Latest ArticlesMacrophages play a crucial role in initiating, maintaining, and resolving inflammation through the phenotypic shift, inducing or inhibiting the production of inflammatory cytokines. Therefore, macrophages are potential targets for treating inflammatory diseases. Andrographolide (AND) is a potent anti-inflammatory drug that can reduce pro-inflammatory cytokines and suppress NF-κB /MAPK pathway in activated macrophages. Although AND has many medicinal properties, its lower water solubility and first-pass effect in the liver have hindered its clinical application. In this context, by using a metal phenolic network as a stabilizer, we designed and prepared highly stabilized AND nanocrystals (AND-MPN Ns) with high drug loading capacity to facilitate the clinical application of AND. Our findings showed that AND-MPN Ns could be used to enhance the anti-inflammation in-vitro via macrophage polarization, reducing pro-inflammatory cytokines IL-6 and TNF-α, and suppressing the NF-κB signaling pathway activation. The results demonstrated the potential of AND-MPN Ns to combat inflammatory diseases effectively.
Three eudesmanolide sesquiterpene-phenol hybrids, atramacronoids A−C (1−3), featuring an unusual 6/6/5/5/6 skeleton furnished by forming an unexpected C-8−C-16 linkage, were obtained from the rhizomes of Atractylodes macrocephala. Their structures and absolute configurations were elucidated by spectroscopic data analysis, chemical calculations, combined with X-ray diffractions. The plausible biosynthetic pathways for compounds 1−3 are proposed. Surprisingly, compound 1 exhibited cytotoxicity against SGC-7901 cells by inducing cells apoptosis, which might relate to the promotion of synthesis of neutrophil elastase.
Heteroatom doped porous carbon materials have emerged as essential cathode material for metal-air battery systems in the context of soaring demands for clean energy conversion and storage. Herein, a three-dimensional nitrogen-doped carbon self-supported electrode (TNCSE) is fabricated through thermal treatment and acid activation of raw wood. The resulting TNCSE retains the hierarchical porous architecture of parent raw lumber and holds substantial defect sites and doped N sites in the carbon skeleton. Assembled as a cathode in the rechargeable zinc-air battery, the TNCSE exhibits a superior peak power density of 134.02 mW/cm2 and an energy density of 835.92 mAh/g, significantly exceeding the ones reference commercial 20% Pt/C does. More strikingly, a limited performance decay of 1.47% after an ultra long-period (500 h) cycle is also achieved on the TNCSE. This work could offer a green and cost-save approach for rationally converting biomass into a robust self-supporting cathode material for a rechargeable zinc-air battery.
Oral and maxillofacial diseases are a group of high-incidence disorders that affect people's life quality to a great extent, while the wet and highly movable environment of the related regions brings challenges to traditional therapies. Faced with the obstacles of insufficient adhesive strength and ensuing short drug retention time, conventional oral therapeutic agents often have difficulty in achieving their desired efficacy. Oral and maxillofacial wet-adhesive materials have the advantages of excellent wet environment retention, internal stability, plasticity, and clinical potential, thus have become a significant research direction in the field of oral related disorders healing. In the past decade, the development of oral adhesive materials with good wet adhesion has accelerated based on the chemical molecular interaction, physical interlocking, and biological adhesion mechanisms, including biomimetic-inspired materials, naturally derived polymer–based materials and adhesive electrospun fiber films. These fancy wet-adhesive materials can be used for oral mucosal drug delivery, oral vaccination, wound healing, and bone defects treatments. Despite their numerous novel applications, wet-adhesive materials in stomatology still face unresolved challenges from material and biological aspects. Here, advances in designs of oral and maxillofacial wet-adhesive materials are reviewed in terms of design backgrounds, attachment mechanisms, and common classifications. Recent demonstrations of wet-adhesive materials for oral and maxillofacial region medical applications from drug delivery to multifunctional tissue treatments are presented. To conclude, current challenges and prospects on potential applications of oral and maxillofacial wet-adhesive materials are also briefly discussed.
