Latest ArticlesIn this study, SB216763 and cyclosporine A were identified as anti-influenza A virus (IAV) agents by transcriptome signature reversion (TSR) analysis through deep mining of the cellular transcriptome of human airway and lung cell lines infected with 3 strains of IAV and the chemical perturbations library. A synergistic effect of SB216763 and cyclosporine A against influenza A was disclosed by quantification of the network-based relationship, which was validated in vitro. Along with burgeoning omics approaches, transcriptome-based drug development is flourishing, which provides a novel insight into antivirals discovery with comprehensive cellular transcriptional information of disease and chemical perturbations in multicomponent intervention. This strategy can be applied as a new approach in discovering multitarget antiviral agents from approved drugs, clinical compounds, natural products or other known bioactive compounds.
Targeting RIPK1 is a promising strategy for the treatment or alleviation of acute lung injury (ALI). SZM594, a benzothiazole compound previously developed by our research group, possessed good dual-targeting receptor-interacting protein kinase 1 (RIPK1) and RIPK3 activity and anti-necroptosis activity as well as acceptable in vivo efficacy. In this study, the cyclopropyl moiety of SZM594 was modified based on a structure-based design strategy. The resulting cyclohexanone-containing analogue 41 improved the selectivity toward RIPK1 over RIPK3 and the anti-necroptosis activity was also increased compared with those of SZM594. More importantly, compound 41 could inhibit the tumor necrosis factor-α (TNF-α) expression in lipopolysaccharide (LPS)-induced peritoneal macrophage cell model, and significantly alleviate LPS-induced ALI in a mouse model. This compound could significantly inhibit the expressions of the phosphorylation of RIPK1 and down-stream RIPK3 and mixed lineage kinase domain-like protein (MLKL). Thus, these cyclohexanone-containing benzothiazole analogues represent promising lead structures for the discovery of novel protective agents of ALI.
Plasmodium parasites causing malaria have developed resistance to most of the antimalarials in use, including the artemisinin-based combinations, which are the last line of defense against malaria. This necessitates the discovery of new targets and the development of novel antimalarials. Plasmodium falciparum alanyl aminopeptidase (PfA-M1) and leucyl aminopeptidase (PfA-M17) belong to the M1 and M17 family of metalloproteases respectively and play critical roles in the asexual erythrocytic stage of development. These enzymes have been suggested as potential antimalarial drug targets. Herein we describe the development of peptidomimetic hydroxamates as PfA-M1 and PfA-M17 dual inhibitors. Most of the compounds described in this study display inhibition at sub-micromolar range against the recombinant PfA-M1 and PfA-M17. More importantly, compound 26 not only exhibits potent malarial aminopeptidases inhibitory activities (PfA-M1 Ki = 0.11 ± 0.0002 µmol/L, PfA-M17 Ki = 0.05 ± 0.005 µmol/L), but also possesses remarkable selectivity over the mammalian counterpart (pAPN Ki = 17.24 ± 0.08 µmol/L), which endows 26 with strong inhibition of the malarial parasite growth and negligible cytotoxicity on human cell lines. Crystal structures of PfA-M1 at atomic resolution in complex with four different compounds including compound 26 establish the structural basis for their inhibitory activities. Notably, the terminal ureidobenzyl group of 26 explores the S2′ region where differences between the malarial and mammalian enzymes are apparent, which rationalizes the selectivity of 26. Together, our data provide important insights for the rational and structure-based design of selective and dual inhibitors of malarial aminopeptidases that will likely lead to novel chemotherapeutics for the treatment of malaria.
Arnequinol A (1), featuring an unprecedented 6/6/3 tricyclic carbon skeleton fused with a heptatomic oxo-bridge, together with arnequinone A (2) bearing a highly conjugated methyl-shifting benzogeijerene skeleton, were isolated from Arnebia euchroma. Their structures were elucidated by extensive spectroscopic methods and quantum chemical calculations of the 13C nuclear magnetic resonance (NMR) data and electronic circular dichroism (ECD) spectra. The plausible biosynthetic pathways for 1 and 2 were presented. In in vitro test, compound 2 showed potent neuroprotective activity against serum-deprivation induced PC12 cell damage at a concentration of 10 µmol/L.
DNA-encoded chemical library (DEL) represents an emerging drug discovery technology to construct compound libraries with abundant chemical combinations. While drug-like small molecule DELs facilitate the discovery of binders against targets with defined pockets, macrocyclic DELs harboring extended scaffolds enable targeting of the protein–protein interaction (PPI) interface. We previously demonstrated the design of the first-generation DNA-encoded multiple display based on a constant macrocyclic scaffold, which harvested binders against difficult targets such as tumor necrosis factor-α (TNF-α). Here, we developed a novel strategy which utilized four orthogonal amine-protecting groups on DNA, to explore larger chemical combinations on the same constant macrocyclic scaffold, following the parallel paradigm to mimic the versatile antibody-like multivalent epitope recognition patterns. We successfully integrated these orthogonal protecting groups with acylation and made a mock second-generation DNA-encoded display combination. This work illustrates a strategy to produce larger encoded multiple display on a constant macrocyclic scaffold, which could facilitate potential binder discovery with enhanced affinity to clinically significant PPI targets.
