Anti-Neuroinflammatory Meroterpenoids from a Chinese Collection of the Brown Alga Sargassum siliquastrum.

Nine new chromane-type meroterpenoids, including the rare nor-meroterpenoid sargasilol A (1) and the eight meroditerpenoids sargasilols B-I (2-9), were isolated from a China Sea collection of the brown alga Sargassum siliquastrum, together with six known analogues (10-15). The structures of the new chromanes were identified by extensive spectroscopic analysis and by comparison with previously reported data. Compounds 1-3 and 6-15 exhibited inhibition against LPS-induced NO production in BV-2 microglial cells, and 1, with a shorter carbon chain, was the most active one. Compound 1 was established as an anti-neuroinflammatory agent through targeting the IKK/IκB/NF-κB signaling pathway. As such, the chromanes from brown algae could provide promising anti-neuroinflammatory lead compounds for further structural modification.

A practical application of front-face synchronous fluorescence spectroscopy to rapid, simultaneous and non-destructive determination of piperine and multiple adulterants in ground black and white pepper (Piper nigrum L.).

Based on the distinct fluorescence of piperine and tryptophan, and their different profiles in pepper and several possible adulterants, front-face synchronous fluorescence spectroscopy (FFSFS) was applied for the fast and non-invasive authentication of ground black pepper adulterated with papaya seed powder and buckwheat flour, and ground white pepper adulterated with whole wheat and maize flours. For either single adulterant or dual adulterants in the range of 10-40% w/w, prediction models were constructed based on the combination of unfolded total synchronous fluorescence spectra and partial least square (PLS) regression, and were validated by both five-fold cross-validation and external validation. The built PLS2 models produced suitable results, with most of the determination coefficients of prediction (Rp2) greater than 0.8, the root mean square error of prediction (RMSEP) < 5% and residual predictive deviation (RPD) greater than 2. The limits of detection (LODs) were 11.1, 5.5, 10.6 and 12.0% for papaya seed powder, buckwheat, whole wheat and maize flours, respectively. Most relative prediction errors for simulated blind samples were within ± 30%. Besides, piperine in ground black and white pepper was also determined with acceptable PLS results.

Antioxidant and Neuroprotective Xenicane Diterpenes from the Brown Alga Dictyota coriacea.

Five new xenicane diterpenes, including three rare nitrogen-containing derivatives, dictyolactams A (1) and B (2) and 9-demethoxy-9-ethoxyjoalin (3), a rare diterpene with a cyclobutanone moiety, named 4-hydroxyisoacetylcoriacenone (4), and 19-O-acetyldictyodiol (5), were isolated from an East China Sea collection of the brown alga Dictyota coriacea, along with 15 known analogues (6-20). The structures of the new diterpenes were elucidated by spectroscopic analyses and theoretical ECD calculations. All compounds had cytoprotective effects against oxidative stress in neuron-like PC12 cells. The antioxidant mechanism of 18-acetoxy-6,7-epoxy-4-hydroxydictyo-19-al (6) was related to the activation of Nrf2/ARE signaling pathway; it also showed significant neuroprotective effects against cerebral ischemia-reperfusion injury (CIRI) in vivo. This study provided xenicane diterpene as a promising lead scaffold for the development of potent neuroprotective agents against CIRI.

Rapid, simultaneous and non-destructive determination of multiple adulterants in Panax notoginseng powder by front-face total synchronous fluorescence spectroscopy.

The authentication of traditional herbal medicines in powder form is of great significance, as they are always of high values but vulnerable to adulteration. Based on the distinct fluorescence of protein tryptophan, phenolic acids and flavonoids, front-face synchronous fluorescence spectroscopy (FFSFS) was applied for the fast and non-invasive authentication of Panax notoginseng powder (PP) adulterated with the powder of rhizoma curcumae (CP), maize flour (MF) and whole wheat flour (WF). For either single or multiple adulterants in the range of 5-40% w/w, prediction models were built based on the combination of unfolded total synchronous fluorescence spectra and partial least square (PLS) regression, and were validated by both five-fold cross-validation and external validation. The constructed PLS2 models simultaneously predicted the contents of multiple adulterants in PP and gave suitable results, with most of the determination coefficients of prediction (Rp2) >0.9, the root mean square error of prediction (RMSEP) no >4% and residual predictive deviation (RPD) >2. The limits of detections (LODs) were 12.0, 9.1 and 7.6% for CP, MF and WF, respectively. All the relative prediction errors for simulated blind samples were between -22% and + 23%. FFSFS offers a novel alternative to the authentication of powdered herbal plants.

