Latest ArticlesIt is of great significance to develop effective antibacterial agents and methods to combat drug resistant bacterial infections due to its increasing threaten to human health and the ineffectiveness of antibiotics. Herein, a multifunctional hybrid nano-assembly (M1-Fe NPs) based on conjugated oligomer and ferrous ion was engineered with favorable bactericidal activity for synergetic antibacterial therapy. The chelation of ferrous ion not only enhances the photothermal conversion efficiency of M1 but also endows the nano-assembly with catalytic capability of transferring H2O2 into stronger oxidant hydroxyl radicals (•OH). Meanwhile, the generated heat can further promote the Fenton reaction activity. By generating cytotoxic heat and oxidative •OH, M1-Fe NPs can effectively kill Staphylococcus aureus in vitro and in vivo with the aid of low dosage of H2O2. The work provides a new multifunctional platform for combinational drug resistant antibacterial therapy and even antitumor therapy.
Fluoroalkyl-containing organic compounds have exhibited wide applications in the field of pharmaceuticals, agrochemicals and materials science due to their outstanding properties such as biological activity, metabolic stability, lipophilicity, excellent chemical and thermal stability. Therefore, various synthetic strategies have been developed for the construction of fluoroalkyl-containing compounds, using highly active fluorinating reagents and fluorinated building blocks. Recently, the use of easily available and inexpensive trifluoroacetic anhydride (TFAA) and its anhydride analogues has attracted great attention to access numerous fluoroalkyl-containing compounds through cyclization and coupling reactions. In this review, we summarized the recent advances in the synthesis of fluoroalkylated compounds using fluoroalkyl anhydrides as reagents. This review aims to provide a reference for researchers on how to develop new synthetic straregies of fluorine-containing organic compounds and achieve kilograms or even tons preparation of fluorine-containing organic compounds using fluoroalkyl anhydrides.
The existing industrial ammonia synthesis usually adopts the Haber-Bosch process, which requires harsh conditions of high temperature and high pressure, and consumes high energy. Under this circumstance, photoelectrochemical (PEC) catalysis is regarded as a promising method for N2 reduction reaction (NRR), but bears problems of low efficiency and yield. Thus, exploring active catalysts remains highly desirable. In this work, BiVO4@MXene hybrids have been facilely synthesized by a hydrothermal route. The heterojunctions by the in situ growth of BiVO4 onto two-dimensional (2D) MXene greatly increase the NRR efficiency: under photoelectric conditions, the optimized NH3 yield is 27.25 μg h -1 cm-2, and the Faraday efficiency achieves 17.54% at -0.8 V relative to the reversible hydrogen electrode (RHE), which are higher than most state-of-the-art NRR (photo) electrocatalysts. The mechanism speculation shows the enhanced light absorption range and the heterojunction formation largely promote the separation and the transfer efficiency of photogenerated carriers, thereby improving the PEC catalytic ability. Therefore, this work provides a hybrid route to combine the advantages of photo and electric catalysis for effective artificial nitrogen fixation.
By integrating one strain-many compounds (OSMAC) and LC–MS-based molecular networking strategies, distachydrimanes A–F (1–6), six novel phenylspirodrimane dimers and hybrids representing two types of unprecedented terpenoid-polyketide hybrid skeletons, were isolated from the modified fermented rice substrate of a coral-derived fungus Stachybotrys chartarum. All the structures incorporating their absolute configurations were elucidated based on comprehensive spectroscopic analyses, mainly including HRESIMS and NMR data, single-crystal X-ray diffraction (Cu Kα), and comparison of the experimental electronic circular dichroism (ECD) data. Architecturally, compounds 1–6 represent an unprecedented class of dimeric phenylspirodrimanes with an unexpected C-18–C-23′ linkage, of which compounds 1–3 also feature an unexpected 5-methyl-1, 3-benzenediol moiety via a carbon-carbon linkage. The bioactivity assay demonstrated that compounds 1, 5 and 6 induced cell proliferation inhibition, G0/G1 cell cycle arrest, senescence and mitochondrial-mediated apoptosis in L1210 cells, highlighting their potentials as a new category of anticancer agents.
In recent years, with the emergence of new pollutants, the effective treatment of wastewater has become very important. Persulfate-based advanced oxidation processes have been successfully applied to the treatment of wastewater, such as wastewater containing antibiotics, pharmaceuticals and personal care products, dyes, endocrine-disrupting chemicals, chlorinated organic pollutants, and phenolics, for the degradation of refractory organic contaminants. This paper summarizes the production of sulfate radicals, which can be generated by the activation of persulfate via conventional and emerging approaches. The existing problems of persulfate-based advanced oxidation processes were analyzed in detail, including residual sulfates, coexisting factors (coexisting inorganic anions and natural organic matter), and energy consumption. This paper proposes corresponding possible solutions to the problems mentioned above, and this paper could provide a reference for the application of persulfate-based advanced oxidation processes in actual wastewater treatment.
