Stable, high-performance sodium-based plasmonic devices in the near infrared.

Plasmonics enables the manipulation of light beyond the optical diffraction limit1-4 and may therefore confer advantages in applications such as photonic devices5-7, optical cloaking8,9, biochemical sensing10,11 and super-resolution imaging12,13. However, the essential field-confinement capability of plasmonic devices is always accompanied by a parasitic Ohmic loss, which severely reduces their performance. Therefore, plasmonic materials (those with collective oscillations of electrons) with a lower loss than noble metals have long been sought14-16. Here we present stable sodium-based plasmonic devices with state-of-the-art performance at near-infrared wavelengths. We fabricated high-quality sodium films with electron relaxation times as long as 0.42 picoseconds using a thermo-assisted spin-coating process. A direct-waveguide experiment shows that the propagation length of surface plasmon polaritons supported at the sodium-quartz interface can reach 200 micrometres at near-infrared wavelengths. We further demonstrate a room-temperature sodium-based plasmonic nanolaser with a lasing threshold of 140 kilowatts per square centimetre, lower than values previously reported for plasmonic nanolasers at near-infrared wavelengths. These sodium-based plasmonic devices show stable performance under ambient conditions over a period of several months after packaging with epoxy. These results indicate that the performance of plasmonic devices can be greatly improved beyond that of devices using noble metals, with implications for applications in plasmonics, nanophotonics and metamaterials.

Cytotoxic withanolides from the leaves of Datura stramonium L.

Six novel withanolides, along with nine known related compounds were isolated from the leaves of Datura stramonium L. The structures and absolute configurations of the new withanolides were elucidated by employing various spectral techniques and comparing them with those previously reported in the literature. In addition, four withanlides demonstrated interesting cytotoxic activity on LN229 cells with IC50 <20 µM.

Phenylpropanoids from Solanum capsicoides and their anti-inflammatory activity.

Two new phenylpropanoids, 4-O-(1''-O-cis-caffeoyl)-ß-glucopyran osyl-1-allyl-3-methoxy-benzene (1), 4'-O-(1''-O-cis-caffeoyl)-ß-glucopyranosyl-hydroxymegastigm-4-en-3-one (2), together with nine known compounds were obtained from the leaves of Solanum capsicoides. Their structures were elucidated based on spectroscopic methods, and comparing spectral data with those in literature. Meanwhile, their anti-inflammatory activities were evaluated on (LPS)-induced RAW 246.7 cells, and 1, 9, and 10 showed better inhibitory effects with IC50 values of 17.19 ± 1.12, 18.15 ± 0.47, and 19.8 ± 0.95 µM, respectively.

Cytotoxic Sesquiterpenoids from Atractylodes chinensis (DC.) Koidz.

Four new sesquiterpenoids named atrchiterpenes A-D (1-4), a new natural product (5), and twelve known compounds (6-17) were isolated from Atractylodes chinensis (DC.) Koidz. Compound 1 was a rare N-containing eudesmane-type sesquiterpenoid. Structure elucidation was performed by spectroscopic techniques, including 1D, 2D NMR spectra, and HR-ESI-MS. Compounds 6-11, 14, and 17 were reported from Atractylodes for the first time. All the isolated compounds were evaluated for cytotoxicity activity. Compound 16 showed moderate cytotoxicity against HepG2 cells with an IC50 value of 5.81±0.47.

Chemical Constituents of the Roots of Schisandra chinensis.

One new phenylpropanoid schineolignin D (1), one new sesquiterpene (-)-(7S,10S)-3,11,12,13-tetrahydroxycalamenene (2), one new quinic acid 4-(E)-O-coumaroylquinic acid ethyl ester (3), and seven known compounds 4-10 were separated from the roots of Schisandra chinensis. The chemical structures of all compounds were characterized by NMR spectroscopic experiments. All compounds were assessed for their neuroprotective effects on PC12 cell lines induced by H2 O2 . Compounds 1, 3-4, and 7 showed statistically significant neuroprotective activities with the negative control group at 12.5 µM.

Two new quinic acid derivatives from the leaves of Schisandra chinensis.

Two new (1-2) and three known quinic acid derivatives (3-5) were isolated from the leaves of Schisandra chinensis (Turcz) Baill. The structures of the compounds were determined by spectroscopic methods, especially the NMR techniques, and also by comparison with reported data in the literature. The cytotoxicity activities of these compounds were evaluated on human tumor cell lines LN229 and three of them showed a certain activity.

