial activities while aiming for selectivity over mammalian cells. Here, we report a multiparameter optimisation of a fragment-like hit that was identified through a structure-based virtual-screening campaign on Escherichia coli IspE crystal structure. Subsequent medicinal-chemistry design resulted in a novel class of E. coli IspE inhibitors, exhibiting activity also against the more pathogenic bacteria Pseudomonas aeruginosa and Acinetobacter baumannii. While cytotoxicity remains a challenge for the series, it provides new insights on the molecular properties for balancing enzymatic target and bacterial activities simultaneously as well as new starting points for the development of IspE inhibitors with a predicted new mode of action.
Two for one: We have established an assay for nucleic acid detection by using the target ssRNA-activated protease from the type III-E CRISPR-Cas system. This assay would allow simultaneous detection of one or two target genes or viruses, which could be further expanded by incorporating more type III-E systems of various species. This assay provides an easily adaptable platform for biological and clinical diagnosis.
RNA-guided protease activity was recently discovered in the type III-E CRISPR-Cas systems (Craspase), providing a novel platform for engineering a protein probe instead of the commonly used nucleic acid probe in nucleic acid detection assays. Here, by adapting a fluorescence readout technique using the affinity- and fluorescent protein dual-tagged Csx30 protein substrate, we have established an assay monitoring Csx30 cleavage by target ssRNA-activated Craspase. Four Craspase-based nucleic acid detection systems for genes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), norovirus, and the influenza virus (IFV) were reconstituted with demonstrated specificity. The assay could reliably detect target ssRNAs at concentrations down to 25 pM, which could be further improved approximately 15 000-fold (ca. 2 fM) by incorporating a recombinase polymerase isothermal preamplification step. Importantly, the species-specific substrate cleavage specificity of Craspase enabled multiplexed diagnosis, as demonstrated by the reconstituted composite systems for simultaneous detection of two genes from the same virus (SARS-CoV-2, spike and nsp12) or two types of viruses (SARS-CoV-2 and IFV). The assay could be further expanded by diversifying the fluorescent tags in the substrate and including Craspase systems from various species, thus potentially providing an easily adaptable platform for clinical diagnosis.
![Synthesis of a N-heterocyclic Olefin-Ligated Pd Complex [(NHO)Pd{[2-(CH3O)C6H4]3P}Cl2] as a Catalyst for Suzuki−Miyaura Coupling](https://onlinelibrary.wiley.com/cms/asset/7a3c2972-2335-4271-a900-464ee0f1943d/ejoc202300801-toc-0001-m.png)
N-heterocyclic olefin (NHO) is known as a highly electron-donative ligand, but its application to metal catalysts has rarely been studied. In this study, a well-defined NHO ligated-Pd catalyst was developed. N-substituents on NHO ligand affected the catalytic performance, and the addition of a phosphine co-ligand, in particular [2-(MeO)C6H4]3P was effective to enhance the activity.
N-heterocyclic olefin (NHO) is known as a highly electron-donative ligand, but its application to metal catalysts has rarely been studied. In this study, we synthesized 2-methyleneimidazolidine ligands equipped with a bicyclic frameworks with the goal of developing a NHO-ligated Pd catalyst. These synthesized [(NHO)PdCl(μ-Cl)]2 complexes had a phosphine co-ligand that proved effective as a catalyst for Suzuki-Miyaura coupling at ambient temperature. By optimizing the N-substituents of NHO ligands and a phosphine co-ligand, we developed a [(NHO)Pd{[2-(CH3O)C6H4]3P}Cl2] complex as a catalyst that shows good catalytic activity.
Newly developed rigid-featured chiral Fu-2NO ligands possesses two pyrroloimidazolone-based N-oxides as non-flat chiral walls, and afforded the opportunity for fine-tuning the ligand's electronic and conformational properties by judicious choice of the substituent in the nonligating nitrogen atom.
To expand the chemical space of chiral N-oxides and chiral furan-containing ligands, herein we designed and synthesized a new class of rigid-featured tertiary amine-derived C2 -symmetric chiral furan-N,N′-dioxide (Fu-2NO) ligands from optically pure l-prolinamides/hydroxylprolinamides in operationally simple two steps and up to 57 % overall yield. The newly developed rigid-featured chiral Fu-2NO ligands possesses two pyrroloimidazolone-based N-oxides as non-flat chiral walls, and afforded the opportunity for fine-tuning the ligand electronic and conformational properties by judicious choice of the substituent in the nonligating nitrogen atom. More importantly, The Fu-2NO ligands can tolerate air and moisture such that no special handling is needed for their storage, and can be applied in the Ni(II)-catalyzed asymmetric Friedel-Crafts alkylation reaction of indole.