Preparation of alkyl microporous organic network-based capillary column for an efficient gas chromatographic separation of position isomers.

The large surface area, excellent thermal stability and easy modification make microporous organic networks (MONs) good candidates in the field of gas chromatography (GC). Due to the limited species and highly conjugated networks of MONs, their applications are still in infancy and restricted. To accelerate their developments and to enrich their types in GC, here we report the first example of synthesizing alkyl MON and its capillary column for GC separation of position isomers. Linear 1,8-dibromooctane is used as the alkyl monomer instead of traditional aromatic ones to construct novel alkyl MON to decrease the inherent conjugated characteristic of MONs. The alkyl MON exhibits good thermal stability (up to 350°C), large surface area (1173 m2 g-1), and non-polar character, allowing good resolution for alkanes, alkyl benzenes, alcohols, ketones, and diverse position isomers, including dichlorobenzene, trichlorobenzene, bromotoluene, nitrotoluene, methylbenzaldehyde, and ionone with the limits of detection (0.003 mg mL-1) and limits of quantitation of (0.10 mg mL-1). The in situ growth-prepared alkyl MON column demonstrates remarkable duration time and precisions for the retention relative standard deviations, (RSDs%, intra-day, n = 7), 0.06%-0.53% (intra-day, n = 7), and 2.87%-10.59% (column-to-column, n = 3). In addition, the fabricated alkyl MON-coated capillary column offers better resolution than three commercial GC columns for the resolution of methylbenzaldehyde, bromotoluene, and chlorotoluene isomers. This work reveals the practicability for synthesizing alkyl MONs and demonstrates their prospects for position isomers separation.

Click postsynthesis of microporous organic network@silica composites for reversed-phase/hydrophilic interaction mixed-mode chromatography.

Recently, the good physical and chemical properties, well-defined pore architectures, and designable topologies have made microporous organic networks (MONs) excellent potential candidates in high-performance liquid chromatography (HPLC). However, their superior hydrophobic structures restrict their application in the reversed-phase mode. To solve this obstacle and to expand the application of MONs in HPLC, we realized the thiol-yne "click" postsynthesis of a novel hydrophilic MON-2COOH@SiO2-MER (MER denotes mercaptosuccinic acid) microsphere for reversed-phase/hydrophilic interaction mixed-mode chromatography. SiO2 was initially decorated with MON-2COOH using 2,5-dibromoterephthalic acid and tetrakis(4-ethynylphenyl)methane as monomers, and MER was then grafted via thiol-yne click reaction to yield MON-2COOH@SiO2-MER microspheres (5 µm) with a pore size of ~1.3 nm. The -COOH groups in 2,5-dibromoterephthalic acid and the post-modified MER molecules considerably improved the hydrophilicity of pristine MON and enhanced the hydrophilic interactions between the stationary phase and analytes. The retention mechanisms of the MON-2COOH@SiO2-MER packed column were fully discussed with diverse hydrophobic and hydrophilic probes. Benefiting from the numerous -COOH recognition sites and benzene rings within MON-2COOH@SiO2-MER, the packed column exhibited good resolution for the separation of sulfonamides, deoxynucleosides, alkaloids, and endocrine-disrupting chemicals. A column efficiency of 27,556 plates per meter was obtained for the separation of gastrodin. The separation performance of the MON-2COOH@SiO2-MER packed column was also demonstrated by comparing with those of MON-2COOH@SiO2, commercial C18, ZIC-HILIC, and bare SiO2 columns. This work highlights the good potential of the thiol-yne click postsynthesis strategy to construct MON-based stationary phases for mixed-mode chromatography.

Cross-cultural adaptation and psychometric validation of the Chinese version of career success in nursing scale (CSNS).