An aldehyde-reactive probe based on 2-amino benzamidoxime (ABAO) framework was introduced, which can selectively label aldehydes in DNA through intramolecular ring closure under mild aqueous solutions. We screened ABAO derivatives that can undergo a cyclization with the formylated nucleobases to generate a fluorescence nucleoside, and of these derivatives 5-methoxy-ABAO (PMA) emerged as the optimal choice. PMA can sensitively and selectively react with 5fU, 5fC and AP to form fluorogenic dihydroquinazoline derivatives, which also can quantify DNA damages induced by γ-irradiation. PMA-initiated labeling strategy provides great convenience for qualitative and quantitative detection of aldehydes in DNA.
We found compound 12N-p-trifluoromethylbenzenesulfonyl matrinane (1) was a potent anti-diabetic agent. Thirty-five tricyclic matrinic derivatives were synthesized and determined for their stimulatory effects on glucose consumption in L6 myotubes, taking 1 as the lead. In high-fat diet (HFD) and STZ induced diabetic mice, 9a significantly lowers blood glucose, improves glucose tolerance, and especially alleviates diabetic nephropathy and islet damage. Mechanism study indicates that 9a simultaneously targets mitochondrial complex I to increase AMP/ATP ratio, as well as liver kinase B1 (LKB1) and calcium/calmodulin-dependent protein kinase (CaMKK), which synergistically activates AMPKα and then stimulates glucose transporter 4 (GLUT4) membrane translocation and 2-deoxyglucose (2-DG) uptake to exert anti-diabetic efficacy. Therefore, compound 9a with a novel structure is a promising anti-diabetic candidate with the advantage of multiple-target mechanism, worthy of further investigation.
The photocatalyzed synthesis of 9-arylpurines has been developed using 9H-purines and non-activated arenes. This method is highly atom economical using an acridinium photocatalyst induced by visible light under air atmosphere at room temperature. It employs no metal or external oxidant for the synthesis of 9-arylpurine derivatives.
Transition-metal-catalyzed decarboxylative and CH functionalization strategy for the construction of Csp2-Csp2, Csp2-Csp, and Csp2-Csp3 bonds has been extensively studied. However, research surveys of this synthetic strategy for the Csp3-Csp3 bond forming reactions are surprisingly scarce. Herein, we present an efficient approach for the rapid formation of Csp3–Csp3 bond through copper-catalyzed decarboxylative Csp3–H functionalization. The present method should provide a useful access to C3-substituted indole scaffolds with possible biological activities. Mechanistic experiments and DFT calculations supported a dual-Cu(Ⅱ)-catalytic cycle involving rate-determining decarboxylation in an outer-sphere radical pathway and spin-crossover-promoted CC bond formation. This strategy offers a promising synthesis method for the construction of Csp3–Csp3 bond in the field of synthetic and pharmaceutical chemistry and extends the number of still limited copper-catalyzed decarboxylative Csp3–Csp3 bond forming reaction.
For circulating tumor cells (CTCs)-based cancer diagnosis and monitoring, effective enrichment and specific analysis of CTCs present significant challenges. The biomembrane interfaces can enhance the high-affinity interactions between various receptors and ligands in life activities by mediating the rearrangement and positioning of membrane-bound components through its fluidity. Inspired by this, we have constructed a multivalent membrane nano-interface using aptamer-linked liposomes for the efficient capture of CTCs. Furthermore, the subsequent introduction of rolling circle amplification (RCA) reaction has increased the number of aptamers and extended them to the surrounding space to improve the affinity of the membrane nano-interface for CTCs. After CTCs are enriched, alkaline phosphatase overexpressed on the surface of tumor cells is used as endogenous enzyme-mediated signal amplification by catalyzing 4-nitrophenyl phosphate (pNPP) with color change, achieving the analysis of CTCs. Finally, the enrichment and visual analysis of human hepatocellular carcinoma (HepG2) with a detection limit of 10 cells/mL can be obtained by integrating the multivalent membrane nano-interface and endogenous enzyme signal amplification. The detection of the target in the serum proved this method has the potential for further clinical application and provides a potential method for studying the correlation between alkaline phosphatase dimer and cancer progression.