Liquid-phase Mass Spectrometry Research Articles

A new strategy to construct MOF-on-MOF derivatives for the removal of tetracycline hydrochloride from water by activation of peroxymonosulfate

A MOF-on-MOF composite derivative material named ZIF-67@Ce-MOF-600 was designed and synthesized. The preparation of ZIF-67@Ce-MOF-600 was optimized from the aspects of the ratio of metal and ligand, heat-treatment temperature. It was demonstrated by XRD, FT-IR, SEM-EDS and TEM. The optimum conditions for the activation of PMS by ZIF-67@Ce-MOF-600 for the degradation of tetracycline (TC) were investigated by adjusting the catalyst dosage, TC, pH, peoxymonosulfate (PMS) concentration, and different kinds of water, co-existing anions and pollution. Under optimal conditions (20 mg catalysts and 50 mg PMS added) in 100 mL of tetracyclines (TC) solvent (20 mg TC/L), the removal rate could reach up to 99.2% and after five cycles was 70.5%. The EPR results indicated the presence of free radicals and non-free radical, among which free radicals intended to play a major role in the degradation process. Its possible degradation pathways and attack sites were analyzed by liquid-phase mass spectrometry and DFT analysis.

Preparation of a Co3O4/Bi2MoO6 P‐N‐Type Heterojunction with Enhanced Photocatalytic Activity and Synergistic PMS Enrofloxacin Degradation

AbstractIn this work, Co3O4/Bi2MoO6 p‐n‐type heterojunctions were successfully fabricated via a hydrothermal method combined with in‐situ deposition. The as‐prepared samples were systematically characterized by means of SEM, TEM, XPS, XRD, etc. Through the synergistic effect of PMS (peroxosulfate monosalt), the obtained composite CB‐2 has a superior degradation performance of enrofloxacin under visible light irradiation, and the degradation rate of enrofloxacin reaches 87.84 % within 30 min. The reaction process of enrofloxacin degradation was analyzed by 3D EEM (exception emission matrix spectrum) and LC–MS (liquid phase mass spectrometry). The influence of the reaction system on EFA degradation efficiency without PMS synergy and light was studied. The kind of free radical was determined from the outcome of the EPR and free radical capture experiment. Benefiting from the construction of the p‐n heterojunction system and the activation of the PMS, the photogenerated carriers of the Co3O4/Bi2MoO6 composite can be fully separated and transferred to produce active species with higher oxidative properties. Based on this, the photocatalytic mechanism of Co3O4/Bi2MoO6/PMS was explored.

Analysis of flavonoid metabolism of compounds in succulent fruits and leaves of three different colors of Rosaceae

Red flesh apple (Malus pumila var. medzwetzkyana Dieck), purple leaf plum (Prunus cerasifera Ehrhar f), and purple leaf peach (Prunus persica ‘Atropurpurea’) are significant ornamental plants within the Rosaceae family. The coloration of their fruits and leaves is crucial in their appearance and nutritional quality. However, qualitative and quantitative studies on flavonoids in the succulent fruits and leaves of multicolored Rosaceae plants are lacking. To unveil the diversity and variety-specificity of flavonoids in these three varieties, we conducted a comparative analysis of flavonoid metabolic components using ultra-high-performance liquid phase mass spectrometry (UPLC-MS/MS). The results revealed the detection of 311 metabolites, including 47 flavonoids, 105 flavonols, 16 chalcones, 37 dihydroflavonoids, 8 dihydroflavonols, 30 anthocyanins, 14 flavonoid carbon glycosides, 23 flavanols, 8 isoflavones, 11 tannins, and 12 proanthocyanidins. Notably, although the purple plum and peach leaves exhibited distinct anthocyanin compounds, paeoniflorin and corythrin glycosides were common but displayed varying glycosylation levels. While the green purple leaf peach fruit (PEF) and red flesh apple leaf (AL) possessed the lowest anthocyanin content, they exhibited the highest total flavonoid content. Conversely, the red flesh apple fruit (AF) displayed the highest anthocyanin content and a diverse range of anthocyanin glycosylation modifications, indicating that anthocyanins predominantly influenced the fruit's color. Purple PLF, PLL, and PEL showcased varying concentrations of anthocyanins, suggesting that their colors result from the co-color interaction between specific types of anthocyanins and secondary metabolites, such as flavonols, flavonoids, and dihydroflavonoids. This study provides novel insights into the variations in tissue metabolites among Rosaceae plants with distinct fruit and leaf colors.