OBJECTIVE: To translate the career success in nursing scale (CSNS) into Chinese and evaluate its psychometric properties. BACKGROUND: A lower sense of career success seriously affects the enthusiasm of nurses and increases their turnover rate. Therefore, an accurate assessment of the career success level of nurses is necessary. However, China does not have a professional tool for assessing the career success of nurses. METHODS: The stratified sampling method was used to recruit participants from 22 hospitals of different grades in 5 cities in China. A total of 650 and 348 subjects were selected for item analysis and reliability and validity tests, respectively, of the translated initial scale. RESULTS: The Chinese version of the CSNS (C-CSNS) with 33 items had good psychometric properties. Cronbach's α was 0.960, split-half reliability was 0.893, and ICC within two weeks was 0.981. Exploratory factor analysis extracted 5 common factors that explained 63.73% of the total variance, and confirmatory factor analysis supported acceptable construct validity. CONCLUSION: The C-CSNS has adequate construct validity and excellent psychometric properties and can be used for accurate assessment of nurses' career success. IMPLICATIONS FOR NURSING MANAGEMENT: A new tool that is more suitable for the Chinese hospital nursing context is available for evaluating Chinese clinical nurses' career success. Nursing managers can formulate appropriate management strategies according to the evaluation results to assist nurses in career development planning, thereby improving their career success level.

Fabrication of microporous organic network@silica composite for high-performance liquid chromatographic separation of drugs and proteins.

Microporous organic networks (MONs) that exhibit good stability and hydrophobicity are promising candidates for performing HPLC separation of small organic compounds. However, their applications in separating large analytes as well as biomolecules are still limited by the microporous nature of MONs. Herein, we demonstrated the fabrication of a MON-functionalized silica (MON@SiO2 ), exhibiting micro and mesopores for the HPLC separations of small drugs as well as large analytes, such as flavones, nonsteroidal anti-inflammatory drugs (NSAIDs), endocrine disrupting chemicals (EDCs), and proteins. MON was successfully modified on SiO2 microspheres to yield the uniform and mono-dispersed MON@SiO2 . The separation mechanisms and performance of the MON@SiO2 packed column were evaluated for a wide range of analytes, including neutral, acidic, basic compounds, drugs, and proteins. Compared with commercial C18 and SiO2 -NH2 packed columns, the proposed MON@SiO2 column afforded superior performance in the separations of flavones, NSAIDs, EDCs, and proteins. Moreover, the MON@SiO2 column also offered good repeatability with intraday RSDs (n = 7) of <0.1%, <2.0%, <2.3%, and <0.7% for the retention time, peak height, peak area, and half peak width, respectively, for separating EDCs. This work proved the potential of using MONs in the HPLC separations of drugs and proteins.

In situ fabrication of microporous organic network coated capillary column for high resolution gas chromatographic separation of hydrocarbons.

Microporous organic networks (MONs) are a new class of porous materials synthesized via Sonogashira coupling reactions between organic building blocks. Here we report an in situ synthesis approach to fabricate MONs coated capillary column for high resolution GC separation of hydrocarbons. The McReynolds constant evaluation reveals the MONs coated capillary is a non-polar column. The MONs coated capillary column shows good resolution for GC separation of diverse important industrial hydrocarbons such as linear and branched alkanes, alkylbenzenes, pinene isomers, ethylbenzene and styrene, cyclohexane and benzene. The MONs coated capillary column gave a high column efficiency of 1542 plates per meter for hexane and good precision for replicate separations of the selected hydrocarbons with the RSDs of 0.2-0.3, 1.5-3.1, and 1.9-3.3% for retention time, peak height and peak area, respectively. The MONs coated capillary also offered better resolution than commercial Inert Cap-1 and Inert Cap-5 capillary columns for hexane and heptane isomers. These results reveal the potential of MONs as novel stationary phases in GC.

[Metabonomics study on hepatoprotective effect of Schisandrae Chinensis Fructus based on UPLC-Q-TOF-MS].