Enhanced preservation effects of clove (Syzygium aromaticum) essential oil on the processing of Chinese bacon (preserved meat products) by beta cyclodextrin metal organic frameworks (ß-CD-MOFs).

The applications of clove (Syzygium aromaticum) essential oil (CEO) are limited by instability, low solubility and high volatility. The present study aimed to improve the properties of CEO by microencapsulation with cyclodextrin metal organic frameworks (ß-CD-MOFs) to enhance the preservation effects on Chinese bacon (preserved meat products). The microencapsulated CEO by ß-CD-MOFs (CEO/ß-CD-MOFs) not only did not inhibit the antioxidant activities of CEO, but also showed significant improvements on their ROS scavenging abilities and thermo-/pH-stabilities. The increases of superoxide anion and hydroxyl radical scavenging activities were 20.74% and 12.84%, respectively. In addition, less lipid oxidation, including malondialdehyde (MDA) contents and peroxide values (POV), of Chinese bacon was found after the CEO/ß-CD-MOFs treatment than CEO and synthetic antioxidant (BHT) treatments. These results suggested the enhanced preservation effects of microencapsulated CEO on the processing of Chinese bacon and the great potential of ß-CD-MOFs as carriers for essential oils in food industry applications.

Fluorescence quenching by competitive absorption between solid foods: Rapid and non-destructive determination of maize flour adulterated in turmeric powder.

Fluorescence quenching induced by competitive absorption between different components of solid foods was observed for the first time. By using front-face synchronous fluorescence spectroscopy (FFSFS) and fluorescence titration, competitive absorption between maize flour and turmeric powder was proven to occur between phenolic acids in maize flour and curcumin in turmeric powder. FFSFS was applied for the rapid and non-destructive determination of maize flour adulterated in turmeric powder. Prediction models were constructed by partial least square (PLS) regression based on unfolded total synchronous fluorescence spectra, and were validated by five-fold cross-validation and external validation, with the determination coefficient of prediction (Rp2) greater than 0.95, root mean square error of prediction (RMSEP) < 6%, relative error of prediction (REP) < 15% and residual predictive deviation (RPD) greater than 5. The limit of detection (LOD) of maize flour was approximately 9%. In addition, most relative errors for test samples were from -20% to 20%.

Comparative Analysis of Intracellular and in vitro Antioxidant Activities of Essential Oil From White and Black Pepper (Piper nigrum L.).

Ethnopharmacological Relevance: Pepper essential oils have potential immunomodulatory, anti-tumor, and anti-cancer activities. Pepper exhibits the potential to prevent or attenuate carcinogenesis as therapeutic tools. However, the related mechanism remains unelucidated. Aim of the Study: The present study aims to provide reasonable information for the explanation of the dissimilarity of the essential oils from white (WPEO) and black pepper (BPEO). Materials and Methods: WPEO, BPEO, and their single active component, as well as synthetic antioxidants, were compared by the cell model methods and chemical methods, including intracellular antioxidant activity (CAA), total antioxidant activities (TAA), superoxide radical (SR), hydroxyl radical (HR), DPPH radical (DR) scavenging activities and inhibition ability of lipoprotein lipid peroxidation (ILLP). Results: The median effective concentration (EC50) values (mg/mL) of the WPEO and BPEO of SR, HR, DR, and ILLP were 0.437 and 0.327, 0.486 and 0.204, 7.332 and 6.348, 0.688, and 0.624 mg/mL, respectively. The CAA units of WPEO and BPEO were 50.644 and 54.806, respectively. CAA, DR, and TAA of BPEO were significantly higher than those of WPEO (p < 0.05). The BPEO and WPEO can be differentiated as the former have higher correlations with 3-carene, α-pinene, ß-pinene, and limonene while the latter has a higher caryophyllene correlation. The WPEO and BPEO show a good intracellular scavenging ability of reactive oxygen species in HeLa cells. Conclusion: Generally, pepper oil has stronger activities than single components, indicating that pepper is a broad-spectrum natural antioxidant.

