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71.
《中国化学快报》2023,34(2):107421
MicroRNAs (miRNAs) have attracted significant attention in biomedical research and clinical diagnosis. However, due to their inherent characteristics of low abundance and the high complexity of corresponding biological matrices, simultaneous detection of multiple miRNAs at low abundance is still a challenge. In this work, a method coupling exponential amplification reaction (EXPAR) with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is developed for label-free and simultaneous detection of multiple miRNAs. The assay can be performed under isothermal conditions in a single reaction tube, and finished in less than 30 min. It exhibits good quantification ability and with attomolar-level sensitivity for miRNAs detection. It also shows high specificity to distinguish miRNAs at single-nucleotide resolution. We used the method to detect the miRNA-21, let-7a, miRNA-100, and miRNA-125b in samples of spiked human serum and breast cancer cells (i.e., MCF-7, MDA-MB-231 and SK-BR-3). The quantification results were well consistent with the standard real-time fluorescence EXPAR. Consequently, the label-free mass-spectrometric platform could be a potential tool for miRNAs analysis in complex biological samples, and may be used for clinical diagnosis. 相似文献
72.
《中国化学快报》2023,34(5):107805
Photodynamic therapy (PDT) agents may accumulate in skin and cause severe skin cytotoxicity. We report a pro-guest-based supramolecular strategy to selectively activate PDT in the reactive oxygen specie (ROS) overexpressed microenvironment, which is often existing in tumor and inflammatory tissues. PDT agents methylene blue (MB) and basic blue 17 (BB17) are used as model drugs. When encapsulated by acyclic cucurbit[n]uril (CB[n]), the efficacy of PDT agents is significantly inhibited. By contrast, in the presence of ROS (H2O2) and pro-guest, PDT agents are displaced and reactivated to show a dramatically enhanced PDT efficacy in cells. 相似文献
73.
《中国化学快报》2023,34(4):107920
As a glucagon (GCG) receptor (GCGR) and glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) dual agonist, oxyntomodulin (OXM) has been attracting scientific attentions due to its efficacies of suppressing appetite, increasing energy expenditure, and inducing body weight loss in obese humans. Based on the scaffold of native OXM, specific helix-favoring amino acids substitutions and the consequent salt bridge formations were believed to offer enhanced and balanced GCGR/GLP-1R activations through increasing α-helical conformation. Novel OXM analogues are obtained by intramolecular lactam stapling of positions [Glu16 & Lys20] or [Lys17 & Glu21] to further strengthen conformationally constrained stabilization. Even though the lactam staple does not provide additional dual GCGR/GLP-1R activations in vitro, the stapled OXM analogues are firstly reported to have higher or lower anti-PANC-1 cell proliferation activity, meanwhile which has no obvious inhibitory effect on the proliferation of HeLa cells. Therefore, it is speculated that the stapled analogues may have the potential to inhibit the proliferation of specific cancer cell types. Among the stapled peptides as well as their precursors, analogue 6 has the most prominent anti-PANC-1 proliferation activity with the IC50 value of 115.1 μmol/L. Its mechanism of actions including effective signal pathways should be worth further investigations in future. 相似文献
74.
《中国化学快报》2023,34(6):107703
Aqueous zinc-ion batteries (ZIBs) has been regarded as a promising energy storage system for large-scale application due to the advantages of low cost and high safety. However, the growth of Zn dendrite, hydrogen evolution and passivation issues induce the poor electrochemical performance of ZIBs. Herein, a Na3Zr2Si2PO12 (NZSP) protection layer with high ionic conductivity of 2.94 mS/cm on Zn metal anode was fabricated by drop casting approach. The protection layer prevents Zn dendrites formation, hydrogen evolution as well as passivation, and facilitates a fast Zn2+ transport. As a result, the symmetric cells based on NZSP-coated Zn show a stable cycling over 1360 h at 0.5 mA/cm2 with 0.5 mAh/cm2 and 1000 h even at a high current density of 5 mA/cm2 with 2 mAh/cm2. Moreover, the full cells combined with V2O5-based cathode displays high capacities and high rate capability. This work offers a facile and effective approach to stabilizing Zn metal anode for enhanced ZIBs. 相似文献
75.
