Separation and purification of alkaloids and phenolic acids from Phellodendron chinense by pH-zone refining and online-storage inner-recycling counter-current chromatography.

In this work, eight compounds from Phellodendron chinense were separated and purified by pH-zone refining counter-current chromatography and traditional counter-current chromatography coupled with online-storage inner-recycling counter-current chromatography (IRCCC). The pH-zone-refining mode was adopted for separating 2.0 g of crude extract with the solvent system of chloroform-methanol-water (4:3:3, v/v), in which 10 mM hydrochloric acid and 10 mM triethylamine were added in the stationary and mobile phases, respectively. Meanwhile, traditional counter-current chromatography coupled with online-storage IRCCC separation was performed by the solvent system of n-hexane-ethyl acetate-methanol-water (5:5:2:8, v/v). Finally, eight compounds, including six alkaloids as 6-methylpiperidin-2-one(1), isoplatydesmine(4), berlambine(5), epiberberine(6), palmatine(7), berberine(8) and two phenolic acids as ferulic acid(2), isoferulic acid(3), were successfully obtained using these three different CCC modes with the purities over 95.0%.

Preparative separation of eight phenolic acids from Echinacea purpurea L. Moench using pH-zone-refining counter-current chromatography and evaluation of their immunomodulatory effects and synergistic potential.

Phenolic acids headed by cichoric acid in Echinacea purpurea L. Moench show remarkable immunomodulatory effects. In this study, pH-zone-refining counter-current chromatography with a two-phase solvent system composed of EtOAc-ACN-H2O (4 : 1 : 5, v/v/v) (TFA (10 mM) in the upper phase and NH3·H2O (30 mM) in the lower phase) was applied to the pre-segmentation enrichment of 3.5 g of a crude sample of Echinacea purpurea L. Moench. Then two fractions of highly concentrated samples were further separated using EtOAc-H2O (1 : 1, v/v) and EtOAc-n-BuOH-ACN-H2O (3 : 1 : 1 : 5, v/v/v/v) solvent systems (TFA (10 mM) in the upper phase and NH3·H2O (10 mM) in the lower phase), separately. As a result, eight phenolic acids including cichoric acid were isolated successfully. Moreover, the immunomodulatory effects of the isolated compounds and the synergy of the binary and ternary compound combinations were first studied using CompuSyn software. And the ternary combination (caffeoyl tartaric acid + feruloyl tartaric acid + cichoric acid) showed a 94.91% synergistic inhibition rate of NO production released by LPS-induced RAW 264.7 cells. This study developed a strategy for the rapid preparative separation and purification of phenolic acids with complex components and large differences in content and provided a theoretical basis for the synergistic use of monomeric compounds in Echinacea purpurea L. Moench.

Preparation of a pyridyl covalent organic framework via Heck cross-coupling for solid-phase microextraction of perfluoropolyether carboxylic acids in food.

The growing detection of emerging perfluoropolyether carboxylic acids (PFECAs) in food has raised considerable concerns about their high persistence, bioaccumulation, and toxicity. In this study, a pyridine-functionalized covalent organic framework (Py-COF) was synthesized by introducing basic pyridyl groups into Br-COF via Heck cross-coupling. According to density functional theory, PFECAs were adsorbed in the pore sites of Py-COF via O-···HN+ interaction, which was the stable and predominant adsorption configuration. After systematic characterization, Py-COF was used as the coating for solid-phase microextraction combined with high-performance liquid chromatography-tandem mass spectrometry (SPME-HPLC-MS/MS) for the efficient determination of PFECAs in food. Under the optimum conditions, the method showed satisfactory linearity (R2 ≥ 0.998), low limits of detection (0.001-0.004 ng g-1), and good relative recoveries (82.5 %-112 %). The established method was satisfactorily used for the analysis of trace PFECAs in food samples.

Study protocol for a network meta-analysis of digital-technology-based psychotherapies for PTSD in adults.