To investigate the hepatoprotective effect of Schisandrae Chinensis Fructus (SCF) on CCl4-induced liver injury, observe its effect on serum metabolites, explore its scientific connotation in liver preservation and find the biomarkers for hepatoprotective effect of SCF. Liver injury model was established by using CCl4. The pathological sections of liver tissues were observed and the contents of alanine transaminase (ALT) and aspartate transaminase (AST) in serum were determined. The metabolic skills were adopted based on ultra performance liquid chromatography time-of-flight mass spectrometry (UPLC-Q-TOF-MS), principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) for screening and identification of biomarkers related to liver injury. The results showed the metabolites in blank group, model group and administration group could be easily distinguished, 50 differential compounds were identified and 7 possible metabolic pathways of liver protection were enriched. In this experiment, the hepatoprotective effect of SCF was verified, and the related metabolic pathways such as amino acid metabolism, vitamin metabolism and glycerophospholipid metabolism were discussed.

[Advances in studies on pharmacological action of main chemical constituent of Curcuma Zedoary in preventing in-stent restenosis].

Traditional Chinese medicine Curcuma Zedoary ( E'Zhu) contains essential oil, curcuminoid and other effective constituents, with such pharmacological actions as anti-platelet aggregation, lowing blood lipid, anti-oxidation and anti-inflammation. In recent years, studies have showed that certain extracts and chemical components of E'Zhu could mitigate myocardial cell mitochondria injury and protect vascular endothelium by enhancing heme oxygenase-1 activity, inhibit nuclear factor NF-kappaB, target genes interleukin-associated kinase-1 (IRAK-1), tumor necrosis factor receptor-6 (TRAF-6) and vascular cell adhesion molecule-1 (VCAM-1), reduce inflammatory infiltration, and inhibit growth factor-induced smooth muscle cells (SMCs) proliferation and migration by impacting oxidation of cellular phosphatases. Due to its different functions in vascular endothelial cells and smooth muscle cells, E'Zhu has been applied in drug-eluting stents, with a potential effect in preventing in-stent restenosis and thrombogenesis. In this paper, studies on pharmacological effects and mechanisms of extracts and main chemical constituents from E'Zhu in preventing vascular restenosis were summarized.

[Effect of Psoraleae Fructus and Myristicae Semen in "Ershen pill" on serum metabonomics in spleen-kidney Yang deficiency diarrhea rats before and after processing].

The metabonomics method was used to study the intervention effect of Psoraleae Fructus and Myristicae Semen in "Ershen pill" on the changes in serum endogenous metabolites in spleen-kidney Yang deficiency diarrhea rats before and after processing, screen out differentiated metabolites related to spleen-kidney Yang deficiency diarrhea and explore the metabolic patterns related to spleen-kidney Yang deficiency diarrhea and the processing synergy mechanism of Psoraleae Fructus and Myristicae Semen in "Ershen pill". Efforts were made to detect SOD and MDA of each group, test rat serum metabolic fingerprints in different stages by using GC-MS, analyze by PCA and PLS-DA methods and screen out potential biomarks through VIP and t test. The results revealed that "Ershen pill" could enhance the level of SOD and decrease the level of MDA and identified 10 differentiated metabolites related to spleen-kidney Yang deficiency diarrhea. Compared with the model group, all of metabolites recovered to varying levels after being intervened with "Ershen pill", with the best effect shown in the "Ershen pill" IV group (salt-processed Psoraleae Fructus + bran-roasted Myristicae Semen). It is speculated that that Psoraleae Fructus and Semen Myristicae in "Ershen pill" show a synergistic effect by inhibiting peroxide, improving aglucolipid, amino acids and energy metabolism, with multiple target sites.

Explaining calcium-dependent gating of anoctamin-1 chloride channels requires a revised topology.