Volatile organic compound (VOC) pollution has a serious impact on human and urgently needs to be controlled through the development of new methods and catalytic materials. Compared with traditional thermal catalytic oxidation, the synergistic photothermocatalysis is regarded as a green and environmentally friendly strategy for organic compound pollutant removal, which can promote spontaneous heating of the surface of catalysts to achieve thermal catalytic reaction conditions via harvesting light irradiation. In this paper, a monolithic photothermocatalyst was synthesized through coating graphene oxide (GO) and MnOx in turn on a commercially available melamine sponge, where the GO mainly acted as a photothermal conversion layer to heat the catalytically active MnOx. This monolithic catalyst presented excellent photo-induced activity for formaldehyde elimination under ambient conditions (~90% degradation ratio in 20 min for ~160 ppm initial concentration formaldehyde), and meanwhile possessed a high catalytic durability for multiple cycles. The kinetic study demonstrated that this photothermocatalytic process followed a pseudo-second-order kinetics. Finally, we proposed a possible formaldehyde degradation pathway based on in situ DRIFTS examination.
Improving the transfer hydrogenation of N-heteroarenes is of key importance for various industrial processes and remains a challenge so far. We reported here a microcapsule-pyrolysis strategy to quasi-continuous synthesis S, N co-doped carbon supported Co single atom catalysts (Co/SNC), which was used for transfer hydrogenation of quinoline with formic acid as the hydrogen donor. Given the unique geometric and electronic properties of the Co single atoms, the excellent catalytic activity, selectivity and stability were observed. Benefiting from the quasi-continuous synthesis method, the as-obtained catalysts provide a reference for the large-scale preparation of single atom catalysts without amplification effect. Highly catalytic performances and quasi-continuous preparation process, demonstrating a new and promising approach to rational design of atomically dispersed catalysts with maximum atomic efficiency in industrial.
Efficient conversion of straw cellulose to chemicals or fuels is an attracting topic today for the utilization of biomass to substitute for fossil resources. The development of catalysts is of vital importance. In this work, a composite catalyst metal-organic frameworks (MOFs) immobilized on three-dimensional reduced graphene oxide (3D-rGO) were synthesized by in situ growth of the MIL-101(Cr) within the 3D-rGO matrix. The supporting of 3D-rGO guaranteed the dispersion and acid site density of MIL-101(Cr). The MIL-101(Cr)@3D-rGO nanocomposite possesses excellent catalytic activity, stability, recyclability and is an idea catalyst for the efficient degradation of straw cellulose into formic acid (FA), acetic acid (AA) and oxalic acid (OA). A maximum FA conversion rates of 95.36% was obtained by using MIL-101(Cr)@3D-rGO(1:1) as catalyst and hydrothermal reaction at mild conditions of 200 ℃ for 1h in alkaline aqueous medium. The MIL-101(Cr)@3D-rGO nanocomposite can be reused with high catalytic activity without any collapse of structure or leaching of chromium.
Adjusting the electronic structure of graphitic carbon nitride (g-C3N4) photocatalyst through π-π conjugation is an effective method to achieve efficient photogenerated carrier separation. One key challenge of π-π conjugation control is to tune the degree of such conjugation without destroying the g-C3N4 structure. Herein we report a conceptual design that achieves a coplanar heterojunction by enhancing the π-π conjugation via the doping of crystalline g-C3N4 using a conjugated double bond ring molecule, 1,3,5-benzenetriol, during calcination process. The selection of the dopant enables the facile creation of a unique coplanar heterojunction which not only retains the pristine network structure of g-C3N4, but remarkably promotes separation and transfer of photogenerated carriers through the enhanced π-conjugated endogenous electric field. As a result, the new g-C3N4 photocatalyst efficiently photocatalytically produces hydrogen from water under visible light irradiation with a high H2 production rate up to 94.94 μmol/h, and a notable external quantum efficiency of 16.4% at 420 nm.
Single metal atoms immobilized on a carbon substrate are of great potential for enhancing the catalytic activities for oxygen reduction and methanol oxidation reactions (ORR/MOR) owing to the maximized atom utilization. Herein, single copper atoms (SCAs) are loaded on macro-porous nitrogen-doped carbon (Cu-NC) derived from zeolitic imidazolate framework-8 (ZIF-8), which are used as catalysts for ORR and Pt-supports for MOR. For ORR, the catalyst marked as Cu-NC-3 exhibits a higher peak potential of 0.87 V (vs. Reversible hydrogen electrode) than that of commercial Pt/C (0.83 V), mainly attributing to that the 3D macro-porous structure of Cu-NC-3 provides adequate space for uniform dispersion of SCAs as the main active species, and smooth diffusion pathways for fast transport of substances (O2, H2O), therefore reducing the overpotential and the intermediate (H2O2) generation to enhance ORR activity. For MOR, Pt-Cu-NC-3 has a higher mass activity of 1217.4 mA/mgPt than that of Pt/C (752.4 mA/mgPt), and its activity maintenance (decline of 27.6%) is also better than Pt/C (decline of 44.0%) after 5000 cyclic voltammetry (CV) cycles. The interactions between SCAs and Pt nanoparticles should facilitate the generation of OH- from water molecules, which can fast eliminate the adsorbed CO to recover the Pt active sites to improve MOR performance. This synthesis strategy affords a new inspiration to prepare single metal atoms loaded on ZIFs-derived macro-structure with diverse activities for ORR/MOR.