We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). ...Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.
•Eight PMFs were isolated from the peel of Citrus reticulata ‘Chachi’ (CRC).•6,7,8,3′,4′-Pentamethoxyflavanone was isolated from the peel of CRC for the first time.•Eight PMFs were quantified by ...HPLC.•SREBPs inhibition, antiproliferative and anti-inflammatory activities of PMFs were investigated.
Citrus polymethoxyflavones (PMFs) have been of increasing interest due to their extensive biological activities. In the present study, a total of eight PMFs were isolated from the peel of Citrus reticulata ‘Chachi’ (CRC). They were individually identified as 5-hydroxy-6,7,8,4′-tetramethoxyflavone (1), 5,6,7,3′,4′-pentamethoxyflavanone (2), 5-hydroxy-6,7,8,3′,4′-pentamethoxyflavone (3), 3,5,6,7,8,3′,4′- heptamethoxyflavone (4), 5,6,7,8,3′,4′-hexamethoxyflavone (5), 5,6,7,8,4′-pentamethoxyflavone (6), 6,7,8,3′,4′-pentamethoxyflavanone (7) and 5,6,7,3′,4′-pentamethoxyflavone (8) by nuclear magnetic resonance and mass spectroscopic analysis. 6,7,8,3′,4′-Pentamethoxyflavanone was isolated from the peel of CRC for the first time. The content of PMFs was firstly quantified in both the peel of CRC and PMF-rich extract by HPLC analysis. Furthermore, the biological activities of PMF compounds were investigated. 3,5,6,7,8,3′,4′-Heptamethoxyflavone demonstrated potent sterol regulatory element-binding proteins inhibition activity and 5-hydroxy-6,7,8,3′,4′-pentamethoxyflavone exhibited strong antiproliferative activity against tumor cell lines. The isolated PMF compounds could also significantly inhibit NO production and the effect varied mainly depending on the number of methoxy groups.
•An efficient Visual Basic for Applications-based background subtraction program was developed in the Microsoft Office.•A novel modified mass defect filter was proposed based on different metabolic ...phase types.•An integrated strategy for chemicalome and metabolome characterization of polymethoxylated flavonoids in Citri Reticulatae Pericarpium was proposed.
Detection of metabolites in complex biological matrixes is a great challenge because of the background noise and endogenous components. Herein, we proposed an integrated strategy that combined background subtraction program and modified mass defect filter (MMDF) data mining in a Microsoft Excel platform for chemicalome and metabolome profiling of the polymethoxylated flavonoids (PMFs) in Citri Reticulatae Pericarpium (CRP). The exogenously-sourced ions were firstly filtered out by the developed Visual Basic for Applications (VBA) program incorporated in the Microsoft Office. The novel MMDF strategy was proposed for detecting both target and untarget constituents and metabolites based on narrow, well-defined mass defect ranges. The approach was validated to be powerful, and potentially useful for the metabolite identification of both single compound and homologous compound mixture. We successfully identified 30 and 31 metabolites from rat biosamples after oral administration of nobiletin and tangeretin, respectively. A total of 56 PMFs compounds were chemically characterized and 125 metabolites were captured. This work demonstrated the feasibility of the integrated approach for reliable characterization of the constituents and metabolites in herbal medicines.
Inhibition of pancreatic lipase is an attractive approach to the treatment of obesity and other metabolic disorders. Naturally occurring phytochemicals are promising sources of lipase inhibitors.
In ...the present study, the anti-lipase activity of Citri Reticulatae Pericarpium (CRP) extracts was firstly evaluated in vitro. Moreover, the dynamic alteration of bioactive flavonoids in CRP collected at different time and its correlation with anti-lipase activities was investigated.
Quantitative analysis of multi-components by a single-marker (QAMS) method was developed and validated for simultaneous determination of six flavonoids including narirutin, hesperidin, didymin, nobiletin, 3,5,6,7,8,3′,4′-heptamethoxyflavone and tangeretin. Anti-lipase activity evaluation and docking studies of the flavonoids was also carried out to screen out the candidate lipase inhibitors.
The QAMS method validation results exhibited that the developed method had desirable specificity, linearity, precision and accuracy. CRP collected in early months contained higher concentrations of bioactive flavonoids, and exhibited more potent anti-lipase activity.
Harvest timing had a significant impact on the amounts of bioactive flavonoids and the anti-lipase activities of CRP extracts. The contents of total flavonoids were positively correlated with the anti-lipase activities of CRP, and polymethoxyflavones played a significant role in the hypolipidemic effect of CRP. Nobiletin might be the most potential lipase inhibitor in CRP.
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Metabolic syndrome (MetS) is intricately linked to dysregulation of gut microbiota and host metabolomes. Here, we first find that a purified citrus polymethoxyflavone-rich extract (PMFE) potently ...ameliorates high-fat diet (HFD)-induced MetS, alleviates gut dysbiosis, and regulates branched-chain amino acid (BCAA) metabolism using 16
rDNA amplicon sequencing and metabolomic profiling. The metabolic protective effects of PMFE are gut microbiota dependent, as demonstrated by antibiotic treatment and fecal microbiome transplantation (FMT). The modulation of gut microbiota altered BCAA levels in the host serum and feces, which were significantly associated with metabolic features and actively responsive to therapeutic interventions with PMFE. Notably, PMFE greatly enriched the commensal bacterium
, and gavage with
reduced BCAA concentrations and alleviated MetS in HFD mice. PMFE may be used as a prebiotic agent to attenuate MetS, and target-specific microbial species may have unique therapeutic promise for metabolic diseases.