RATIONALE: Ca2+ -activated Cl channels play pivotal roles in the cardiovascular system. They regulate vascular smooth muscle tone and participate in cardiac action potential repolarization in some species. Ca2+ -activated Cl channels were recently discovered to be encoded by members of the anoctamin (Ano, also called Tmem16) superfamily, but the mechanisms of Ano1 gating by Ca2+ remain enigmatic. OBJECTIVE: The objective was to identify regions of Ano1 involved in channel gating by Ca2+. METHODS AND RESULTS: The Ca2+ sensitivity of Ano1 was estimated from rates of current activation, and deactivation in excised patches rapidly switched between zero and high Ca2+ on the cytoplasmic side. Mutation of glutamates E702 and E705 dramatically altered Ca2+ sensitivity. E702 and E705 are predicted to be in an extracellular loop, but antigenic epitopes introduced into this loop are not accessible to extracellular antibodies, suggesting this loop is intracellular. Cytoplasmically applied membrane-impermeant sulfhydryl reagents alter the Ca2+ sensitivity of Ano1 E702C and E705C as expected if E702 and E705 are intracellular. Substituted cysteine accessibility mutagenesis of the putative re-entrant loop suggests that E702 and E705 are located adjacent to the Cl conduction pathway. CONCLUSIONS: We propose an alternative model of Ano1 topology based on mutagenesis, epitope accessibility, and cysteine-scanning accessibility. These data contradict the popular re-entrant loop model by showing that the putative fourth extracellular loop (ECL 4) is intracellular and may contain a Ca2+ binding site. These studies provide new perspectives on regulation of Ano1 by Ca2+.

Phenolic glycosides from Glycosmis pentaphylla.

Three new phenolic glycosides, named as glycopentosides A-C (1-3), along with nine known compounds were isolated from the n-BuOH extract of stems of Glycosmis pentaphylla. Their structures were determined by using spectroscopic and chemical methods. Bioassay showed that compound 10 (tachioside) could inhibit nitric oxide production in lipopolysaccharides-stimulated RAW 264.7 cells with IC50 value of 12.14 µM.

Fabrication of magnetic Fe3O4 doped ß-cyclodextrin microporous organic network for the efficient extraction of endocrine disrupting chemicals from food takeaway boxes.

Endocrine disrupting chemicals (EDCs) are a typical class of natural or man-made endogenous hormone agonists or antagonists that can directly or potentially interfere with human endocrine system. However, it is still difficult to analyze trace EDCs directly from complex environment and food matrices. Therefore, the proper sample pretreatment is highly desired and the preparation of efficient adsorbents is of great challenge and importance. Herein, we report the facile one-pot solvothermal synthesis of Fe3O4 nanoparticle doped magnetic ß-cyclodextrin microporous organic network composites (MCD-MONs) for the magnetic solid phase extraction (MSPE) of four phenolic EDCs in water and food takeaway boxes prior to the high-performance liquid chromatography analysis. The sheet-like Fe3O4 doped MCD-MONs offered good magnetic property (16.5 emu g-1) and stability, and provided numerous hydrogen bonding, hydrophobic, π-π, and host-guest interaction sites for EDCs. Under the optimal experimental conditions, the established method was successfully verified with wide linear range (2.0-1000 µg L-1), low limits of detection (0.6-1.0 µg L-1), good precisions (intra-day and inter-day RSDs < 5.2 %, n = 3), large enrichment factors (88-98) and adsorption capacity (90.3-255.8 mg g-1), short extraction time (6 min), less adsorbent consumption (3 mg), and good reusability (at least 8 times) for EDCs. The proposed method was successfully applied to detect the trace EDCs in real samples with the recovery of 84.0-99.7 %. This work demonstrated the great potential of MCD-MONs for the efficient MSPE of trace EDCs from complex food takeaway boxes and water samples and uncovered the prospect of CD-based MONs in sample pretreatment.

Novel phenazine-based microporous organic network for selective and sensitive determination of trace sulfonamides in milk samples.

BACKGROUND: Sulfonamide (SA) residues in food of animal origin possess a potential threat to human health and environment. However, due to the polar and ionic characteristics and trace level of SAs and the complexity of food matrices, direct measurement of SAs in these samples is still very difficult. Development of efficient sample pretreatment method for sensitive and selective extraction of trace SAs is of great significance and urgently desired. Therefore, rational design and synthesizing advanced and selective extractants is quite important. RESULTS: In this work, a novel phenazine-based microporous organic network (MON) named TEPM-DP is reasonably synthesized and employed as a packing material for selective solid phase extraction (SPE) and sensitive determination of four typical SAs in milk samples. Phenazine-based monomer with aromatic and heteroaromatic ring and numerous N atoms is chosen to construct TEPM-DP adsorbent to provide π-π, hydrogen bonding, hydrophobic, and electrostatic extraction sites for SAs. The proposed method owns wide linear ranges, low limits of detection, high enrichment factors, and good precisions and recoveries for SAs in complex milk samples. The recoveries of SAs on TEPM-DP are much higher than those of commercial C18 and activated carbon. The extraction mechanisms are also elucidated via FT-IR, XPS, and comparative experiments. SIGNIFICANCE: This work reports the first example of design and synthesizing phenazine-based MON in SPE via a simple and rapid solvothermal method. The results reveal the great prospects of TEPM-DP for enriching polar and ionic SAs in complex samples and uncover the potency of phenazine-based MON in sample pretreatment, which will promote the development of MON.