INTRODUCTION: Studies on various types of digital-technology-based psychotherapies (DTPs) have indicated that they are effective for post-traumatic stress disorder (PTSD) symptom relief among adults. The intervention efficacy or effectiveness hierarchy, however, is still not clear. Therefore, we propose to conduct a network meta-analysis to assess the relative effectiveness of various types of DTPs. We aim to establish the differential effectiveness of these therapies in terms of symptom reduction and provide high-quality evidence for treating PTSD. METHODS AND ANALYSES: We will search Embase, CINAHL, MEDLINE, HealthSTAR, the Cochrane Library, PsycINFO, PubMed, the Chinese Biomedical Literature Database, clinical trials (eg, ClinicalTrials.gov) and other academic platforms for relevant studies, mainly in English and Chinese (as we plan to conduct a trial on PTSD patients in Wuhan, China, based on the results of this network meta-analysis), from inception to October 2020. Randomised controlled trials (RCTs) and meta-analyses investigating the effectiveness of any DTPs for PTSD patients for any controlled condition will be included. The number of intervention sessions and the research duration are unlimited; the effects for different durations will be tested via sensitivity analysis. For this project, the primary measure of outcome will be PTSD symptoms at the end of treatment using raw scores for one widely used PTSD scale, PCL-5. Secondary outcome measures will include (1) dropout rate; (2) effectiveness at longest follow-up, but not more than 12 months and (3) patients' functional recovery ratio (such as the return-to-work ratio or percentage of sick leave). Bayesian network meta-analysis will be conducted for all relative outcome measures. We will perform subgroup analysis and sensitivity analysis to see whether the results are influenced by study characteristics. The Grading of Recommendations, Assessments, Development, and Evaluation framework will be adopted to evaluate the quality of evidence contributing to network estimates of the primary outcome. ETHICS AND DISSEMINATION: The researchers of the primary trials already have had ethical approval for the data used in our study. We will present the results of this meta-analysis at academic conferences and publish them in peer-reviewed journals. PROSPERO REGISTRATION NUMBER: CRD42020173253.

One-dimensional CdS@Cd0.5Zn0.5S@ZnS-Ni(OH)2 nano-hybrids with epitaxial heterointerfaces and spatially separated photo-redox sites enabling highly-efficient visible-light-driven H2 evolution.

Photocatalytic solar-to-fuel conversion has been of great interest in recent years. Nevertheless, the rational structural manipulation of photocatalysts toward an efficient H2 evolution reaction (HER) is still under-developed. In this work, by employing CdS nanowires as the growth substrate, unique one-dimensional (1D) CdS@Cd0.5Zn0.5S@ZnS-Ni(OH)2 heterostructures were first synthesized through the ultrasonic water-bath reaction combined with subsequent hydrothermal and in situ photo-deposition processes. Under the optimized conditions, CS@30CZ0.5S@40ZS-3N with 30 wt% Cd0.5Zn0.5S, 40 wt% ZnS, and 3 wt% Ni(OH)2 achieves a visible-light-driven HER activity as high as 86.79 mmol h-1 g-1 (corresponding to an apparent quantum yield of 22.8% at 420 nm), which is 4 and 119 times higher than that of Pt-decorated CS@30CZ0.5S@40ZS and CdS, respectively. In addition, CdS@Cd0.5Zn0.5S@ZnS-Ni(OH)2 is also endowed with a good stability for H2 production under long-term irradiation. The spatial separation of photo-redox sites and epitaxial heterointerfaces in CdS@Cd0.5Zn0.5S@ZnS-Ni(OH)2 nanowires facilitate the charge transfer and separation effectively, accounting well for their superior photocatalytic capability. The results indicated in this work could benefit the exploitation of high-performance nanostructures for promising photocatalytic applications.

Molecularly imprinted polymers prepared from a single cross-linking functional monomer for solid-phase microextraction of estrogens from milk.