We propose a method to search for stellar-mass black hole (BH) candidates with giant companions from spectroscopic observations. Based on the stellar spectra of Large sky Area Multi-Object fiber ...Spectroscopic Telescope (LAMOST) Data Release 6, we obtain a sample of seven giants in binaries with large radial velocity variation ΔVR > 80 km s−1. With the effective temperature, surface gravity, and metallicity provided by LAMOST, and the parallax given by Gaia, we can estimate the mass and radius of the giant, and therefore evaluate the possible mass of the optically invisible star in the binary. We show that the sources in our sample are potential BH candidates, and are worthy of dynamical measurement by further spectroscopic observations. Our method may be particularly valid for the selection of BH candidates in binaries with unknown orbital periods.
Additives are a cost-effective method to improve the performance of the very low profile (HVLP) copper foil coarsened layer. In this paper, the effects of 3,3’-Dithiobis-1-propanesulfonic acid ...disodium salt (SPS), gelatin, and sodium thiazoline dithiopropane sulfonate (SH110) concentration on the morphology, roughness, and peel strength of HVLP copper foil was reported. The results show that SH110 contributes significantly to the reduction of copper foil roughness, improvement of peel strength, and refinement of coarsened layer grains. In addition, the linear scanning voltammetry and AC impedance spectroscopy of the solution were carried out to understand the action mechanism of additives on the copper foil surface. The results demonstrate that SPS promotes the copper deposition process due to the presence of sulfonic acid groups(–SO
3
). The amino group(–NH
2
) of gelatin inhibits copper deposition. SH110 has both promoter (Sodium 3-Mercapto-1-Propane Sulfonate, MPS) and inhibitor (Tetrahydrothiazolidinone, H1) fragments, which achieve synergistic or competitive effects consistent with the composite additive.
Graphical abstract
The traditional Chinese medicine Citri Reticulatae Pericarpium (CRP) was mainly originated from the dried pericarp of Citrus reticulata ‘Chachi’ (Crc), Citrus reticulata ‘Dahongpao’ (Crd), Citrus ...reticulata ‘Unshiu’ (Cru) and Citrus reticulata ‘Tangerina’ (Crt) in China. Since these four cultivars have great similarities in morphology, reliable methods to differentiate CRP cultivars have rarely been reported. To discriminate the differences of these CRP cultivars, herein an efficient and reliable method by combining metabolomics, DNA barcoding and electronic nose was first established. The hierarchical three-step filtering metabolomics analysis based on liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) indicated that 9 species-specific chemical markers including 6 flavanone glycosides and 3 polymethoxyflavones could be considered as marker metabolites for discrimination of the geoherb Crc from other cultivars. A total of 19 single nucleotide polymorphism (SNP) sites were found in nuclear internal transcribed spacer 2 (ITS2) of CRP, and three stable SNP sites (33, 128 and 174) in the ITS2 region can distinguish the four CRP cultivars. The electronic nose coupled with chemometrics could also be used to effectively distinguish Crc from other CRP cultivars. Therefore, our results indicated that the integrated method will be an effective strategy for discrimination of similar herbal medicines.
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•CRP cultivars were differentiated by hierarchical filtering metabolomics analysis.•9 species-specific chemical markers of CRP were discovered.•DNA barcoding analysis of CRP cultivars was investigated.•Electronic nose was developed for discrimination of CRP cultivars.
Cytochrome P450 monooxygenases play a key role in pest resistance to insecticides by detoxification. Four new P450 genes, CYP6AS160, CYP6AS161, CYP4AB73 and CYP4G232 were identified from Solenopsis ...invicta. CYP6AS160 was highly expressed in the abdomen and its expression could be induced significantly with exposure to fipronil, whereas CYP4AB73 was not highly expressed in the abdomen and its expression could not be significantly induced following exposure to fipronil. Expression levels of CYP6AS160 and CYP4AB73 in workers were significantly higher than that in queens. RNA interference-mediated gene silencing by feeding on double-stranded RNA (dsRNA) found that the levels of this transcript decreased (by maximum to 64.6%) when they fed on CYP6AS160-specific dsRNA. Workers fed dsCYP6AS160 had significantly higher mortality after 24 h of exposure to fipronil compared to controls. Workers fed dsCYP6AS160 had reduced total P450 activity of microsomal preparations toward model substrates p-nitroanisole. However, the knockdown of a non-overexpressed P450 gene, CYP4AB73 did not lead to an increase of mortality or a decrease of total P450 activity. The knockdown effects of CYP6AS160 on worker susceptibility to fipronil, combined with our other findings, indicate that CYP6AS160 is responsible for detoxification of fipronil. Feeding insects dsRNA may be a general strategy to trigger RNA interference and may find applications in entomological research and in the control of insect pests in the field.
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