Construction of novel surfactant-modified metal-organic framework adenine-UiO-66 with enhanced piezocatalytic degradation of diclofenac sodium

Piezoelectric materials can harvest mechanical energy and convert it into electrical energy, which have lately become highly effective catalysts to sustainable eliminate pollutants. Here, by adding different surfactants to metal-organic framework adenine-UiO-66 (AD-U) materials, the metal-organic framework adenine-UiO-66 (AD-U-S) modified by sodium dodecyl benzene sulfonate (SDBS) and the metal-organic framework adenine-UiO-66 (AD-U-C) modified by cetyltrimethylammonium bromide (CTAB) were prepared for the first time. With the antibiotic diclofenac sodium (DCF) as the target pollutant, the degradation efficiencies of AD-U-S (0.30) and AD-U-C (0.30) were 98 % and 78 % in 30 min, respectively. Specially, the reaction rate constant of AD-U-S (0.30) is 3.5 times that of AD-U-C (0.30). The performance improvement is due to the larger specific surface area, stronger ferroelectric properties, enhanced oxidation capability and higher charge transfer efficiency of AD-U-S (0.30) than that of AD-U-C (0.30). The capture experiments showed that ‧OH and h+ were the main active species on AD-U-S (0.30) and AD-U-C (0.30) during the removal of DCF. In addition, possible pathways for DCF piezodegradation were obtained by liquid-phase mass spectrometry and DFT calculations. This study is benefit to promote the development of piezocatalytic technology for wastewater treatment.

Ampelopsis japonica aqueous extract improves ovulatory dysfunction in PCOS by modulating lipid metabolism

Polycystic ovary syndrome (PCOS) is a highly prevalent endocrine and metabolic disorder that is closely associated with the proliferation and apoptosis of ovarian granulosa cells (GCs). Ampelopsis japonica (AJ) is the dried tuberous root of Ampelopsis japonica (Thunb.) Makino (A. japonica), with anti-inflammatory, antioxidant, antibacterial, antiviral, wound-healing, and antitumor properties; however, it is unclear whether this herb has a therapeutic effect on PCOS. Therefore, this study aimed to investigate the pharmacological effect of AJ on PCOS and reveal its potential mechanism of action. A PCOS rat model was established using letrozole. After establishing the PCOS model, the rats received oral treatment of AJ and Diane-35 (Positive drug: ethinylestradiol + cyproterone tablets) for 2 weeks. Lipidomics was conducted using liquid-phase mass spectrometry and chromatography. AJ significantly regulated serum hormone levels and attenuated pathological variants in the ovaries of rats with PCOS. Furthermore, AJ significantly reduced the apoptotic rate of ovarian GCs. Lipidomic analysis revealed that AJ modulated glycerolipid and glycerophospholipid metabolic pathways mediated by lipoprotein lipase (Lpl), diacylglycerol choline phosphotransferase (Chpt1), and choline/ethanolamine phosphotransferase (Cept1). Therefore, we established that AJ may reduce ovarian GC apoptosis by modulating lipid metabolism, ultimately improving ovulatory dysfunction in PCOS. Therefore, AJ is a novel candidate for PCOS treatment.

