Latest ArticlesOxygen-isotopic labelings play important roles in identifying and understanding chemical and biological processes. Direct C=O to C=18O or C=17O conversion in a single step leading to labeled compounds can alleviate synthetic burdens without the need for resynthesis. Here we describe a photocatalytic oxygen-isotopic labeling protocol that can efficiently and selectively install 18O and 17O on carbonyls of ketones and aldehydes via oxygen isotope exchange with oxygen-isotopic waters (H218O or H217O) as the sources of oxygen isotopes, in which light and oxygen-enabled sodium alkanesulfinates catalyzed this process. This strategy was extended to the in-situ formed ketones from the photocatalytic aerobic oxidation of alkyl arenes and secondary alcohols. Furthermore, reduction of the oxygen-isotopically labeled aldehydes with NaBH4 provided the corresponding oxygen-isotopically labeled primary alcohols. We believe that the oxygen-isotopically labeling method will be widely used in chemistry, biology and medicine fields.
Kirsten rat sarcoma viral oncogene homolog (KRAS)–phosphodiesterase-delta (PDEδ) is a promising target for antitumor drug discovery. Herein, highly efficient and environmentally sensitive fluorescent probes of PDEδ (DS-Probes) were rationally designed. As compared with the reported PDEδ probes, DS-Probes showed higher binding affinity and selectivity, which were able to conveniently and efficiently label PDEδ in live cells as well as tumor tissues. Therefore, these fluorescent probes are expected to facilitate PDEδ-based mechanism elucidation, drug discovery and pathologic diagnosis.
Exosomes play significant roles in physiological and tumorigenic processes and it is desirable to visualize and track the exosomes. Herein, a novel amphiphilic fluorescent probe HBT-Exo based on excited-state intramolecular proton transfer (ESIPT) mechanism is reported for exosome-labeling. Its ESIPT characteristics were confirmed by both theory calculation and experimental observation, which enable the probe to show a large Stokes shift as well as near-infrared (NIR) keto-form emission. HBT-Exo displayed excellent biocompatibility and remarkable efficiency for exosome-labeling in gastric cancer cells. Furthermore, the labeled exosomes were successfully applied for the real-time in situ imaging in mouse models.
Efficient and modular synthesis of structurally diverse 1,4-diketones from readily available building blocks represents an essential but challenging task in organic chemistry. Herein, we report a multi-component, regioselective bis-acylation of olefins by merging NHC organocatalysis and photoredox catalysis. With this protocol, a broad range of 1,4-diketones could be rapidly assembled using bench-stable feedstock materials. The robustness of this method was further evaluated by sensitivity screening, and good reproductivity was observed. Moreover, the diketone products could be readily converted into functionalized heterocycles, such as multi-substituted furan, pyrrole, and pyridazine. Mechanistic investigations shed light on the NHC and photoredox dual catalytic radical reaction mechanism.
Flexible electronics technology is considered as a revolutionary technology to unlock the bottleneck of traditional rigid electronics that prevalent for decades, thereby fueling the next-generation electronics. In the past few decades, the research on flexible electronic devices based on organic materials has witnessed rapid development and substantial achievements, and inorganic semiconductors are also now beginning to shine in the field of flexible electronics. As validated by the latest research, some of the inorganic semiconductors, particularly those at low dimension, unexpectedly exhibited excellent mechanical flexibility on top of superior electrical properties. Herein, we bring together a comprehensive analysis on the recently burgeoning low-dimension inorganic semiconductor materials in flexible electronics, including one-dimensional (1D) inorganic semiconductor nanowires (NWs) and two-dimensional (2D) transition metal dichalcogenides (TMDs). The fundamental electrical properties, optical properties, mechanical properties and strain engineering of materials, and their performance in flexible device applications are discussed in detail. We also propose current challenges and predict future development directions including material synthesis and device fabrication and integration.