In this work, a single cross-linking functional monomer, 2,5-divinylterephthalaldehyde, was designed and synthesized to simplify the preparation of molecularly imprinted polymers (MIPs). In the presence of estradiol as a template, MIPs were successfully prepared using 2,5-divinylterephthalaldehyde along with a solvent and initiator. This method reduced most of the complex variables encountered in the traditional synthesis. Characterization of the morphology and structure of the MIPs was performed by scanning electron microscopy, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller analysis. Compared with non-imprinted polymers, the MIPs had higher adsorption capacities for five estrogens with imprinting factors above 2.9. The MIPs had high extraction efficiencies, good functional properties, long lifetimes, and good reproducibility, which made them suitable for solid-phase microextraction (SPME). Coupled with ultra-high performance liquid chromatography tandem mass spectrometry, the MIP-based fibers were applied to SPME for the analysis of five estrogens in milk samples. Under the best conditions, the established method had a wide linear range (0.5-10000 ng kg-1), low limits of detection (0.08-0.26 ng kg-1) and quantification (0.26-0.87 ng kg-1), good precision (3.2-8.1%, n = 6), and fiber-to-fiber reproducibility (4.3%-8.8%, n = 3). The MIPs-based fibers can be reused at least 60 times without apparent loss of extraction efficiency. Finally, this method was applied to the determination of target estrogens in milk samples with satisfactory relative recoveries (84.3%-105%, relative standard deviation ≤ 7.8%).

Bioactive cembrane diterpenoids from the gum resin of Boswellia carterii.

Eight new cembrane-type diterpenoids, boscartins AP-AW (1-8) were obtained from the gum resin of Boswellia carterii. Among which, six ones (2-7) were isomers, with one hydroxy group and two double bonds migrating along the carbocycle. The structures were elucidated by spectroscopic examination. All isolates were evaluated for anti-inflammatory activity and hepatoprotective activity by cell models of LPS-induced RAW 264.7 mouse peritoneal macrophages and APAP-induced HepG2 cells, respectively. As for anti-inflammatory activity assay, compound 1 exhibited potent activity against NO production (IC50 of 13.1 µM), with the other ones exhibiting weak anti-inflammatory activity (IC50 > 50 µM). As for hepatoprotective activity assay, compound 1 exhibited more significant activity (inhibition rate of 30.7%) than that of the positive control (bicyclol, inhibition rate of 27.2%), and compounds 4, and 6 showed nearly the same activities as the control (inhibition rates of 26.7% and 25.9%, respectively), with the other ones exhibiting weak hepatoprotective activity.

On-Tissue Derivatization Strategy for Mass Spectrometry Imaging of Carboxyl-Containing Metabolites in Biological Tissues.

Carboxyl-containing metabolites (CCMs) play indispensable roles in cell energy metabolism and cell-cell signaling. Profiling tissue CCMs with spatial signatures is significant for the understanding of molecular histology and may provide new clues to uncover the complex metabolic reprogramming of organisms in response to external or internal stimuli. Here, we develop a sensitive on-tissue CCMs derivatization method, coupled with matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), to visualize the spatial distributions of CCMs in biological tissues. A novel reagent, N,N,N-trimethyl-2-(piperazin-1-yl)ethan-1-aminium iodide (TMPA), was synthesized and used for the on-tissue derivatization of CCMs. Meanwhile, the on-tissue derivatization efficiency was significantly improved by introducing acetonitrile gas in the incubation system. With this methodology, a total of 28 CCMs, including 5 tricarboxylic acid cycle intermediates, 20 fatty acids, and 3 bile acids, were successfully detected and imaged in rat kidney tissues. More importantly, the introduction of a quaternary ammonium group into the chemical structure of CCMs enables simultaneous MALDI-MS imaging of tricarboxylic acid cycle intermediates, fatty acids, bile acids, and their metabolic pathway-related metabolites such as carnitines, cholines, glycerophosphocholine, phospholipids, and so on in the positive ion mode. This on-tissue derivatization MALDI-MSI approach was proven to be a powerful tool for probing the distributions and spatial metabolic networks of CMMs in biological tissues.

