Latest ArticlesAn electrochemical sensor (carboxylatopillar[5]arene-coated nitrogen-doped carbon dots, namely CCDs) based on carboxylatopillar[5]arene (CP[5]) functionalized nitrogen-doped carbon dots (N-CDs) has been developed in a facile and economic manner. To improve the performance of this electrochemical sensor in pesticide detection, the optimal solution pH (pH 7) and loading amount of CCDs on the electrode (0.50 mg/mL) have been determined. By virtue of the good conductivity of N-CDs and the molecular recognition property of CP[5], CCDs modified glassy carbon electrode, namely CCDs/GCE, shows excellent anti-interference capability, selectivity, stability, and reproducibility in the sensitive detection of paraquat. The peak currents are proportional to the paraquat concentration (from 0.1 µmol/L to 10 µmol/L) with a detection limit of 6.4 nmol/L (S/N = 3), indicating a great potential in pesticide detection. In comparison with the electrochemical sensors that require expensive metal nanoparticles and complex preparation processes, CCDs/GCE exhibits excellent detection capability of paraquat with lower cost and simpler preparation processes.
Herein, we report a simple and efficient method for the direct installation of chlorodifluoroethyl group onto aromatic molecules of various aromatic amides with a new 2-chloro, 2, 2-difluoroethyl(mesityl)iodonium salt (CDFI). Moreover, the chlorodifluoroethyl compounds could be smoothly converted into difluorovinyl compounds in a one-pot or discrete procedure and regarded as a steady source of difluorovinyl compounds with "HCl-mask".
Biopolymers, including DNA and peptides have been used as excellent self-assembling building blocks for programmable single-component or hybrid materials, due to their controlled molecular interactions. However, combining two assembling principles of DNA-based programmability and peptide-based specific molecular interactions for hybrid structures to microscale has not yet been achieved. In this study, we describe a hybrid microsystem that emerges from the co-assembly of DNA origami structure and short elastin-like polypeptide conjugated oligonucleotides, and initiates liquid-liquid phase separation to generate microdroplets upon heating above the transition temperature. Moreover, the hybrid microdroplets are capable for guest molecule trapping and perform bi-/tri-enzymatic cascades with rate enhancements as open "microreactors". Our programmed assembled DNA-peptide microsystem represents a new combination of DNA nanotechnology and peptide science and opens potential application routes toward life-inspired biomaterials.
1-Substituted 1, 2, 3-triazoles represents 'privileged' structural scaffolds of many clinical pharmaceuticals. However, the traditional methods for their preparation mainly rely on thermal [3 + 2] cycloaddition of potentially dangerous acetylene and azides. Here we report a base-mediated [4 + 1] annulation of azoalkenes generated in situ from readily available difluoroacetaldehyde N-tosylhydrazones (DFHZ-Ts) with amines under relatively mild conditions. This azide- and acetylene-free strategy provides facile access to diverse 1-substituted 1, 2, 3-triazole derivatives in high yield in a regiospecific manner. This transformation has great functional group tolerance and can suit a broad substrate scope. Furthermore, the application of this novel methodology in the gram-scale synthesis of an antibiotic drug PH-027 and in the late-stage derivatization of several bioactive small molecules and clinical drugs demonstrated its generality, practicability and applicability.
An electrochemically promoted decarboxylative borylation reaction is reported. The reaction proceeds under mild conditions in an undivided cell without use of transition metal- or photo-catalysts. The key feature of the reaction is the compatibility of diboron reagents with the electrochemical conditions. This reaction exhibits broad substrate scope, good functional group tolerability, and easy scalability.
Herein, an electrocatalytic protocol for the synthesis of 2, 3-dihydroquinazolin-4(1H)-one has been disclosed. Methanol is activated and utilized as the C1 source to cyclize with 2-aminobenzamides. This cyclization reaction proceeds conveniently (room temperature and air atmosphere) without any homogeneous metal catalysts, external oxidants, or bases. A wide variety of N, N-disubstituted 2, 3-dihydroquinazolin-4(1H)-ones are obtained via this approach. Moreover, when methanol-d4 is used, a deuterated methylene motif is incorporated into the N-heterocycles, providing an efficient approach to the deuterated N-heterocycles.
