Seven phenolic compounds, 1 - 7, including a new organic acid gallate, mucic acid 1-ethyl 6-methyl ester 2-O-gallate (7), were isolated from the MeOH extract of the fruits of Phyllanthus emblica L. (Euphorbiaceae). The structures were elucidated on the basis of extensive spectroscopic analysis and comparison with literature data. Upon evaluated for their antioxidant abilities by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. The inhibitory activities against melanogenesis in B16 melanoma cells induced by α-MSH, as well as cytotoxic activities against four human cancer cell lines were also evaluated. All phenolic compounds, 1 - 7, exhibited potent antioxidant abilities (DPPH: IC 5.6 - 12.9 μm; ABTS: 0.87 - 8.43 μm Trolox/μm; FRAP: 1.01 - 5.79 μm Fe /μm, respectively). Besides, 5 - 7, also exhibited moderate inhibitory activities against melanogenesis (80.7 - 86.8% melanin content), even with no or low toxicity to the cells (93.5 - 101.6% cell viability) at a high concentration of 100 μm. Compounds 1 - 3 exhibited cytotoxic activity against one or more cell lines (IC 13.9 - 68.4%), and compound 1 with high tumor selectivity for A549 (SI 3.2).
Chicoric acid is the main phenolic active ingredient in Echinacea purpurea (Asteraceae), best known for its immune‐enhancing ability, as well as used as a herbal medicine. To achieve further utilization of medicinal ingredients from E. purpurea, an efficient preparative separation of chicoric acid was developed based on macroporous adsorption resin chromatography. The separation characteristics of several different typical macroporous adsorption resins were evaluated by adsorption/desorption column experiments, and HPD100 was revealed as the optimal one, which exhibited that the adsorbents fitted well to the pseudo‐second‐order kinetics model and Langmuir isotherm model, and the optimal process parameters were obtained. The breakthrough curves could be predicted and end‐point could be determined early. Besides, the optimal elution conditions of chicoric acid can be achieved using the quality control methods. As a result, the purity of chicoric acid was increased 15.8‐fold (from 4 to 63%) after the treatment with HPD100. The process of the enrichment and separation of chicoric acid is considerate, because of its high efficiency and simple operation. The established separation and purification method of chicoric acid is expected to be valuable for further utilization of E. purpurea according to product application in pharmaceutical fields in the future.
There is a growing interest in the exploitation of agricultural byproducts. This study explored the potential beneficial health effects from the main biowaste, tea seed pomace of Camellia oleifera Abel (Theaceae), produced when tea seed is processed. Eighteen compounds were isolated from the 70% EtOH extract of the seed cake of C. oleifera. Their structures were determined by ESI-MS, H- and C-NMR together with literature data. All fractions and compounds were evaluated for the antioxidant and melanogenesis inhibitory activities. As the result, AcOEt fraction has the best in vitro antioxidant and antimelanogenesis activities, compounds 7 - 12 and 15 showed remarkable antioxidant activity, compounds 4, 6, 8, and 15 - 17 exhibited superior inhibitory activities against melanogenesis. Furthermore, tyrosinase inhibitory activity assay suggested that compound 8 could suppress melanogenesis by inhibiting the expression of tyrosinase.
Diabetes mellitus (DM), characterized by abnormal carbohydrate, lipid, and protein metabolism, is a metabolic disorder caused by shortage of insulin secretion or decreased sensitivity of target cells to insulin. In...
The
pan-cancer detection and precise visualization of tiny tumors
in surgery still face great challenges. As tumors grow aggressively,
hypoxia is a common feature of solid tumors and has supplied a general
way for detecting tumors. Herein, we report a simple aggregation-induced
emission nanoprobe-TPE-4NE-O that can specifically switch on their
fluorescence in the presence of cytochrome P450 reductase, a reductase
which is overexpressed under hypoxia conditions. The probe can selectively
light up the hypoxia cells and has shown enhanced deep tumor penetration
via charge conversion both in vitro and in
vivo. After being modified with FA-DSPE-PEG, higher tumor
uptake can be seen and FA-DSPE/TPE-4NE-O showed specific visualization
to the hypoxia cancer cells. Excitingly, much brighter fluorescence
was accumulated at the tumors in the FA-DSPE/TPE-4NE-O group, even
though the tumor was as small as 2.66 mm. The excellent performance
of FA-DSPE/TPE-4NE-O in detecting tiny tumors has made it possible
for imaging-guided tumor resection. More importantly, the probe exhibited
good biocompatibility with negligible organ damage and eliminated
a hemolysis risk. The simple but promising probe has supplied a new
strategy for pan-cancer detection and tiny tumor visualization, which
have shown great potential in clinical translation.
The Epstein-Barr virus (EBV) infects more than 95% of adults worldwide and is associated with various malignant tumors and immune diseases, imparting a huge disease burden on the human population. Available EBV vaccines are imminent. Prophylactic vaccines can effectively prevent the spread of infection, whereas therapeutic vaccines mainly stimulate cell-mediated immunity and kill infected cells, thus curbing the development of malignant tumors. Nevertheless, there are still no approved EBV vaccines after decades of effort. The complexity of the EBV life cycle, the lack of appropriate animal models, and the limited reports on adjuvant selection and immune responses are gravely impeding progress in EBV vaccines. The soluble gp350 vaccine could reduce the incidence of infectious mononucleosis (IM), which seemed to offer hope, but could not prevent EBV infection. Continuous research and vaccine trials provide deep insights into the structural biology of viruses, the designs for immunogenicity, and the evolving vaccine platforms. Moreover, the new vaccine candidates are expected to achieve further success via combined immunization to elicit both a dual protection of B cells and epithelial cells, and sustainable immunization against infected cells at several phases of infection.
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