Amino acids are basic units to construct a protein with the assistance of various interactions. During this building process, steric hindrance derived from amino acid side groups or side chains is a factor that could not be ignored. In this contribution, adsorption behaviors of C-terminal amino acid derivatives with amino acid residues fused in 3, 4, 9, 10-perylenetetracarboxylic dianhydride were investigated by scanning tunneling microscopy (STM) and density functional theory (DFT) calculations at various liquid/solid interfaces. STM results at 1-phenyloctane/HOPG interface show that N, N'-3, 4, 9, 10-perylenedicarboximide (GP) and N, N'-methyl-3, 4, 9, 10-perylenedicarboximide (AP) formed linear and herringbone structures, respectively. The driving force could be attributed to different H-bonding sites induced by steric hindrance at side groups. N, N'-Benzyl-3, 4, 9, 10-perylenedicarboximide (PP) generates both linear and herringbone structures because steric hindrance changes the H-bonding sites between PP molecules, whereas N, N'-isopropyl-3, 4, 9, 10-perylenedicarboximide (LP) failed to be imaged because of strong steric hindrance coming from larger side group. To further investigate the impact of steric hindrance, we utilized octanoic acid (OA) as solvent to capture the adsorption details of LP and PP. We found that OA molecules drag PP and LP molecules in a different direction to generate linear structure, impeding the molecular rotation. The structure–solvent relationship shows that the steric hindrance is brought by the large side group, which makes it easier to recognize OA molecules at the interface. These results demonstrate that steric effect plays a significant role in altering interaction sites of the compounds during the adsorption process at the liquid/solid interface.
Clear cell renal cell carcinoma (ccRCC) is a heterogeneous malignancy with poor prognosis. Methylation of the N6 position of adenosine (m6A), the most common epigenetic modification in both messenger RNAs and noncoding RNAs, has been reported to regulate the initiation and progression of ccRCC. However, whether and how m6A-related long noncoding RNAs (m6ArlncRNAs) signify the progression of ccRCC remain unclear. We found m6ArlncRNAs are effective signatures illustrating immune landscape and risk stratification in ccRCC. We identified two differently expressed m6ArlncRNAs (DEm6ArlncRNAs), AC008870.2 and EMX2OS, as independent risk factors for overall survival of ccRCC patients, by applying stringent variable selection procedure to data from the Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma project. The risk score generated from the DEm6ArlncRNA expression categorizes patients into either high or low-risk groups, between which, enrichment analysis indicated an enrichment in immunerelated pathways. Under different DEm6ArlncRNA transcription pattern, the two risk groups differ in immune cell population composition and expression levels of therapy targeting genes. Nanoparticle is satisfactory strategy to delivering therapeutic drugs. For further clinical translation, we designed a novel nanoparticle delivery system packaged STM2457 (STM@8P4 NPs), which selectively inhibits AC008870.2- correlated m6A writer. STM@8P4 NPs loaded drug successfully with uniform particle size, long-term stability and high release efficiency. STM@8P4 NPs can easily enter ccRCC cells and showed a highly efficient ccRCC killing activity in vitro. Our results therefore indicate that m6ArlncRNAs expression can depict tumor microenvironment, predict prognosis for ccRCC patient and give hint to therapeutic strategies in ccRCC.
A metal-free porphyrin covalent organic framework was employed as the heterogeneous photocatalyst for the synthesis of tetrahydroquinolines under aerobic conditions. With visible light irradiation of a catalytic amount of H2P-Bph-COF at room temperature, various substituted N, N-dimethylanilines and N-aryl maleimides were transformed to tetrahydroquinoline derivatives in moderate to good yields. This was the first example of the synthesis of tetrahydroquinolines via the photocatalytic aerobic annulation reaction employing the metal-free COF as the heterogeneous photocatalyst.
Improving the utilization of excitons has always been an important topic for the development of electroluminescence devices. In this work, we designed and synthesized three red TADF emitters TPA-DBT12, TPA-DBT3 and DTPA-DBT by employing dibenzothioxanthone (DBT) acceptor framework to stabilize the locally excited triplet state to participate in the reverse intersystem crossing (RISC) process. The fast RISC process and singlet radiation decay process gave rise to evidently enhanced exciton utilization. All of the red OLEDs based on these materials showed maximum EQE over 11% and high exciton utilization close to 100%. This work not only extend the acceptor framework for red materials but also provide a new perspective for the design of highly efficient red TADF materials with 100% exciton utilization by managing locally excited triplet state.
Breast cancer is the most prevalent cancer in women, and it was hard to prevent or diagnose at an early stage. Thus, it is imperative to develop advanced therapeutics for effective treatment. Herein, a targeted daunorubicin (DNR) and cytarabine (ara-C) co-delivery system was developed by modifying the ara-C loaded liposomes (LIP-ara-C) with the hyaluronic acid-DNR (HA-DNR) prodrugs. The co-assembled hybrid nanoparticles (HA-DNR/LIP-ara-C HNPs) exhibited good serum and storage stability with an average diameter of approximately 100 nm. By specifically binding to the CD44 receptors that overexpressed on cancer cells, these HNPs could be uptake via endocytosis and accumulate intracellularly, in which an optimized DNR and ara-C combination at a molar ratio of 1:5 could generate enhanced synergistic effects with reduced dose-related toxicity on cancer cells.