Inositol Derivatives with Anti-Inflammatory Activity from Leaves of Solanum capsicoides Allioni

Eight new inositol derivatives, solsurinositols A-H (1-8), were isolated from the 70% EtOH extract of the leaves of Solanum capsicoides Allioni. Careful isolation by silica gel column chromatography followed by preparative high-performance liquid chromatography (HPLC) allowed us to obtain analytically pure compounds 1-8. They shared the same relative stereochemistry on the ring but have different acyl groups attached to various hydroxyl groups. This was the first time that inositol derivatives have been isolated from this plant. The chemical structures of compounds 1-8 were characterized by extensive 1D nuclear magnetic resonance (NMR) and 2D NMR and mass analyses. Meanwhile, the in vitro anti-inflammatory activity of all compounds was determined using lipopolysaccharide (LPS)-induced BV2 microglia, and among the isolates, compounds 5 (IC50 = 11.21 ± 0.14 µM) and 7 (IC50 = 14.5 ± 1.22 µM) were shown to have potential anti-inflammatory activity.

[In vitro screening of natural compounds with antitumor activity by trypsin].

In order to investigate the feasibility of in vitro screening the antitumor activity of natural compounds by trypsin, porcine trypsin was used to for screening test, which is marked by inhibition of enzyme activity. Four compounds, namely daidzin, genistin, matrine and oxymatrine, were selected as test subjects. The natural antitumor drug camptothecin was used as the control. The inhibitory effect was detected by two experimental methods: direct detection of trypsin activity inhibition and hydrolysis of bovine serum albumin by trypsin. The results showed the inhibitory effects of the four natural compounds on trypsin, and the inhibition rates of the four natural compounds were significantly different. The enzyme activity assay showed that the inhibitory effect of matrine was better than that of oxymatrine, indicating that trypsin had a good screening resolution. The inhibitory effect was significantly increased with the increased ratio of sample to trypsin, suggesting the structure-activity correlation and dose-effect correlation of the screening methods. Altogether, the experimental method of screening antitumor activity of natural compounds by trypsin has good application values. Since porcine trypsin is similar to human trypsin in terms of molecular structure and performance, it is more applicable for screening of antitumor efficacy of natural pharmacodynamic compounds.

Ecdysteroids from the Aerial Parts of Paris verticillata.

Two new ecdysteroids 14-epi-polypodine B (1) and 22-oxo-hydroxyecdysterone (2), along with nine known compounds, polypodine B (3), viticosterone E (4), 20-hdroxyecdysone-2-acetate (5), 22-oxo-20-hydroxyecdysone (6), 5-hydroxyecdysone (7), pinnatasterone (8), 3-epi-20-hydroxyecdysone (9), ecdysterone (10) and stachysterone B (11), were isolated from the aerial parts of Paris verticillata. The structures of all compounds were elucidated by extensive spectroscopic analysis, quantum chemical calculations and ANN-PRA/DP4+ probability analysis. Among them, the absolute configuration of compound 1 and 2 was unambiguous determined by ECD. Also, the isolated compounds were assessed for their cytotoxic activities. Compounds 2, 3 and 7 exhibited significant cytotoxic activities against PC12, LN299 and SMCC7721 cells.

Discovery of Active Ingredients Targeted TREM2 by SPR Biosensor-UPLC/MS Recognition System, and Investigating the Mechanism of Anti-Neuroinflammatory Activity on the Lignin-Amides from Datura metel Seeds.