Noble metal-free 0D-1D NiCoP/Mn0.3Cd0.7S nanocomposites for highly efficient photocatalytic H2 evolution under visible-light irradiation.

Efficient and noble metal-free co-catalyst loading is an effective solution for separating and transferring photo-generated carriers and lowering the overpotential in photocatalytic H2 evolution activity. In this work, we designed and prepared a series of novel NiCoP/Mn0.3Cd0.7S (NCP/MCS) composites by modifying MCS nanorods with the co-catalyst NCP using a simple calcination method. Notably, the 10-NCP/MCS composite displays the optimum photocatalytic H2 evolution rate of 118.5 mmol g-1 h-1 under visible-light irradiation. This is approximately 3.39 times higher than that of pure MCS. The corresponding apparent quantum efficiency is 10.2% at 420 nm. The superior photocatalytic activity of the NCP/MCS composites can be attributed to the efficient separation of photogenerated carriers caused by the intimate heterojunction interface between NCP and MCS, smaller transfer resistance, and lower overpotential of NCP. Moreover, the NCP/MCS composites exhibit remarkable photostability. A plausible mechanism is proposed.

The choice of tissue fixative is a key determinant for mass spectrometry imaging based tumor metabolic reprogramming characterization.

The application of mass spectrometry imaging (MSI) for the study of spatiotemporal alterations of the metabolites in tumors has brought a number of significant biological results. At present, metabolite profiling based on MSI is typically performed on frozen tissue sections; however, the majority of clinical specimens need to be fixed in tissue fixative to avoid autolysis and to preserve antigenicity. In this study, we present the global impacts of different fixatives on the MS imaging of gastric cancer tissue metabolites. The MSI performances of 17 kinds of metabolites, such as amino acids, polyamines, cholines, organic acids, polypeptides, nucleotides, nucleosides, nitrogen bases, cholesterols, fatty acids, and phospholipids, in untreated, 10% formalin-, 4% paraformaldehyde-, acetone-, and 95% ethanol-fixed gastric cancer tissues were thoroughly explored for the first time. Furthermore, we also investigated the spatial expressions of 6 metabolic enzymes, namely, GLS, FASN, CHKA, PLD2, cPLA2, and EGFR, closely related to tumor-associated metabolites. Immunohistochemical staining carried out on the same tissue sections' which have undergone MSI analysis' suggests that enzymatic characterization is feasible after metabolite imaging. Combining the spatial signatures of metabolites and pathway-related metabolic enzymes in heterogeneous tumor tissues offers an insight to understand the complex tumor metabolism. Graphical abstract.

Cembrane-type diterpenoids from the gum resin of Boswellia carterii and their biological activities.

Eight new cembrane-type diterpenoids, boscartins AH-AK (1-8), along with two known ones (9-10), were isolated from the gum resin of Boswellia carterii. Compounds 1-3 were characteristic of high oxidation assignable to three epoxy groups, while compounds 4-8 were characteristic of two epoxy groups. Spectroscopic examination was used to elucidate their structures. All isolates were evaluated for antiproliferative activity against HCT-116 human colon cancer cells, anti-inflammatory activity against nitric oxide (NO) production, and hepatoprotective activity in vitro. All of them showed weak antiproliferative activity (IC50 > 100 µM), 8 exhibited potent inhibitory effects on NO production (IC50 of 14.8 µM), with the others showing weak anti-inflammatory activity (IC50 > 30 µM), and 1 exhibited more potent hepatoprotective activity than the positive control, bicyclol, at 10 µM against the damage induced by paracetamol in HepG2 cells.