Polyethylene mesh knitted fabrics mulching the soil to mitigate China's haze: A potential source of PBDEs.

The fate of polybrominated diphenyl ethers (PBDEs) from polyethylene mesh knitted fabrics (PMKFs) to mulched soil and nearby plants was studied. PBDEs in the soil sample collected from Tianjin University of Commerce in April 2019 increased significantly after 6 months of PMKF mulching owing to PMKFs as the main input source. The compositional profiles/congener patterns of the PBDEs in the soil and PMKFs became similar after 6 months. High correlations were found between ΣPBDEs in the soil and PMKFs in October 2019, with no significant correlation in April. Plants could take up, accumulate and biotransform PBDEs in contaminated soil. The uptake of BDE-209 by plants was the highest compared with other lesser brominated PBDE congeners, due to its higher log Kow value and molecular weight or size. BDE-47 taken up in the plant was biotransformed via hydroxylation. These results prove that the government's PMKF solution to haze is causing environmental problems in bare soil, i.e., PBDE pollution in both soil and nearby plants. The present study provides important pieces of evidence for government and policymakers, and it is recommended that one environmental problem is not solved by creating another.

Front-face synchronous fluorescence spectroscopy for rapid and non-destructive determination of free capsanthin, the predominant carotenoid in chili (Capsicum annuum L.) powders based on aggregation-induced emission.

Capsanthin is the major natural carotenoid pigment in red chili pepper possessing important bioactivity. Its conventional determination method is high performance liquid chromatography (HPLC) with complex and tedious sample pretreatment. In this study, synchronous front-face fluorescence spectroscopy (FFFS) was applied for the fast and non-invasive detection of free capsanthin in chili powders. Although capsanthin was only weak fluorescent in solution state, it showed strong fluorescence in two separated regions in front-face geometry which could also be clearly observed in chili powders. The mechanisms of these emissions are revealed to be aggregation-induced emission (AIE) and J-aggregate formation (JAF). The free capsanthin in 85 chili powder samples were determined by HPLC as in the range of 0.6-3.0 mg/g. The total synchronous FFFS spectra of these samples were scanned. Simple first-order models were built by partial least square regression (PLSR), and were validated by 5-fold cross-validation and external validation. The coefficients of determination (R2) were higher than 0.9, and the root mean square errors (RMSE) were less than 0.2 mg/g. The relative error of prediction (REP) was 9.9%, and the residual predictive deviation (RPD) was 3.7. The method was applied for the estimation of free capsanthin in several real-world samples with satisfactory analytical results. The average relative error to HPLC reference values was -11.8%.

Improvement of the stabilities and antioxidant activities of polyphenols from the leaves of Chinese star anise (Illicium verum Hook. f.) using ß-cyclodextrin-based metal-organic frameworks.

BACKGROUND: Polyphenols extracted from plants are usually highly unstable and rapidly transformed into various reaction products during food and drug processing, thus limiting their applications. To improve the stability and solubility of polyphenols from the leaves of Chinese star anise (Illicium verum Hook. f.), and hence to expand their application to food and medicine, the extracted anise leaf polyphenols (ALPs) were microencapsulated using ß-cyclodextrin (ß-CD) and cyclodextrin-based metal-organic frameworks (ß-CD-MOFs). RESULTS: The optimum inclusion rate of ALP/ß-CD-MOFs was 97.80% at a core-wall ratio of 1:10. Meanwhile, the stabilities, solubilities and antioxidant activities of the polyphenols before and after inclusion were compared. The results showed both the stabilities and solubilities of ALP/ß-CD-MOFs were significantly improved compared with those of ALPs and ALP/ß-CD, suggesting the potential of ß-CD-MOFs as newer and better carriers than ß-CD for polyphenols in food industry applications. The free radical (including superoxide, hydroxyl and DPPH radicals) scavenging activities were also improved by microencapsulation. Superoxide radical scavenging reaction also showed slow-release property of ALP/ß-CD-MOFs. The formation of the inclusion complex was further confirmed using Fourier transform infrared spectral characterization. CONCLUSIONS: Microencapsulation with ß-CD-MOFs could expand the application scope of ALPs, and it is more effective than encapsulation with ß-CD. This is important for a better understanding and application of this useful traditional Chinese plant. As a new material with high efficiency and edibility, ß-CD-MOFs are not limited to the chemical field, but also have potential in new areas of food, medicine and healthcare products. © 2020 Society of Chemical Industry.