As a new target protein for Alzheimer's disease (AD), the triggering receptor expressed on myeloid Cells 2 (TREM2) was expressed on the surface of microglia, which was shown to regulate neuroinflammation, be associated with a variety of neuropathologic, and regarded as a potential indicator for monitoring AD. In this study, a novel recognition system based on surface plasmon resonance (SPR) for the TREM2 target spot was established coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-MS), in order to screen the active ingredients targeting TREM2 from Datura metel seeds. The results showed that four lignan-amides were discovered as candidate compounds by SPR biosensor-UPLC/MS recognition analysis. According to the guidance of the active ingredients discovered by the system, the lignin-amides from Datura metel seeds (LDS) were preliminarily identified as containing 27 lignan-amides, which were enriched compositions by the HP-20 of Datura metel seeds. Meanwhile, the anti-inflammatory activity of LDS was evaluated in BV2 microglia induced by LPS. Our experimental results demonstrated that LDS could reduce NO release in LPS-treated BV2 microglia cells and significantly reduce the expression of the proteins of inducible Nitric Oxide Synthase (iNOS), cyclooxygenase 2 (COX-2), microtubule-associated protein tau (Tau), and ionized calcium-binding adapter molecule 1 (IBA-1). Accordingly, LDS might increase the expression of TREM2/DNAX-activating protein of 12 kDa (DAP12) and suppress the Toll-like receptor SX4 (TLR4) pathway and Recombinant NLR Family, Pyrin Domain Containing Protein 3 (NLRP3)/cysteinyl aspartate specific proteinase-1 (Caspase-1) inflammasome expression by LDS in LPS-induced BV2 microglial cells. Then, the inhibitory release of inflammatory factors Interleukin 1 beta (IL-1ß), Interleukin 6 (IL-6), and Tumor necrosis factor-alpha (TNFα) inflammatory cytokines were detected to inhibit neuroinflammatory responses. The present results propose that LDS has potential as an anti-neuroinflammatory agent against microglia-mediated neuroinflammatory disorders.

In search of microbial indicator taxa: shifts in stream bacterial communities along an urbanization gradient.

A majority of environmental studies describe microbiomes at coarse scales of taxonomic resolution (bacterial community, phylum), ignoring key ecological knowledge gained from finer-scales and microbial indicator taxa. Here, we characterized the distribution of 940 bacterial taxa from 41 streams along an urbanization gradient (0%-83% developed watershed area) in the Raleigh-Durham area of North Carolina (USA). Using statistical approaches derived from macro-organismal ecology, we found that more bacterial taxa were classified as intolerant than as tolerant to increasing watershed urbanization (143 vs 48 OTUs), and we identified a threshold of 12.1% developed watershed area beyond which the majority of intolerant taxa were lost from streams. Two bacterial families strongly decreased with urbanization: Acidobacteriaceae (Acidobacteria) and Xanthobacteraceae (Alphaproteobacteria). Tolerant taxa were broadly distributed throughout the bacterial phylogeny, with members of the Comamonadaceae family (Betaproteobacteria) presenting the highest number of tolerant taxa. Shifts in microbial community structure were strongly correlated with a stream biotic index, based on macroinvertebrate composition, suggesting that microbial assemblages could be used to establish biotic criteria for monitoring aquatic ecosystems. In addition, our study shows that classic methods in community ecology can be applied to microbiome datasets to identify reliable microbial indicator taxa and determine the environmental constraints on individual taxa distributions along environmental gradients.

Butyrate suppresses abnormal proliferation in colonic epithelial cells under diabetic state by targeting HMGB1.

Butyrate is widely accepted as a proliferation inhibitor in colon cancer but less thoroughly characterized in the colonic epithelium of objects with type 2 diabetes mellitus. The present study investigated the regulatory effect of butyrate on proliferation, the related molecule high-mobility group box 1 (HMGB1) and the receptor for advanced glycation end products (RAGE) in the colon of db/db type 2 diabetic model mice and non-cancerous NCM460 colon cells. Proliferation and the expression of HMGB1 and RAGE were increased and could be partially reversed by butyrate treatment in the colon of db/db mice, which were consistent in NCM460 cells under a high glucose state. In NCM460 cells, under the normal glucose state, proliferation increased by overexpression of HMGB1. Under a high glucose state, increased expression of HMGB1 was accompanied with a release from cell nuclei into the cytoplasm and extracellular matrix. Down-regulation of HMGB1 could lower the expression of RAGE and attenuate the abnormally increased proliferation. And overexpression of HMGB1 reversed the suppressing effect of butyrate on abnormally increased proliferation. Conclusively, butyrate suppressed the abnormally increased proliferation in colonic epithelial cells under diabetic state by targeting HMGB1.

Butyrate ameliorated-NLRC3 protects the intestinal barrier in a GPR43-dependent manner.