Enhanced degradation of chloramphenicol via heterogeneous activation of peroxymonosulfate by Fe3O4 and gallic acid

In this study, we demonstrated the effective degradation of wide-spectrum antibiotic chloramphenicol (CAP) by Fe3O4/peroxymonosulfate (PMS) system modified by gallic acid (GA). GA/Fe3O4/PMS showed a substantially higher degradation rate (77.6%) than Fe3O4/PMS (8.3%). The active components were detected by electron spin-resonance spectroscopy (ESR) and the quenching experiments. The results showed that the hydroxyl radical (HO•) was the main reason for the degradation of CAP. In the GA/Fe3O4/PMS system, the trace amount of dissolved iron ion were not the main species that activated PMS. Surface characterization and theoretical simulations showed that Fe atoms on Fe3O4 were responsible for PMS activation rather than a homogenous reaction. Five probable CAP degradation pathways were identified by density functional theory (DFT) calculations and liquid-phase mass spectrometry. Finally, the reusability of Fe3O4 was measured, and the GA/Fe3O4/PMS system maintained high efficiency after 5 times applications. The total organic carbon (TOC) removal rate reached 46.5% after reacting for 12 h. The gallic acid effectively promotes the circulation of Fe(II)/Fe(III) on solid surfaces and enhanced the degradation capacity of the original system. The research proposed a new way of directly employing plant polyphenols to boost the degradation ability of contaminants in heterogeneous systems.

Construction of type-II scheme SnO@HfC photocatalyst for bisphenol A degradation via peroxymonosulfate activation; DFT and self-cleaning analysis

In this study, novel stannous oxide@hafnium carbide (SnO@HfC) nanocomposite was successfully manufactured by an appropriate hydrothermal scheme which was utilized for the photocatalytic degradation of BPA by stimulation of peroxymonosulfate (PMS) and self-cleaning application. Numerous methods were applied for the characterization of photocatalyst and demonstrated the successful preparation of SnO@HfC nanocomposite. The crystal structures, band structures and density of states for SnO and HfC were explored by DFT analysis. The amazing PMS stimulation performance of SnO@HfC nanocomposite originated from the establishment of a heterojunction, which led to the enhancement of the light response aptitude and the electron conduction competence of the composite. BPA was degraded by 0.75 g/L PMS and SnO@HfC at neutral pH during the period of 60 min. In order to identify active groups in the reaction procedure, quenching experiments and electron paramagnetic resonance (EPR) approaches were also used. In the subsequent active species scavenging assays, where sulfate radicals, hydroxyl radicals, holes, and superoxide radicals were engaged in the degradation of BPA. While, liquid phase mass spectrometry (LC-MS) was used to pinpoint the intermediate metabolites in the course of degradation. SnO@HfC/PMS/light system delivered excellent TOC removal efficiency and less ions leaching. The SnO@HfC nanocomposite proved good durability and reusability in continuous cycle tests along with excellent self-cleaning function on the glass substrate. The SnO@HfC nanocomposite performs admirably in terms of self-cleaning application. The SnO@HfC nanocomposite is expected to be used in the future for the treatment of wastewater that contains pharmaceuticals due to its superior stability and reusability after five consecutive cycles.

Identification the key factor of pulmonary fibrosis following silica nanoparticles exposure based on bioinformatics analysis