Antioxidant compound screening and chemical composition of sweet ginger (Alpinia coriandriodora D. Fang) essential oil and the mechanism of scavenging radicals.

The chemical components of an edible spice, sweet ginger (Alpinia coriandriodora D. Fang) essential oil (AEO) were identified by an ultra-fast gas chromatography electronic nose (E-nose) and the main components were ß-pinene (27.9%), 1,8-cineole (17.3%), p-cymene (13.5%), camphene (7.3%), myrcene (5.4%), and pseudolimonene (4.3%). The antioxidant activity of each component was evaluated and the mechanisms of scavenging free radical were studied by E-nose combined with chemical methodology. Decanal and α-copaene in AEO showed strong scavenging activities against DPPH radical, and the scavenging rates were over 85%. Decanal had a strong scavenging activity for ABTS radical and the scavenging rate was more than 60%. Similarly, terpinen-4-ol and eugenol had strong scavenging abilities to OH radical and the scavenging rates were more than 50%. Gas chromatography-mass spectrography results showed that it was feasible to identify the chemical components of essential oil by E-nose, and the similarity reached 88.9%. PRACTICAL APPLICATIONS: Many essential oils have antioxidant activities and can be used in functional foods. In the present work, the antioxidant active components in AEO were identified and screened by ultra-fast GC E-nose. We aimed to target the components with strong antioxidant activity quickly and efficiently through the analysis of the reaction process of DPPH, ABTS and OH radicals with a high scavenging rate in a short time. These results indicate that ultra-fast GC E-nose can be used to screen the antioxidant active components in the essential oil.

Antioxidant activity screening and chemical constituents of the essential oil from rosemary by ultra-fast GC electronic nose coupled with chemical methodology.

BACKGROUND: Traditional chemical methods were mainly used to evaluate the total antioxidant activity of essential oils. How to determine the bioactivity of each compound in mixtures is an interesting research topic. Nowadays, an ultra-fast gas chromatography electronic nose (E-nose) has been gradually used in the detection of volatile compounds, but the screening of the active components of essential oils has not been reported. E-nose coupled with chemical methodology was established using the essential oil from rosemary (EOR) as a specific application example. The proposed method can both identify the chemical constituents of EOR and quickly screen the antioxidant by comparing the change of chromatographic peak area of every component in EOR before and after reaction with free radicals. RESULTS: Among all chemical constituents in EOR, verbenone, eucalyptol and o-cymene showed the strongest scavenging abilities in 1,1'-diphenyl-2-picrylhydrazine (DPPH·), 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulphonate) (ABTS·+ ) and hydroxyl (·OH) radicals, respectively, with scavenging rates of 67.9%, 39.5%, and 69.9%. The reliability and feasibility of using E-nose to identify chemical constituents of EOR were verified by gas chromatography-tandem mass spectrometry (GC-MS/MS). The GC-MS/MS results showed that the main components of EOR were α-pinene (422.2 µg g-1 ), p-cymene (208.4 µg g-1 ), camphor (203.5 µg g-1 ), verbenone (160.2 µg g-1 ), and eucalyptol (129.1 µg g-1 ). CONCLUSIONS: The E-nose methods can be used as a complementary method to traditional spectrophotometric techniques. Furthermore, this study will be of great significance for the rapid screening of antioxidant active components in essential oils from natural products. © 2020 Society of Chemical Industry.

Facile and Modular Pipeline for Protein-Specific Antibody Customization.