Thiol-yne click post-synthesis of phenylboronic acid-functionalized magnetic cyclodextrin microporous organic network for selective and efficient extraction of antiepileptic drugs.

Owing to their incomplete digestion in the human body and inadequate removal by sewage treatment plants, antiepileptic drugs (AEDs) accumulate in water bodies, potentially affecting the exposed humans and aquatic organisms. Therefore, sensitive and reliable detection methods must be urgently developed for monitoring trace AEDs in environmental water samples. Herein, a novel phenylboronic acid-functionalized magnetic cyclodextrin microporous organic network (Fe3O4@CD-MON-PBA) was designed and synthesized via the thiol-yne click post-modification strategy for selective and efficient magnetic solid-phase extraction (MSPE) of trace AEDs from complex sample matrices through the specific B-N coordination, π-π, hydrogen bonding, electrostatic, and host-guest interactions. Fe3O4@CD-MON-PBA exhibited a large surface area (118.5 m2 g-1), rapid magnetic responsiveness (38.6 emu g-1, 15 s), good stability and reusability (at least 8 times), and abundant binding sites for AEDs. Under optimal extraction conditions, the proposed Fe3O4@CD-MON-PBA-MSPE-HPLC-UV method exhibited a wide linear range (0.5-1000 µg L-1), low limits of detection (0.1-0.5 µg L-1) and quantitation (0.3-2 µg L-1), good anti-interference ability, and large enrichment factors (92.2-104.3 to 92.3-98.0) for four typical AEDs. This work confirmed the feasibility of the thiol-yne click post-synthesis strategy for constructing novel and efficient multifunctional magnetic CD-MONs for sample pretreatment and elucidated the significance of B-N coordination between PBA and N-containing AEDs.

Preparation of cationic microporous organic network for efficient solid-phase extraction of nonsteroidal anti-inflammatory drugs from environmental water and milk samples.

The overuse of nonsteroidal anti-inflammatory drugs (NSAIDs) poses many serious environmental and food safety concerns. Development of effective and sensitive sample pretreatment method for monitoring trace NSAIDs from complex samples is of great significance. Depending on the ionic and aromatic structures of NSAIDs, a cationic microporous organic network (MON) named TEPM-BBDC with large specific surface area, good solvent and thermal stabilities, and numerous interaction sites was designed and prepared for efficient solid-phase extraction (SPE) of four typical NSAIDs (flurbiprofen, ketoprofen, naproxen, and diclofenac sodium) from environmental water and milk samples. By anchoring the ionic groups in the conjugated MON frameworks, the prepared TEPM-BBDC offered good extraction for NSAIDs based on the π-π, hydrophobic, ion exchange, and electrostatic interactions. Under the optimal extraction conditions (initial concentration of each NSAID: 200 g L-1; sample volume: 50 mL; desorption solvent: 1.5 mL of MeOH + 1 % NH3·H2O; sample loading rate: 5 mL min-1; NaCl concentration: 0 mmol L-1; pH = 5), the proposed TEPM-BBDC-SPE-HPLC-UV method owned wide linear range (0.50-1000 g L-1), low limits of detection (0.10-0.40 g L-1), large enrichment factors (92.2-99.2), good precisions (intra-day and inter-day, RSD% = 1.3-7.8 %, n = 6) and reproducibility (column-to-column, RSD% = 8.0 %, n = 3). The developed method also exhibited good recoveries (83.6-113.4 %) for the determination of NSAIDs in river water, lake water and milk samples. This work not only revealed the potential of TEPM-BBDC for SPE of ionic NSAIDs in complex samples, but also highlighted the prospect of ionic MONs in sample pretreatment.