The high amount of L-lysine can increase the potential risk of cardiovascular disease. Additionally, 2-methoxy benzaldehyde (2-MB) has high toxicity and can easily pollute the environment. In this work, carbon quantum dots (CQDs) can be encapsulated into Eu-BTB (H3BTB = 1,3,5-tri(4-carboxyphenyl)benzene), forming the multi-emission composite material Eu-BTB@CQDs. It has two emissions peaks (617 nm for Eu and 470 nm for CQDs). Eu-BTB@CQDs can be applied as bi-functional ratiometric “off & on” luminescent sensor for L-lysine and 2-MB with high sensitivity and selectivity, the low limit of detection (LOD) for L-lysine is 3.68 µmol/L and for 2-MB is 0.54 µmol/L, respectively. Additionally, Eu-BTB@CQDs can quantitatively discriminate L-lysine in the mixed D- and L-lysine water solutions (five different concentrations ratio of L/D-lysine has been set) makes the chiral detection of L-lysine are more meaningful. On the other hand, Eu-BTB@CQDs also can detect 2-MB over 4-methoxybenzaldehyde (4-MB) with high selectivity. Further the detection of 2-MB and L-lysine in the lake water real samples with the reasonable recovery rate. Finally, the detection mechanisms for L-lysine and 2-MB were also investigated and discussed in detail.
Macrocyclic supramolecular complexes demonstrate the dynamic potential to solve global biomedical challenges, a promising cancer treatment modality. The macrocyclic system is an important heterocyclic system widely present in natural products and synthetic molecules. The unique structural feature of macrocyclic supramolecular complexes with desirable donor & acceptor characteristics is beneficial for readily binding with various enzymes and receptors in biological systems through diverse weak interactions, thereby exhibiting broad bioactivities. Macrocyclic-related research and macrocyclic moleculesbased medicinal chemistry developments have become rapidly developing areas of study. Numerous macrocyclic-based molecules as clinical drugs have been extensively used in the clinic to treat various diseases with high therapeutic potency. This critically analyzed work systematically reviews current developments of macrocyclic supramolecular complexes-based compounds in the range of medicinal chemistry as anticancer, anti-inflammatory, and other therapeutic agents, together with their potential applications in diagnostics and pathology. This review will be helpful for medicinal chemistry researchers to develop new thoughts in the quest for rational designs of more active and less toxic macrocyclic supramolecular complexes-based medicinal drugs, as well as more effective diagnostic agents and pathologic probes.
Lignin and its derivatives hold great potential in developing high performance porous carbon materials for supercapacitors due to the versatile features of high carbon content, abundant multifunctional groups, low cost, and environmental benefits. Unfortunately, their derived porous carbon generally has the features of unfavorable microporous-dominated morphologies and low specific surface area (SSA) attributed from the highly-branched structure of lignin, which are hardly suitable for the supercapacitors with ionic liquid (IL) electrolyte, leading to poor energy density and rate capability. Herein, porous carbon materials with desirable mesoporous contributions from sodium lignosulphonate are designed via a facile template method. Such rich mesoporisity carbon materials not only possess with three-dimensional interconnected network, large SSA, as well as favorable pore size distribution for accelerated ion and electron mass transfer, but also feature low heteroatom content for high electrochemical stability. Consequently, the optimal electrode exhibits a high capacitance of 166 F/g at 0.5 A/g, superior rate performance (59 Wh/kg at 59 kW/kg), as well as impressive cycle life with good capacitance retention of 93.1% in EMIBF4 electrolytes. The present work opens a new avenue to design porous carbon materials with high mesopore properties from lignin for effective compatibility with IL electrolyte in high-performance supercapacitors.
DNAzyme machines play critical roles in the fields of cell imaging, disease diagnosis, and cancer therapy. However, the applications of DNAzyme machines are limited by the nucleases-induced degradation, non-specific binding of proteins, and insufficient provision of cofactors. Herein, protected DNAzyme machines with different cofactor designs (referred to as ProDs) were nanoengineered by the construction of multifunctional metal-phenolic nanoshells to deactivate the interferential proteins, including nucleases and non-specific binding proteins. Moreover, the nanoshells not only facilitate the cellular internalization of ProDs but provide specific metal ions acting as cofactors of the designed DNAzymes. Cellular imaging results demonstrated that ProDs could effectively and simultaneously monitor multiple tumor-related microRNAs in living cells. This facile and rapid strategy that encapsulates DNAzyme machines into the protective metal-phenolic nanoshells is anticipated to extend to a wide range of functional nucleic acids-based biomedical applications.