Antibodies are fundamental tools for basic science; however, high-quality antibodies suitable for multiple experimental applications are often inaccessible to research laboratories. To this end, a modular and low-cost pipeline for small-scale antibody customization is developed. First, soluble antigens are designed according to the secondary structure of a desired protein. Then, the antigens are efficiently displayed on a modular nanoplatform by intein-mediated trans-splicing (TS) that enables elicitation of high titers of protein-specific antibodies. After that, target antibodies are obtained by a modular HaloLink resin platform with antigens as the ligand that is devised by intein-mediated TS. Finally, purified antibodies show excellent properties in immunofluorescence, immunoprecipitation, and western blotting assays. Overall, these results suggest that the proposed pipeline is amenable to the generation of high-quality, research-grade antibodies and to aid in protein functional studies.

One pot synthesis of water-soluble quercetin derived multifunctional nanoparticles with photothermal and antioxidation capabilities.

As a member of flavonoids, the application of quercetin has been mainly focused on antioxidation study. Fabrication of multifunctional nanoplatforms with quercetin is limited. In the present study, water-soluble quercetin derived nanoparticles (QFNPs) were fabricated through the one pot synthesis strategy with Fe3+, quercetin and poly (vinyl pyrrolidone) (PVP). The raw materials were dissolved in absolute ethanol and the mixed together. After stirring at room temperature for 6 h, the QFNPs could be simply harvested by centrifugation without the need of time-consuming dialysis procedure. Due to the protective effect of PVP, the synthesized nanoparticles could be well dispersed in water with the hydrodynamic size about 23 nm. DPPH free radical scavenging capacity assay showed QFNPs could act as efficient antioxidant. Besides antioxidation activity, the QFNPs also exhibited good photothermal capacity. Temperature stability result suggested the good stability of QFNPs between 35 and 95 °C. MTT and hemolysis assay showed the good biocompatibility of QFNPs. What's more, the QFNPs showed good cellular antioxidation activity and efficient photothermal killing effect to cancer cells (4T1 cells). The QFNPs could be promising nanoplatform for biomedical application.

Antioxidant activity evaluation of rosemary ethanol extract and their cellular antioxidant activity toward HeLa cells.

Rosemary ethanol extract (REE) from Rosmarinus officinalis was identified by LC-ESI-MS/MS and 12 compounds were found. Among them, rosmarinic acid (389.78 µg/mg in REE), luteolin-3'-O-glucuronide (325.58 µg/mg), luteolin-5-O-glucuronide (120.92 µg/mg), and geniposide (120.83 µg/mg) are the major components. The antioxidant activity evaluation of REE by off-line HPLC methods indicated that among the 12 compounds, rosmarinic acid had the strongest scavenging activities in both DPPH· and ·OH. The cytotoxicity experiment showed that REE with the concentration ranges from 1 to 100 µg/ml did not significantly affect the cell viability of HeLa, while inhibitory rate reduced to 62.3% when the concentration was increased to 1,000 µg/ml. The results of intracellular antioxidation assay showed that the ability of REE in reducing the reactive oxygen species (ROS) in HeLa cells was higher than rosmanol, and lower than rosmarinic acid without cell toxicity. PRACTICAL APPLICATIONS: Plant polyphenols are essential components of functional foods, due to their antioxidant and enzyme inhibition activities. This paper is the first study about the quantification of antioxidant compounds, antioxidant activity evaluation, and their cellular antioxidant activity of polyphenols extract from R. officinalis toward HeLa cells. We aimed to elucidate the chemical composition and recognition of antioxidant components with DPPH and OH free radicals scavenging activity. In addition, the polyphenols dose-response correlations with cellular antioxidant activity were also determined. These results indicated that off-line HPLC method with DPPH and OH free radicals as markers is available for screening antioxidant activity of polyphenols from the mixture.

Synchronous front-face fluorescence spectroscopy for authentication of the adulteration of edible vegetable oil with refined used frying oil.