Sacrificial template synthesis of hollow sulfonate group functionalized microporous organic network for efficient solid phase extraction of sulfonamide antibiotics from milk and honey samples.

The highly conjugated and hydrophobic characteristics of microporous organic networks (MONs) have largely impeded their broad applications in sample pretreatment especially for the polar or ionic analytes. In this work, a novel uniform hollow shaped sulfonate group functionalized MON (H-MON-SO3H-2) was synthesized via the sacrificial template method for the efficient solid phase extraction (SPE) of sulfonamides (SAs) from environmental water, milk, and honey samples prior to HPLC analysis. H-MON-SO3H-2 exhibited large specific surface area, penetrable space, good stability, and numerous hydrogen bonding, electrostatic, hydrophobic and π-π interaction sites, allowing sensitive SPE of SAs with wide linear range (0.150-1000 µg L-1), low limit of detection (0.045-0.188 µg L-1), good precisions (intra-day and inter-day RSD < 7.3%, n = 5), large enrichment factors (95.7-98.5), high adsorption capacities (250.4-545.0 mg g-1), and satisfactory reusability (more than 80 times). Moreover, the established method was successfully applied to extract SAs from spiked samples with the recoveries of 86.1-104.3%. This work demonstrated the great potential of H-MON-SO3H-2 in the efficient SPE of trace SAs in complex environmental water and food samples and revealed the prospect of hollow MONs in sample pretreatment.

Fabrication of fluorinated magnetic microporous organic network for selective and efficient extraction of benzoylurea insecticides in tea beverages.

In this work, a novel fluorinated magnetic microporous organic network (Fe3O4@FMON) was exquisitely designed and synthesized for highly efficient and selective magnetic solid phase extraction (MSPE) of fluorinated benzoylurea insecticides (BUs) from complex tea beverage samples. The Fe3O4@FMON exhibited good extraction for BUs via the pre-designed hydrophobic, π-π stacking, hydrogen bonding and specific FF interactions. A sensitive Fe3O4@FMON-based MSPE-HPLC-UV method with wide linear range (0.10-1000 µg L-1, R2 ≥ 0.996), low limits of detection (0.01-0.02 µg L-1), and large enrichment factors (85.6-98.0) for BUs from tea beverage samples was developed. By decorating F elements within MON's networks, the Fe3O4@FMON characterized good hydrophobicity and chemical stability, which could be reused at least 8 times without decrease of recoveries. This work demonstrated the great prospects of Fe3O4@FMON for enriching trace BUs from complex substrates and triggered the potential of FMON for sample pretreatment of fluorinated analytes.

Fabrication of sea urchin shaped polyaniline-modified magnetic microporous organic network for efficient extraction of non-steroidal anti-inflammatory drugs from animal-derived food samples.

In this work, a novel polyaniline-modified magnetic microporous organic network (MMON-PANI) composite was fabricated for effective magnetic solid phase extraction (MSPE) of five typical nonsteroidal anti-inflammatory drugs (NSAIDs) from animal-derived food samples before high performance liquid chromatography (HPLC) detection. The core-shell sea urchin shaped MMON-PANI integrates the merits of Fe3O4, MON, and PANI, exhibiting large specific surface area, rapid magnetic responsiveness, good stability, and multiple binding sites to NSAIDs. Convenient and effective extraction of trace NSAIDs from chicken, beef and pork samples is realized on MMON-PANI via the synergetic π-π, hydrogen bonding, hydrophobic, and electrostatic interactions. Under optimal conditions, the MMON-PANI-MSPE-HPLC-UV method exhibits wide linear ranges (0.2-1000 µg L-1), low limits of detection (0.07-1.7 µg L-1), good precisions (intraday and inter-day RSDs < 5.4 %, n = 3), large enrichment factors (98.6-99.9), and less adsorbent consumption (3 mg). The extraction mechanism and selectivity of MMON-PANI are also evaluated in detail. This work proves the incorporation of PANI onto MMON is an efficient way to promote NSAIDs enrichment and provides a new strategy to synthesize multifunctional MON-based composites in sample pretreatment.