《中国化学快报》2023,34(1):107589
Three-residue cyclophane-forming enzymes (3-CyFEs) are a group of radical S-adenosylmethionine (SAM) enzymes involved in the biosynthesis of ribosomally synthesized and posttranslationally modified peptides (RiPPs). 3-CyFE catalyzes the crosslinking between an aromatic residue (Ω1) and a non-aromatic residue (X3) in a Ω1-X2-X3 motif to produce a cyclophane ring, a key step in the biosynthesis of the RiPP natural product triceptide. In this study, we perform a genome-wide search for the Xye-type triceptides, showing these RiPPs are likely class-specific and only present in gamma-proteobacteria. The 3-CyFE PauB from Photorhabdus australis exhibits a relaxed substrate specificity on the X3 position, but glycine in this position is not suitable for cyclophane formation. We also reconstituted the activity of PauB in vitro, showing it produces the N-terminal cyclophane firstly, and then the C-terminal ring, whereas the middle cyclophane is produced in the last step. 相似文献
76.
《中国化学快报》2023,34(6):107935
A facile and elegant method for synthesis of novel N–aryl phenothiazine derivatives from 2-phenylindolizines and phenothiazines through direct electrochemical oxidation has been developed. This approach was performed smoothly at room temperature without external oxidant and catalyst. Cyclic voltammetry and in situ FTIR techniques were applied to analyze the cross-coupling process of phenothiazines and 2-phenylindolizines, which helped to select the appropriate reaction potential. Under the optimized conditions, a broad range of substrates were well tolerated, affording the desired products in moderate to excellent isolated yields (up to 91%) with high regioselectivity. Meanwhile, a plausible mechanism involving a radical pathway has been proposed. 相似文献
77.
《中国化学快报》2023,34(9):108156-51
Hydrogen evolution from water electrolysis has become an important reaction for the green energy revolution. Traditional precious metals and their compounds are excellent catalysts for producing hydrogen; however, their high cost limits their large-scale practical application. Therefore, the development of affordable electrocatalysts to replace these precious metals is important. Transition metal phosphides(TMPs) have shown remarkable performance for hydrogen evolution and garnered considerable ... 相似文献
78.
79.
《中国化学快报》2023,34(11):108617
Fluorescent materials that respond to multiple stimuli have broad applications ranging from sensing and bioimaging to information encryption. Herein, we report the design and synthesis of a single-fluorophore-based amphiphile DCSO, which shows temperature-, solvent-, humidity-, and radiation-dependent fluorescence. DCSO consists of a dicyanostilbene (DCS) group as a rigid hydrophobic core with oligo(ethylene glycol) (OEG) chains at both ends as a flexible hydrophilic periphery. The DCS group acts as a highly efficient fluorophore, while the OEG chain endows the molecule with thermo-responsiveness. Fluorescent colors can vary from blue to green to yellow in response to external stimuli. On the basis of light radiation, we demonstrate that this system can be applied to time-dependent information encryption, in which the correct information can only be read at a specific time under irradiation. This work further demonstrates the usefulness and application of single-fluorophore-based luminescent materials with multiple stimuli-responsive functions. 相似文献
80.
《中国化学快报》2023,34(10):108297
A palladium-catalyzed cascade cyclization of allenylethylene carbonates with 1,3-indandiones was developed, providing biologically interesting tetracyclic dihydrocyclopentaindenofuranone derivatives having three contiguous quaternary carbon centers in moderate to high yields with excellent diastereoselectivities. In this reaction, the allene moiety was fully fused into the cyclopentene ring. 相似文献