Synchronous front-face fluorescence spectroscopy has been developed for the discrimination of used frying oil (UFO) from edible vegetable oil (EVO), the estimation of the using time of UFO, and the determination of the adulteration of EVO with UFO. Both the heating time of laboratory prepared UFO and the adulteration of EVO with UFO could be determined by partial least squares regression (PLSR). To simulate the EVO adulteration with UFO, for each kind of oil, fifty adulterated samples at the adulterant amounts range of 1-50% were prepared. PLSR was then adopted to build the model and both full (leave-one-out) cross-validation and external validation were performed to evaluate the predictive ability. Under the optimum condition, the plots of observed versus predicted values exhibited high linearity (R(2)>0.96). The root mean square error of cross-validation (RMSECV) and root mean square error of prediction (RMSEP) were both lower than 3%.

Ultrasonic assisted preparation of lanthanide-oleate complexes for the synthesis of multifunctional monodisperse upconversion nanoparticles for multimodal imaging.

The synthesis of multifunctional monodisperse upconversion nanoparticles (UCNPs) of high quality is highly desired for bioimaging. Lanthanide-oleate complexes are excellent precursors for the synthesis of high quality UCNPs with controllable size and shape. In this work, lanthanide-oleate complexes were prepared by an ultrasonic assisted procedure, and used as precursors for further synthesis of multifunctional monodisperse NaYF4:59%Yb(3+),0.5% Tm(3+)@NaYF4:20%Gd(3+) nanoparticles without the need for further purification. Heavy doping of Yb(3+) in the core and incorporation of Gd(3+) in the shell made the UCNPs promising for upconversion luminescence (UCL), magnetic resonance (MR) and computed tomography (CT) multimodal imaging. The nanoparticles were further functionalized with bombesin peptide for in vivo UCL/MR/CT imaging of prostate tumors.

[Effects of ApoE gene polymorphism on anti-inflammatory action of xuezhikang capsule].

OBJECTIVE: To study the effects of ApoE gene polymorphism on anti-inflammatory action of Xuezhikang Capsule. METHODS: One hundred and two patients with hyperlipidemia (as the treated group) and one hundred healthy volunteers (as the control group) were enrolled in the case-control study. Total DNA of the peripheral blood was extracted and ApoE genotypes were determined by PCR sequence analysis. The serum levels of tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and high sensitivity C reactive protein (hs-CRP)were measured in all subjects. The changes of TNF-alpha, IL-6, and hs-CRP were detected before and after 6-week Xuezhikang Capsule treatment, thus analyzing the correlation between ApoE gene polymorphism and changes of each inflammatory factor. RESULTS: The frequency of E3/3 genotype was 86% (86/100 cases)in the control group, significantly higher than that of the treated group (62.7%, 64/102 cases). The frequency of E3/4 genotype was 6% (6/100 cases) in the control group, significantly lower than that of the treated group (21.6%, 22/102 cases; both P < 0.05). Compared with the control group, the serum levels of TNF-alpha, IL-6, and hs-CPR were higher in the treated group before treatment (P < 0.05). In hyperlipidemia patients with E3/4 + E4/4 genotype, the serum level of TNF-alpha was higher than that of E3/3 genotype (P < 0.05); the serum level of IL-6 was higher than that of E2/E2 + E2/E3 genotype (P < 0.05); the serum level of hs-CRP was higher than that of E2/E2 + E2/E3 and E3/E3 genotype (P < 0.05). But there was no statistical difference in the serum levels of TNF-alpha, IL-6, or hs-CPR between E3/3 and E2/E2 + E2/E3 genotype. After 6-week intervention of Xuezhikang Capsule, the serum levels of TNF-alpha, IL-6, and hs-CRP were lower in the treated group (P < 0.05), but the serum levels of TNF-alpha and IL-6 were still higher than those of the control group (P < 0.05). But there was no statistical difference in the decrement of TNF-alpha, IL-6, or hsCRP among E2/E2 + E2/E3, E3/E3, or E3/4 + E4/4 genotypes (P > 0.05). CONCLUSIONS: The distribution of ApoE gene polymorphism is different between the hyperlipidemia patients and the healthy people. Chronic inflammatory reactions exist in hyperlipidemia patients, especially in those with e4 allele. Xuezhikang Capsule showed anti-inflammatory effects, but ApoE gene polymorphism did not affect its effects.