Development of a high-coverage matrix-assisted laser desorption/ionization mass spectrometry imaging method for visualizing the spatial dynamics of functional metabolites in Salvia miltiorrhiza Bge.

Profiling the spatial distributions and dynamic changes of metabolites in plant tissue is critical to elucidate the complex metabolic regulation during plant growth, development, and responses to abiotic or biotic stresses. In this study, we developed a high-coverage MALDI-MS imaging method to visualize the spatial locations of a wide spectrum of metabolites in Salvia miltiorrhiza Bge. 1,5-Diaminonaphthalene (DAN) and 1,1'-binaphthyl-2,2'-diamine (BNDM) were optimized as MALDI matrices in positive and negative ion modes respectively, due to their low background interference and high sensitivity. Moreover, a simple organic washing protocol using acetone was shown to significantly improve the sensitivity of MALDI-MSI. Using this method, we successfully imaged the spatial locations of amino acids, phenolic acids, fatty acids, oligosaccharides, cholines, polyamines, tanshinones, and phospholipids in Salvia miltiorrhiza Bge. In addition, the distributions of some metabolites in Salvia miltiorrhiza Bge root and stem were found to exhibit good spatial match with plant tissue structure. Thus, our method provides a spatially-resolved way to map the plant metabolic networks and to understand the physiological roles of several plant metabolites.

[Effects of different temperature stress on cell membrane permeability,active oxygen metabolism and accumulation of effective substances in Lonicera japonicea].

The study is aimed to explore the effects of stress at different temperatures( 35,45,55 ℃) on membrane permeability,active oxygen metabolism and accumulation of effective substances in Lonicera japonica,and provide theoretical basis for reducing deterioration and revealing browning mechanism during postharvest processing of L. japonica. The cell membrane permeability( relative conductivity,MDA content),active oxygen metabolism( SOD,POD,PPO,CAT activity) and the accumulation of effective substances( chlorogenic acid,luteolin,neochlorogenic acid,cryptochlorogenic acid,3,5-dicaffeoylquinic acid,3,4-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid) of L. japonica were all studied by constant temperature drying method,and the results were analyzed by the SPSS 17. 0 statistical software. The results showed that MDA content in L. japonica was increased by 151. 14% at 35 ℃,SOD,POD,PPO and CAT activity were 29. 73%,42. 86%,105. 02% and 10. 74% higher than at 45 ℃,respectively. The order of effective substance content in L. japonica was 35 ℃ >45 ℃ >55 ℃. The changes of membrane permeability,activity of active oxygen metabolizing enzyme and accumulation of active components were significantly affected by different temperature stress. The indexes showed that physiological and active oxygen metabolizing enzyme activity of L. japonica was the highest under 35 ℃ stress,chlorogenic acid and luteolin were effectively accumulated,which provides basic data for solving browning problem in the postharvest processing of L. japonica.

Monodisperse cobalt(II) based metal-organic coordination polymer beads as a sorbent for solid-phase extraction of chlorophenoxy acid herbicides prior to their quantitation by HPLC.

Metal-organic coordination polymer beads (MOCBs) are described for use as a sorbent for solid-phase extraction of chlorophenoxy herbides. By applying regulation of Co(II) ions, micro-sized monodisperse MOCBs were obtained through the microwave heating. The MOCBs-based method displays excellent extraction efficiency towards chlorophenoxy herbicides, specifically of 2-chlorophenoxyacetic acid, 4-chlorophenoxyacetic acid, 4-chloromethylphenoxyacetic acid, 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid and 2-(2,4-dichlorophenoxy)propionic acid. Following extraction, the herbicides were eluted with 8% formic acid in methanol and quantified by HPLC. The method, when applied to analyze spiked cereals, exhibits a wide linear range (from 0.6 to 1000 ng g-1) and low limits of quantification (ranging from 0.10 to 0.25 ng g-1). For a single column, the inter-day and intra-day precisions, expressed as the relative standard deviation are in the range of 2.5-6.8%. The batch-to-batch reproducibility (for n = 3) is <4.6%. For spiked cereal samples, relative recoveries are very good (90.3-102.3%, for n = 4). The extraction efficiency of MOCBs remains unchanged after reusing for 40 times. Graphical abstractSchematic presentation of Co(II)-doped metal-organic coordination polymer beads (Co(II)@MOCB) using for solid-phase extraction (SPE).