N6-methyl adenosine (m6A) is an eminent epigenetic mark in mRNAs that affects a broad range of biological functions in diverse species. However, the chemically inert methyl group prevents a direct labeling of this modification for subsequent detection and sequencing. Therefore, most current approaches for the labeling of m6A still have limitations of relying on the utilization of corresponding methyltransferases, which resulted in the lacking of efficiency. Here we present an approach which selectively alkylated the N6-formyl adenosine (f6A), the key intermediate during chemical oxidation of m6A, with an alkyne functionality that can be further labeled with click reactions. This covalent labeling approach will be able to facilitate in the affinity purification, detection and genome-wide profiling studies.
The therapy of non-small lung cancer (NSCLC) is limited by wide metastasis and chemotherapy resistance, herein, we present a new cancer-targeting prodrug PBG with the integration of real-time fluorescence visualization. The potent anticancer drug Gefitinib conjugates a biotin recognition ligand yielding the prodrug PBG via a GSH-activatable disulfide bond linker. Once coupling a near-infrared azo-BODIPY fluorophore into the molecular structure of PBG, we obtain its fluorescent theranostic TBG. The prodrug PBG can sustain Gefitinib release by the high level of GSH in the pathophysiological milieu. We evaluate the drug delivery of the prodrug PBG using fluorescent TBG in PC9 cancer bearing nude mice models, which indicate that TBG can be utilized to monitor the in vivo drug release process. Prodrug PBG can be targeted to accumulate in the cancer lesion with a better and efficaciously therapeutic result compared with the single Gefitinib treatment in cells and in vivo. The fluorescence images also reveal that the targeting accumulation and longitudinal retention of anticancer drug in cancer lesions will contribute to the superior therapeutic effects. The above applications of our new prodrug PBG and its fluorescent theranostic TBG have the potential contribution to the research in biology and the clinical medicine.
Monoamine oxidase A (MAO-A) is a prominent myocardial source of reactive oxygen species (ROS), and its expression and activity are strongly increased in failing hearts. Therefore, accurate evaluation of MAO-A activity in cardiomyocytes is of great importance for understanding its biological functions and early diagnosing the progression of heart failure. However, so far, there is no report on the fluorescent diagnosis of heart failure by a specific probe for MAO-A. In this work, two far-red emissive fluorescent turn-on probes (KXS-M1 and KXS-M2) for the highly selective and sensitive detection of MAO-A were fabricated. Both probes exhibit good response to MAO-A, one of which, KXS-M2, performs better than the other one in terms of a fluorescence increment and sensitivity. Using the pioneering probe KXS-M2, specific fluorescence imaging of MAO-A in glucose-deprived H9c2 cardiac cells, zebrafish and isoprenaline-induced failing heart tissues was achieved, proving that KXS-M2 can serve as a powerful tool for the diagnosis and treatment of heart failure.
Oral drugs have been widely used in clinical therapy, but their developments were severely limited by the side effects of drug exposure as well as the multiple biological barriers. In this study, we constructed a "cluster bomb" oral drug delivery system (DOX@PFeL@L100) with core-shell structure to overcome the complex absorption barriers. The inner core termed as "bomb" that contains a lot of ultra-small diameter Fe3O4 nanoparticles (DOX@PFeL NPs) loaded with doxorubicin (DOX) and modified with l-valine, which can efficiently penetrate the epithelial cells via PePT1 receptor mediated endocytosis. The outer shell of this "cluster bomb" is a layer of pH-sensitive polymer (Eudragit®L100) that can be served as a pH-responsive switch and effectively control the "bomb" release in the intestinal microenvironment to improve the antitumor efficiency by the Fenton like reaction of DOX and Fe2+/Fe3+. This study demonstrates that the "cluster comb" oral drug delivery system can sequentially overcome the multiple biological barriers, providing a safe and effective approach for tumor therapy.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