Solvent and monomer regulation synthesis of core-shelled magnetic ß-cyclodextrin microporous organic network for efficient extraction of estrogens in biological samples prior to HPLC analysis.

The abnormal estrogens levels in human body can cause many side effects and diseases, but the quantitative detection of the trace estrogens in complex biological samples still remains great challenge. Here we reported the fabrication of a novel core-shell structured magnetic cyclodextrin microporous organic network (Fe3O4@CD-MON) for rapid magnetic solid phase extraction (MSPE) of four estrogens in human serum and urine samples prior to HPLC-UV determination. The uniform spherical core-shell Fe3O4@CD-MONs was successfully regulated by altering the reactive monomers and solvents. The Fe3O4@CD-MONs owned high specific surface area, good hydrophobicity, large superparamagnetism, and abundant extraction sites for estrogens. Under optimal conditions, the proposed MSPE-HPLC-UV method provided wide linearity range (2.0-400 µg L-1), low limits of detection (0.5-1.0 µg L-1), large enrichment factors (183-198), less adsorbent consumption (3 mg), short extraction time (3 min), and good stability and reusability (at least 8 cycles). The established method had also been successfully applied to the enrichment and detection of four estrogens in serum and urine samples with a recovery of 88.4-105.1 % and a relative standard deviation of 1.0-5.9 %. This work confirmed the feasibility of solvent and monomer regulation synthesis of Fe3O4@CD-MON composites, and revealed the great prospects of magnetic CD-MONs for efficient enrichment of trace estrogens in complex biological samples.

Amide and carboxyl dual-functionalized magnetic microporous organic networks for efficient extraction of cephalosporins.

Cephalosporins (CEFs) are a class of widely used toxic antibiotics. Development of a rapid and sensitive method for detecting trace CEF residues in food samples is still challenging. Herein, we report preparation of an amide and carboxyl groups dual-functionalized core-shelled magnetic microporous organic network MMON-COOH-2CONH for efficient magnetic solid-phase extraction (MSPE) of CEFs from milk powder samples. Under optimal conditions, the established MMON-COOH-2CONH-MSPE-HPLC-UV method owns wide linear range (3-10000 µg kg-1), low limits of detection (1-3 µg kg-1), large enrichment factors (93.9-99.4), low adsorbent consumption (3 mg), and short extraction time (6 min). Synergistic extraction mechanisms of ionic bonding, hydrogen bonding, π-π, and hydrophobic interactions were elucidated by both theoretical density functional theory calculations and experimental data. This study confirms that preparation of dual-functionalized MMONs and introduction of ionic groups are feasible to promote MMONs application in sample pretreatment.

The First Discovery of Marine Polyoxygenated Cembranolides as Potential Agents for the Treatment of Ulcerative Colitis.

Cembranolides are characteristic metabolites in marine soft corals, with complex structures and widespread biological activities. However, seldom has an intensive pharmacological study been done for these intriguing marine natural products. In this work, systematic chemical investigation was performed on Sinularia pedunculata by HSQC-based small molecule accurate recognition technology (SMART), resulting in the isolation and identification of 31 cembrane-type diterpenoids, including six new ones. In the bioassay, several compounds showed significant anti-inflammatory activities on the inhibition of NO production. The structure-activity relationship (SAR) was comprehensively analyzed, and two most bioactive and less toxic compounds 8 and 9 could inhibit inflammation through suppressing NF-κB and MAPK signaling pathways, and reduce the secretion of inflammatory cytokines. In a mouse model of dextran sodium sulfate (DSS)-induced acute colitis, 8 and 9 exhibited good anti-inflammatory effects and the ability to repair the colon epithelium, giving insight into the application of cembranolides as potential ulcerative colitis (UC) agents.