RESUMO
A new type of self-supporting multi-channel Janus carbon fibers with efficient water splitting has been successfully manufactured using a specially designed parallel spinneret through electrospinning technology and subsequent carbonization technique. Every single Janus fiber composes of a half side of Mo2C and the other half side of Ni components as Mo2C, Ni embedded in N-doped multi-channel Janus carbon fibers ([Mo2C/C]//[Ni/C]-NMCFs) for overall water splitting. Under optimized condition, the hydrogen evolution reaction overpotential of [Mo2C/C]//[Ni/C]-NMCFs (62 mV) is just 24 mV higher than 20 wt% Pt/C (38 mV) at a current density of 10 mA cm-2. Furthermore, it achieves current density of 10 mA cm-2 to require an overpotential of 324 mV for oxygen evolution reaction. Additionally, the cell assembled by the identical [Mo2C/C]//[Ni/C]-NMCFs catalyst as both the cathode and anode needs only 1.607 V at a current density of 10 mA cm-2, which is only 0.022 V higher than that of Pt/C-IrO2 electrodes. Moreover, [Mo2C/C]//[Ni/C]-NMCFs catalyst also exhibits a long-term stability. The synergistic effect and unique heterostructure of Mo2C and Ni enhance the catalytic activity.
RESUMO
Liverworts provide valuable ecological services to improve the sustainability of agriculture, encompassing soil health maintenance and natural pest management. Some liverworts have potential applications in medicine and as food additives. Twenty-two novel diterpenoids (anajoerins A-V), of which anajoerins B-G are rearranged labdanes featuring an unprecedented 6/5 fused ring system, were isolated from the Chinese liverwort Anastrophyllum joergensenii Schiffn. The absolute configurations of all compounds were identified based on high-resolution electrospray ionization mass spectroscopy data, NMR spectra, and ECD calculations. Plausible biogenetic pathways for unprecedented rearranged labdanes were proposed. Seven diterpenoids exhibited anti-inflammatory activity by reducing nitric oxide production in LPS-stimulated RAW264.7 murine macrophages in a dose-dependent manner with IC50s between 9.71 and 56.56 µM. All tested compounds showed no cytotoxicity at the tested concentrations. Western blot analyses of NF-κB p65 downregulation showed that anajoerin L could inhibit the NF-κB signaling pathway. Furthermore, anajoerin L also suppressed the secretion of the ConA-induced proinflammatory cytokines IFN-γ, TNF-α, and IL-6.
Assuntos
Diterpenos , Hepatófitas , Animais , Camundongos , NF-kappa B/metabolismo , Hepatófitas/metabolismo , Células RAW 264.7 , Anti-Inflamatórios/farmacologia , Citocinas/metabolismo , China , Lipopolissacarídeos/farmacologia , Óxido Nítrico/metabolismoRESUMO
- Seven previously undescribed ent-eudesmane sesquiterpenoids (1-7), as well as seven known analogs (8-14), were isolated from the Chinese liverwort Chiloscyphus polyanthus var. rivularis. Their structures were established based on comprehensive spectroscopy analysis, electronic circular dichroism calculations, as well as biosynthetic considerations. The cytotoxicity against HepG2 (Human hepatocellular carcinomas) cancer cell line, and antifungal activity against Candida albicans SC5314 of all isolated ent-eudesmane sesquiterpenoids were preliminarily tested, results showed that the tested compounds did not display obvious cytotoxicity and antifungal activities under the tested concentration.