Construction of direct Z-scheme system for enhanced visible light photocatalytic activity based on Zn0.1Cd0.9S/FeWO4 heterojunction.

A novel direct Z-scheme Zn0.1Cd0.9S/FeWO4 (ZCS/FW) photocatalyst was prepared by a facile calcination method. The photocatalytic performance was investigated by photodegradation rhodamine B (RhB) and photocatalytic production hydrogen (H2) under visible light irradiation. Compared with the pure ZCS, the ZCS/FW composites show considerably improved photocatalytic activity for degradation RhB and production H2. Noticeably, the ZCS/FW with 7 wt% of FW exhibits optimal photocatalytic activity with the H2 evolution rate of 34.6 mmol g-1 h-1 and photodegradation of about 98% of RhB solution (10 mg l-1) in 60 min. These outstanding photocatalytic performances were found to be ascribed to the formation of direct Z-scheme heterojunction, resulting in effective separation and transfer of photogenerated charge carriers. Moreover, active species trapping experiments further demonstrate the electrons transfer followed Z-scheme system, and the photocatalytic mechanism was proposed.

An improved 2D-HPLC-UF-ESI-TOF/MS approach for enrichment and comprehensive characterization of minor neuraminidase inhibitors from Flos Lonicerae Japonicae.

Flos Lonicerae Japonicae(Jinyinhua) possesses clearing heat and detoxification activity, and has been used as a traditional Chinese medicine to treat influenza for many years. Due to the complex chemical composition and diverse content of Jinyinhua, especially the many trace ingredients, the effective components are unknown. In this study, an improved two-dimensional high performance liquid chromatography-ultrafiltration combined with electrospray ionization-time-of-flight/mass spectroscopy (ESI-TOF/MS) approach was designed and used for the enrichment, screening and characterization of minor neuraminidase inhibitors in Jinyinhua. In the first dimension, semi-prep-HPLC was employed for the preliminary separation of different polarity components and enrichment of low content components from Jinyinhua extract. In the second dimension, hydrophilic interaction liquid chromatography and reverse phase-HPLC were used to separate the different polar fractions, respectively. The fractions then underwent ultrafiltration and ESI-TOF/MS for the comprehensive screening and characterization of potential neuraminidase inhibitors. As a result, a total of 44 compounds were found to have neuraminidase inhibitory activity, and 22 of these compounds were preliminarily identified by accurate molecular weight and UV absorption data compared with standards and references. The activity of 16 of these compounds was verified by the neuraminidase inhibition assay. This study provides support for the rapid screening of minor neuraminidase inhibitors from complex natural medicines.

Chemical constituents of Kopsia officinalis and their antagonizing high glucose-evoked podocyte injury activity.

Four new indole alkaloids (1-4) and twenty known compounds (5-24) were isolated from the leaves and stems, and fruits of Kopsia officinalis. Their structures were confirmed by means of spectroscopic methods. All these isolates were evaluated for their antagonizing high glucose-evoked podocyte injury activity for the first time, and compounds 5-8 showed potent activity with EC50 values of 3.0-12.0 µM.

Enhanced Photocatalytic Activity of ZnWO4/BiOI Composites Under Visible-Light Irradiation.