Objective: To investigate the main mechanisms of pulmonary fibrosis following silica nanoparticles (SiNPs) exposure through constructing the macrophage-fibroblast model in vitro, which simulated the process of pulmonary fibrosis. Methods: In January 2021, human mononuclear leukemia cells (THP-1) were treated with 0, 25, 50, 100 μg/ml SiNPs for 24 h. The supernatant of THP-1 cells was collected and applied to human embryonic lung fibroblast cells (MRC-5) which divided into control and low, medium and high dose groups at the logarithmic growth stage for 24 h. MRC-5 cell viability was detected by CCK8. The hydroxyproline (Hyp), interleukin 6 (IL-6), interleukin 1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) expression were detected in the supernatants of MRC-5. The changed proteins were detected by liquid-phase mass spectrometry in high dose group. GeneCard database were applied to identity the differential pulmonary fibrosis proteins in high dose group. Gene Ontology (GO) was performed to identity the key biological process in differential pulmonary fibrosis proteins of high dose group. The String database was used to construct the protein-protein interactions (PPI) network of differential pulmonary fibrosis proteins. The APP of CytoHubba was applied to calculate the key protein of differential pulmonary fibrosis proteins in PPI network. Correlation coefficients between key differential pulmonary fibrosis proteins were calculated using Pearson correlation analysis. Western blotting was applied to detect the expression of key proteins of differential pulmonary fibrosis proteins in different groups. Results: CCK8 results showed that MRC-5 cell viability was increasing in low, medium and high dose groups compared with control group (P<0.05). The expression levels of Hyp and IL-1β in different group were increased compared with control group, the expression levels of IL-6 and TNF-α were increased in high dose group compared with control group (P<0.05). GeneCard database identified 26 differential pulmonary fibrosis proteins, which were mainly involved in extracellular matrix hydrolysis, cell inflammatory response, tissue repair, cell proliferation, inflammation response by GO analysis. The APP of CytoHubba was calculated that matrix metalloproteinase 9 (MMP9) and tissue inhibitor metalloproteinase 1 (TIMP1) played an important role in PPI network. The results of correlation analysis showed that MMP9 was correlated with the expression of matrix metalloproteinase 1 (MMP1), matrix metalloproteinase 3 (MMP3), TIMP1 and epidermal growth factor receptor (EGFR) (r=0.97, 0.98, 0.94, 0.93, P<0.05). Western blotting results showed that TIMP1 protein expression was increased in low, medium and high dose groups, while MMP9 protein expression was increased only in high dose group (P<0.05) . Conclusion: Differential expression proteins related with pulmonary fibrosis in MRC-5 cells mainly regulate biological processes of extracellular matrix hydrolysis, tissue repair, and cellular inflammation response following SiNPs exposure. MMP9 and TIMP1 may be the key proteins, which affected the fibrosis process in vitro pulmonary fibrosis model.

Enhanced activation performance of peroxymonosulfate by NiCo2O4/SnO2 composite for metronidazole degradation under visible light

In this study, a NiCo2O4/SnO2 complex was successfully synthesized by a convenient hydrothermal method and used for the catalytic degradation of metronidazole (MNZ) by activating peroxymonosulfate (PMS). The physicochemical properties of NiCo2O4/SnO2 were identified by a series of characterization methods. The remarkable PMS activation performance of NiCo2O4/SnO2 originated from the formation of a heterojunction between NiCo2O4 and SnO2, which led to the improvement of the light response ability and the electron conduction efficiency of the composite. The composite catalyst displayed almost 100 % MNZ degradation efficiency within 30 min under visible light. The degradation efficiency of MNZ can be maintained in a wide pH range (3−11). Furthermore, the effect of catalyst dosage, PMS concentration and MNZ concentration on the catalytic process were investigated by changing the experimental parameters. The various anions and different water substrates had only a minor influence on the degradation process of MNZ. In addition, quenching experiments and electron paramagnetic resonance techniques were employed to detect active groups in the reaction process. The results showed that superoxide radicals (O2•-), hydroxyl radicals (OH•), singlet oxygen (1O2), and sulfate radicals (SO4•-) were the main causes of MNZ degradation. Meanwhile, the liquid phase mass spectrometry (LCMS) and Toxicity Estimation Software Tool (T.E.S.T) were utilized to identify the intermediate products and their biological toxicity in the degradation process, and demonstrating a significant decline of biotoxicity compared with MNZ. Generally, this work will provide a new feasible scheme for the effective treatment of organic contaminants in water.

Effect of Carbon Ion Radiation Induces Bystander Effect on Metastasis of A549 Cells and Metabonomic Correlation Analysis.

