A curved nanographene, conceptually by insertion of nitrogen into a trapezoidal planar nanographene at the edge was synthesized by π-extension of the nitrogen-doped hexa-peri-hexabenzocoronene. This N-doped nanographene exhibited a π-electronic concave face containing a nonaromatic azepine ring in the middle with a size of 14.0 Å length and 4.
View Article and Find Full Text PDFAstragaloside IV is a significant chemical component derived from the medicinal plant Astragalus membranaceus. Despite the characterization of several glycosyltransferases from A. membranaceus, the complete biosynthetic pathway of astragaloside IV has not been fully elucidated.
View Article and Find Full Text PDFFive previously undescribed protopanaxatriol-type saponins, notoginsenosides Ta-Te (1-5), together with eighteen known triterpenoid saponins (6-23) were isolated from the roots of Panax notoginseng. The structures of new compounds were determined by HRESIMS and NMR spectroscopic analyses and chemical methods. Compounds 1 and 2 were the first examples of ginsenosides featuring a 6-deoxy-β-d-glucose moiety from Panax species.
View Article and Find Full Text PDFAs a common coal-based solid waste, fly ash is widely used in material filling. However, due to the high resistivity of fly ash itself, the antistatic performance of the filling material is poor. Therefore, antistatic composite powder was prepared by coating nano-sized antimony-doped tin oxide (ATO) on the surface of fly ash, and its preparation mechanism was discussed.
View Article and Find Full Text PDFTwenty-two cephalotaxine-type and ten homoerythrina-type alkaloids, including seven previously undescribed ones, were isolated from the twigs and leaves and the seed kernels of . Their structures were established by spectroscopic analysis, single crystal X-ray diffraction, and ECD calculation methods. Cephalofortunine A β--oxide (1) is the first nitrogen-oxidized homoerythrina-type alkaloid.
View Article and Find Full Text PDFTwenty one abietane diterpenes were isolated from Cephalotaxus oliveri Mast. The structures of 7 undescribed diterpenoids, named cephaloliverins A-G, were elucidated via spectroscopic data interpretation and electronic circular dichroism (ECD) analysis. The isolated diterpenoids were evaluated for their cytotoxicity against three kinds of human tumor cell lines (MCF-7, HepG2, and A549).
View Article and Find Full Text PDFThe Cephalotaxus genus is well-known owing to the numerous complex, biologically relevant natural products that can be obtained from its constituent species. The successful identification of various Cephalotaxus alkaloids and natural, structurally diverse cephalotane diterpenoids that exhibit antitumor activities and excellent pharmacological properties has encouraged the discovery of previously undescribed compounds from this genus. The present review summarizes the different strategies for the total synthesis of cephalotane diterpenoids as well as their diverse chemical structures, antitumor activities, structure-activity relationships (SARs), and biosynthetic pathways.
View Article and Find Full Text PDFEight cephalotaxine-type alkaloids (1-8), including two new compounds cephafortunines A and B (1-2), were isolated from the branches and leaves of Cephalotaxus fortunei var. alpina. Their structures were identified by a series of spectroscopic methods (MS, UV, IR, 1D, and 2D NMR) and comparison with the reported data of known analogs.
View Article and Find Full Text PDFCephafortunoids A-D (1-4), four new compounds, together with ten known ones (5-14), were isolated from the branches and leaves of Cephalotaxus fortunei var. alpina. 1 and 2 represent the first examples of Cephalotaxus troponoid diterpenoids featured an intact C skeleton with CH-17 migrating to C-15 and C-13 respectively.
View Article and Find Full Text PDFMetal-phenolic networks (MPNs) have been exploited to be a versatile coating film to fabricate core-shell structure due to their general adherent properties. Herein, gold nanocuboid (GNCB) wrapped by MPNs (GNCB at MPNs) are prepared by a facile encapsulation method for surface-enhanced Raman scattering (SERS) analysis. The MPN coating not only reshapes the electric field distribution around the nanostructures but also allows the substrate to adsorb more analytes, both of which contribute to the superior SERS activity of GNCB at MPNs.
View Article and Find Full Text PDFNanoparticle (NP) exposure might promote hepatic steatosis, but relatively few studies investigated the influence of multi-walled carbon nanotubes (MWCNTs) on lipid accumulation in hepatocytes in vitro. This study investigated lipid accumulation and the possible role of lipophagy (autophagic degradation of lipid droplets) in MWCNT-exposed HepG2 cells. Pristine (XFM19) and carboxylated MWCNTs (XFM21) were internalized, accompanying cytotoxicity, lysosomal destabilization, and intracellular reactive oxygen species (ROS) production.
View Article and Find Full Text PDFUnderstanding the mechanism of nanoparticle (NP) induced toxicity is important for nanotoxicological and nanomedicinal studies. Endoplasmic reticulum (ER) is a crucial organelle involved in proper protein folding. High levels of misfolded proteins in the ER could lead to a condition termed as ER stress, which may ultimately influence the fate of cells and development of human diseases.
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