BACKGROUND: Intestinal barrier dysfunctions are related to dysbacteriosis and chronic gut inflammation in type 2 diabetes. Although there is emerging evidence that the chronic gut inflammatory response is stimulated by nucleotide-binding oligomerization domain-like receptors (NLRs), the relationship and precise mechanism between NLRC3 and the colonic epithelial barrier remains largely elusive. METHODS: We investigated the function and mechanism of NLRC3 in the colonic tissues of diabetic mice and colonic epithelial cell lines. The regulatory mechanism between NLRC3, butyrate and tight junctions was elucidated via a transepithelial electrical resistance measurement, transmission electron microscopy, RNA interference and western blotting. RESULTS: In this study, we found that NLRC3 expression was decreased in the colonic tissues of diabetic mice. NLRC3 over-expression ameliorated colonic epithelial barrier integrity and up-regulated tight junction proteins in colonic epithelial cells. Knockdown of TRAF6 diminished NLRC3-induced ZO-1/occludin expression. In addition, we demonstrated that butyrate could stimulate NLRC3 expression in both diabetic mice and colonic epithelial cells. GPR43 on colonic epithelial cells is involved in the activation of NLRC3 induced by butyrate. CONCLUSION: Our findings demonstrated that NLCR3 could ameliorate colonic epithelial barrier integrity in diabetes mellitus in a TRAF6-dependent manner, and NLCR3 was stimulated by butyrate via binding GPR43 on colonic epithelial cells.

Structural insight into the serotonin (5-HT) receptor family by molecular docking, molecular dynamics simulation and systems pharmacology analysis.

Serotonin (5-HT) receptors are proteins involved in various neurological and biological processes, such as aggression, anxiety, appetite, cognition, learning, memory, mood, sleep, and thermoregulation. They are commonly associated with drug abuse and addiction due to their importance as targets for various pharmaceutical and recreational drugs. However, due to a high sequence similarity/identity among 5-HT receptors and the unavailability of the 3D structure of the different 5-HT receptor, no report was available so far regarding the systematical comparison of the key and selective residues involved in the binding pocket, making it difficult to design subtype-selective serotonergic drugs. In this work, we first built and validated three-dimensional models for all 5-HT receptors based on the existing crystal structures of 5-HT1B, 5-HT2B, and 5-HT2C. Then, we performed molecular docking studies between 5-HT receptors agonists/inhibitors and our 3D models. The results from docking were consistent with the known binding affinities of each model. Sequentially, we compared the binding pose and selective residues among 5-HT receptors. Our results showed that the affinity variation could be potentially attributed to the selective residues located in the binding pockets. Moreover, we performed MD simulations for 12 5-HT receptors complexed with ligands; the results were consistent with our docking results and the reported data. Finally, we carried out off-target prediction and blood-brain barrier (BBB) prediction for Captagon using our established hallucinogen-related chemogenomics knowledgebase and in-house computational tools, with the hope to provide more information regarding the use of Captagon. We showed that 5-HT2C, 5-HT5A, and 5-HT7 were the most promising targets for Captagon before metabolism. Overall, our findings can provide insights into future drug discovery and design of medications with high specificity to the individual 5-HT receptor to decrease the risk of addiction and prevent drug abuse.

Epigenetic modification of TLE1 induce abnormal differentiation in diabetic mice intestinal epithelium.

The intestinal epithelium cells (IECs) in diabetes mellitus (DM) patients have been proven to be abnormally differentiated. During the differentiation of IECs, epigenetic modification acts as an important regulator. In this study, we aimed to examine the epigenetic alteration of Transducin-like Enhancer of Split 1 (TLE1), a multitask transcriptional co-repressor, contributing to the differentiation homeostasis in IECs of DM mice. The IECs of type 2 diabetic mice model were isolated and collected. Methylation states of whole genomic DNA promoter regions were investigated by microarray. Methylated-specific PCR was used to detect the methylation state of TLE1 promoter in DM mice IECs. The expression of TLE1, Hes1, and differentiated cell markers were measured through real-time PCR, Western blots, and immunohistochemistry; by transfection assay, TLE1 or Hes1 was independently down-regulated in intestinal epithelium cell line, IEC-6. Subsequent modulation on TLE1, Hes1, and differentiated intestinal cell markers were detected. Global gene promoter regions in DM intestinal epithelium were less methylated comparing to normal control. The expression of TLE1 was significantly increased via hypomethylated activation in DM mice IECs. Hes1 was significantly suppressed and the terminal cell markers abnormally expressed in DM mice IECs (P < 0.05). Inhibition or induction on the abundance of TLE1 in IEC-6 cell line resulted in the corresponding dysregulation of Hes1 and intestinal epithelium differentiation (P < 0.05). Demethylation of TLE1 promoter region activates the self-expression in diabetic mice IECs. Subsequently, TLE1, through the transcriptional suppression on expression of Hes1, contributes to the aberrant differentiation of IECs in DM mice.