ObjectiveTo analyze the effect of carbon ion (12C6+) radiation may induce bystander effect on A549 cell metastasis and metabonomics.MethodsA549 cell was irradiated with carbon ion to establish the clone survival model and the transwell matrix assay was applied to measure the effect of carbon ion on cell viability, migration, and invasion, respectively. Normal human embryonic lung fibroblasts (WI-38) were irradiated with carbon ions of 0 and 2 Gy and then transferred to A549 cell co-culture medium for 24 h. The migration and invasion of A549 cells were detected by the Transwell chamber. The analysis of metabonomic information in transfer medium by liquid phase mass spectrometry (LC-MS), The differential molecules were obtained by principal pomponent analysis (PCA) and the target proteins of significant differences (p = 1.7 × 10−3) obtained by combining with the STICH database. KEGG pathway was used to analyze the enrichment of the target protein pathway.ResultsCompared with 0 Gy, the colony formation, migration, and invasion of A549 cells were significantly inhibited by carbon ion 2 and 4 Gy irradiation, while the inhibitory effect was not significant after 1 Gy irradiation. Compared with 0 Gy, the culture medium 24 h after carbon ion 2 Gy irradiation significantly inhibited the metastasis of tumor cells (p = 0.03). LC-MS analysis showed that 23 differential metabolites were obtained in the cell culture medium 24 h after carbon ion 0 and 2 Gy irradiation (9 up-regulated and 14 down-regulated). Among them, two were up-regulated and two down-regulated (p = 2.9 × 10−3). 41 target proteins were corresponding to these four differential molecules. Through the analysis of the KEGG signal pathway, it was found that these target molecules were mainly enriched in purine metabolism, tyrosine metabolism, cysteine and methionine metabolism, peroxisome, and carbon metabolism. Neuroactive ligand-receptor interaction, calcium signaling pathway, arachidonic acid metabolism, and Fc epsilon RI signaling pathway.ConclusionThe bystander effect induced by 2 Gy carbon ion radiation inhibits the metastasis of tumor cells, which indicates that carbon ions may change the metabolites of irradiated cells, so that it may indirectly affect the metabolism of tumor cell growth microenvironment, thus inhibiting the metastasis of malignant tumor cells.

Super stable capillary electrophoresis: theory and examples

Capillary electrophoresis is often plagued by unstable and unrepeatable results. In this paper, some novel modes are derived theoretically and illustrated by separation examples, as expected these modes can resist the change of some conditions under certain prerequisites and obtain super stable electropherograms. They are weighted mobility spectrometry, migrated charge spectrometry, charge density spectrometry, molar charge density spectrometry, diffusion coefficient spectrometry, liquid-phase mass spectrometry, and their ratio spectrometry. The first four are real-time measurement modes while the others are post-experimental modes. These modes need to develop new devices and algorithm, but they are all highly promising and worth of further exploitation.

Extraction, Partial Identification and Bioactivities of Total Flavonoids from Carex meyeriana Kunth

To date, knowledge associated with extraction, chemical constituents and bioactivities of Total Flavonoids from Carex meyeriana Kunth (TFCMK) that remains unclear. Therefore, this paper was designed to optimize the ethanol reflux extraction method by response surface methodology and determine the chemical constituents by Liquid Phase-Mass Spectrometry (HPLC-MS); additionally, the bioactivities including antioxidant, antibacterial and hemolysis test were also explored. The maximum TFCMK extraction yield of 6.248%±0.016% was obtained under the optimal conditions as follows: Ethanol concentration 50%, ratio of liquid-to-solid 31 mL/g, extraction time 91 min and extraction temperature 71°C. Meanwhile, 9 compounds of TFCMK were identified by using LP-MS for the first time. In addition, TFCMK showed higher antioxidant activity compared with vitamin C, as evidenced by the lower EC50 or IC50 of TFCMK (reducing power assay: 0.125±0.025 mg/mL, DPPH radicals: 0.28±0.031, ABTS+ radicals:0.012±0.005, hydroxyl radicals: 0.028±0.008 mg/mL; The EC50 or IC50 of VC 0.156±0.012, 0.059±0.019, 0.068±0.024 and 0.032±0.007 mg/mL, respectively.). Broth microdilution assays had demonstrated that the minimal inhibitory concentrations (MICs) of TFCMK on Bacillus pumilus, Bacillus subtilis and Escherichia coli were 0.625±0.0032, 1.250±0.0216 and 5.000±0.0205 mg/mL, respectively. Besides, the hemolysis rate (less than 5%) in vitro implied that TFCMK possessed a good blood compatibility. In summary, this paper provides evidences that TFCMK might be applied as an antioxidant and antibacterial agent in the pharmaceutical and chemical industries.