In this work, ZnWO4/BiOI composite photocatalysts were synthesized via a facile water bath method. The photocatalysts were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis diffusion reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy. Furthermore, the photocatalytic degradation of methylene blue (MB) using ZnWO4/BiOI was studied under the irradiation of visible-light. The results showed that ZnWO4/BiOI composites displayed much higher photocatalytic activity than pure ZnWO4 and BiOI. Among all the samples, ZnWO4/BiOI with the molar ratio of 5:5 (ZB-5) displayed the highest photocatalytic activity. The Enhancement of the photocatalytic activity primarily resulted from the effective separation of photogenerated electron-hole pairs. According to the radical scavengers experiments, ·O2- and h+ played an important role during the degradation process.

Rapid screening and purification of potential alkaloid neuraminidase inhibitors from Toddalia asiatica (Linn.) Lam. roots via ultrafiltration liquid chromatography combined with stepwise flow rate counter-current chromatography.

Toddalia asiatica (Linn.) Lam. is a medical plant traditionally used to treat coughs, fevers, and various diseases. Alkaloids are the main active ingredients in Toddalia asiatica (Linn.) Lam., but traditional methods for screening and separation are complex and labor-intensive. In this work, an efficient strategy was developed to rapidly screen, identify, and separate neuraminidase inhibitors from Toddalia asiatica (Linn.) Lam. Ultrafiltration, high performance liquid chromatography, and time-of-flight mass spectrometry were employed for rapid screening and identification of neuraminidase inhibitors. A two-phase solvent system comprising n-hexane/ethyl acetate/methanol/water (5:5:3:7, v/v) was then selected for separation by high-speed counter-current chromatography. A sample loading of 200 mg and a stepwise flow rate were achieved by increasing the flow rate from 2 to 4 mL/min after 4 h. Three main fluoroquinoline alkaloids (haplopine, skimmianine, and 5-methoxydictamnine) along with two coumarins were obtained via one-step separation and their structures were determined by mass spectrometry and nuclear magnetic resonance. In vitro assays revealed skimmianine with half-maximal inhibitory concentration of 16.2 ± 0.7 µmol/L was selected as the potential highest neuraminidase inhibitor. The results suggest that ultrafiltration high performance liquid chromatography-mass spectrometry combined with high-speed counter-current chromatography is efficient for the screening and isolation of neuraminidase inhibitors from complex natural products.

Unique 1D Cd1- x Znx S@O-MoS2 /NiOx Nanohybrids: Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Evolution via Integrated Structural Regulation.

Development of noble-metal-free photocatalysts for highly efficient sunlight-driven water splitting is of great interest. Nevertheless, for the photocatalytic H2 evolution reaction (HER), the integrated regulation study on morphology, electronic band structures, and surface active sites of catalyst is still minimal up to now. Herein, well-defined 1D Cd1- x Znx S@O-MoS2 /NiOx hybrid nanostructures with enhanced activity and stability for photocatalytic HER are prepared. Interestingly, the band alignments, exposure of active sites, and interfacial charge separation of Cd1- x Znx S@O-MoS2 /NiOx are optimized by tuning the Zn-doping content as well as the growth of defect-rich O-MoS2 layer and NiOx nanoparticles, which endow the hybrids with excellent HER performances. Specifically, the visible-light-driven (>420 nm) HER activity of Cd1- x Znx S@O-MoS2 /NiOx with 15% Zn-doping and 0.2 wt% O-MoS2 (CZ0.15 S-0.2M-NiOx ) in lactic acid solution (66.08 mmol h-1 g-1 ) is about 25 times that of Pt loaded CZ0.15 S, which is further increased to 223.17 mmol h-1 g-1 when using Na2 S/Na2 SO3 as the sacrificial agent. Meanwhile, in Na2 S/Na2 SO3 solution, the CZ0.15 S-0.2M-NiOx sample demonstrates an apparent quantum yield of 64.1% at 420 nm and a good stability for HER under long-time illumination. The results presented in this work can be valuable inspirations for the exploitation of advanced materials for energy-related applications.