Catalytic Hairpin Assembly-Based Self-Ratiometric Gel Electrophoresis Detection Platform for Reliable Nucleic Acid Analysis.

The development of gel electrophoresis-based biodetection assays for point-of-care analysis are highly demanding. In this work, we proposed a ratiometric gel electrophoresis-based biosensing platform by employing catalytic hairpin assembly (CHA) process functions as both the signal output and the signal amplification module. Two types of nucleic acids, DNA and miRNA, are chosen for demonstration. The proposed strategy indeed provides a new paradigm for the design of a portable detection platform and may hold great potential for sensitive diagnoses.

Polyacetylenes from Saposhnikovia divaricata and their anticancer activity.

Nine polyacetylenes, including five new compounds named sadivaethynes E-I (1-5), were isolated from the roots of Saposhnikovia divaricata. Structural elucidation of compounds 1-5 was established by extensive spectroscopic analysis, quantum chemical calculations and DP4+ probability analysis. Among them, the absolute configuration of compound 1-2, 4-5 was unambiguous determined by ECD. Also, all compounds were evaluated for cytotoxicity against two human cancer cell lines (A549, HEPG2) in vitro, compound 9 showed moderate inhibitory effect with an IC50 value of 11.66 µM against HEPG2.

Chemical constituents from the Saposhnikovia divaricata and their antiproliferative activity.

Nine compounds were isolated and identified from ethanolic extracts of Saposhnikovia divaricata, including one new alkaloid (1), one new pentacyclic triterpenoid (9), and seven known alkaloids (2-8). Structural elucidation of compounds 1 and 9 was established by 1D and 2D NMR spectra referring to the literature, together with high-resolution mass spectrometric analysis. All compounds were evaluated for antiproliferative activity against two cancer cell lines (LN229, A549) in vitro. Compounds (1-9) showed no significant antiproliferative activity.

Influence on the fermentation quality, microbial diversity, and metabolomics in the ensiling of sunflower stalks and alfalfa.

With the rapid development of the livestock industry, finding new sources of feed has become a critical issue that needs to be addressed urgently. China is one of the top five sunflower producers in the world and generates a massive amount of sunflower stalks annually, yet this resource has not been effectively utilized. Therefore, in order to tap into the potential of sunflower stalks for animal feed, it is essential to explore and develop efficient methods for their utilization.In this study, various proportions of alfalfa and sunflower straw were co-ensiled with the following mixing ratios: 0:10, 2:8, 4:6, 5:5, 6:4, and 8:2, denoted as A0S10, A2S8, A4S6, A5S5, A6S4, and A8S2, respectively. The nutrient composition, fermentation quality, microbial quantity, microbial diversity, and broad-spectrum metabolomics on the 60th day were assessed. The results showed that the treatment groups with more sunflower straw added (A2S8, A4S6) could start fermentation earlier. On the first day of fermentation, Weissella spp.dominated overwhelmingly in these two groups. At the same time, in the early stage of fermentation, the pH in these two groups dropped rapidly, which could effectively reduce the loss of nutrients in the early stage of fermentation.In the later fermentation period, a declining trend in acetic acid levels was observed in A0S10, A2S8, and A4S6, while no butyric acid production was detected in A0S10 and A2S8 throughout the process. In A4S6, butyric acid production was observed only after 30 days of fermentation. From the perspective of metabolites, compared with sunflower ensiling alone, many bioactive substances such as flavonoids, alkaloids, and terpenes are upregulated in mixed ensiling.

A new 3,4-dihydroisocoumarin and an antiinflammatory coumarin from the roots of Saposhnikovia divaricata (Turcz.) Schischk.

Phytochemical investigation of the roots of Saposhnikovia divaricata (Turcz.) Schischk resulted in the isolation of twelve coumarin derivatives including one new 3,4-dihydroisocoumarin (1) and eleven known 3,4-unsubstituted coumarins (2-12). Structural elucidation of compounds 1-12 was established by 1D and 2D NMR spectra referring to the literature, together with high-resolution mass spectrometric analysis. LPS-induced RAW264.7 inflammatory cell model was used to determine the potential antiinflammation activity of all the isolated compounds in vitro. The results showed that compound 3 significantly inhibited the production of lipopolysaccharide (LPS)-induced NO in macrophages (IC50 = 4.54 ± 1.71 µM), more active than the positive control (L-NMMA).