High-performance Liquid Chromatography-mass Spectrometry Analysis Research Articles

Targeted Discovery of Glycosylated Natural Products by Tailoring Enzyme-Guided Genome Mining and MS-Based Metabolome Analysis.

Glycosides make up a biomedically important class of secondary metabolites. Most naturally occurring glycosides were isolated from plants and bacteria; however, the chemical diversity of glycosylated natural products in fungi remains largely unexplored. Herein, we present a paradigm to specifically discover diverse and bioactive glycosylated natural products from fungi by combining tailoring enzyme-guided genome mining with mass spectrometry (MS)-based metabolome analysis. Through in vivo genes deletion and heterologous expression, the first fungal C-glycosyltransferase AuCGT involved in the biosynthesis of stromemycin was identified from Aspergillus ustus. Subsequent homology-based genome mining for fungal glycosyltransferases by using AuCGT as a probe revealed a variety of biosynthetic gene clusters (BGCs) containing its homologues in diverse fungi, of which the glycoside-producing capability was corroborated by high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. Consequently, 28 fungal aromatic polyketide C/O-glycosides, including 20 new compounds, were efficiently discovered and isolated from the three selected fungi. Moreover, several novel fungal C/O-glycosyltransferases, especially three novel α-pyrone C-glycosyltransferases, were functionally characterized and verified in the biosynthesis of these glycosides. In addition, a proof of principle for combinatorial biosynthesis was applied to design the production of unnatural glycosides in Aspergillus nidulans. Notably, the newly discovered glycosides exhibited significant antiviral, antibacterial, and antidiabetic activities. Our work demonstrates the promise of tailoring enzyme-guided genome-mining approach for the targeted discovery of fungal glycosides and promotes the exploration of a broader chemical space for natural products with a target structural motif in microbial genomes.

Near UV Photodegradation Mechanisms of Amino Acid Excipients: Formation of the Carbon Dioxide Radical Anion from Aspartate and Fe(III).

Carbon dioxide radical anion (•CO2-) is a powerful reducing agent that can reduce protein disulfide bonds and convert molecular oxygen to superoxide. Therefore, the generation of •CO2- can be detrimental to pharmaceutical formulations. Iron is among the most prevalent impurities in formulations, where Fe(III) chelates of histidine (His) can produce •CO2- upon exposure to near-UV light (Zhang and Schöneich, Eur. J. Pharm. Biopharm. 2023, 190, 231-241). Here, we monitor by spin-trapping in combination with electron paramagnetic resonance spectroscopy and/or high-performance liquid chromatography-mass spectrometry analysis the photochemical formation of •CO2- for a series of common amino acid excipients, including arginine (Arg), methionine (Met), proline (Pro), glutamic acid (Glu), glycine (Gly), aspartic acid (Asp), and lysine (Lys). Our results indicate that in the presence of Fe(III), Asp, and Glu produce significant yields of •CO2- under photoirradiation with near-UV light. Notably, Asp demonstrates the highest efficiency of •CO2- generation compared with that of the other amino acid excipients. Stable isotope labeling indicates that •CO2- exclusively originates from the α-carboxyl group of Asp. Mechanistic studies reveal two possible pathways for •CO2- formation, which involve either a β-carboxyl radical or an amino radical cation intermediate.

A Bronze Age lip-paint from southeastern Iran

A small chlorite vial, discovered among numerous artifacts looted and recovered in the Jiroft region of Kerman province, southeastern Iran, contains a deep red cosmetic preparation that is likely a lip-coloring paint or paste. Through analytical research involving XRD (X-ray diffraction), SEM–EDS (scanning electron microscopy-energy-dispersive spectroscopy), and HPLC–MS (high-performance liquid chromatography-mass spectrometry) analyses, the mineral components of the reddish substance were identified as hematite, darkened with manganite and braunite, and traces of galena and anglesite, mixed with vegetal waxes and other organic substances. The mixture, thus observed, bears a striking resemblance to the recipes of contemporary lipsticks. We also report the first radiocarbon date ever obtained from a Bronze age cosmetic in the ancient Near East: results place the pigment in the early 2nd millennium BCE, a date compatible with several mentions of the powerful eastern-iranian civilization of Marḫaši in coeval cuneiform texts of Mesopotamia, as well as with its currently emerging archaeological picture.

Analysis of novel In2S3/polyimide Z-scheme heterojunctions with enhanced photocatalytic target compound degradation efficiency

In this study, In2S3/PI Z-scheme heterojunctions composite photocatalysts were synthesized via a hydrothermal technique and employed to degrade tetracycline hydrochloride under the action of visible light. The enhancement of their performance was achieved by combining organic and metallic materials. The In2S3/PI heterojunction with 20 wt% In (20In2S3/PI), demonstrated the highest efficiency in target compound (TC) degradation, with a rate of 88%, i.e., 86% and 38% higher than that of PI and In2S3, respectively, over 180 min. This remarkable photocatalytic performance was due to the enhanced charge separation and decreased electron-hole pair recombination, through the formation of a diverse structure. The high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, radical trapping, and electron paramagnetic resonance spectroscopy analyses verified the above speculation. Compared to pure PI and In2S3, the composite photocatalyst exhibited a superior generation of active species, i.e., ∙O2− and h+, along with a higher capacity for mineralization. Furthermore, high-performance liquid chromatography–mass spectrometry analysis was performed to examine the possible pathways for the photocatalytic degradation of TC by the In2S3/PI composites. The findings of this study provide a novel approach to TC degradation.

Development of a reliable method for determination of N-nitrosamines in medicines using disposable pipette extraction and HPLC-MS analysis.

This study outlines the development and optimization of an analytical method using Disposable Pipette Extraction (DPX) followed by high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis to determine NAs in medicines. HPLC-MS analysis utilized a reversed-phase and positive mode electrospray ion source. DPX parameters were optimized through univariate and multivariate analyses, including extraction phase, desorption solvent, sample pH, equilibrium time, and extraction/desorption cycles. The optimized conditions included a C18 extraction phase, methanol desorption solvent, pH at 7, an equilibrium time of 30 seconds, 2 extraction cycles, and 5 desorption cycles. Considering this method, it was possible to achieve a sample preparation step for the analysis of NAs in medicines using a minimal amount of extraction phase, sample, and desorption solvent. Furthermore, the total extraction procedure enables the extraction of NAs in around 4 minutes with NA recovery up to 98%. Analytical performance demonstrated precision and accuracy below 15% and a quantification limit of 1 ng mL-1, meeting validation requirements set by regulations worldwide. Thus, the DPX/HPLC-MS technique offers a faster and cost-effective method for analyzing NAs in medicines compared to traditional approaches. Besides, this method reduces solvent consumption and residue generation, enhancing environmental sustainability according to green chemistry principles.

Identification of the Bioactive Compounds of Raw and Honey-Processed Farfarae Flos by High-Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) with the Spectrum-Effect Relationship and Chemometrics

Farfarae Flos (FF), also known as “Kuandonghua” in Chinese, is a commonly used traditional Chinese medicine (TCM) with various therapeutic properties, including antitussive, expectorant, antioxidant, and anti-inflammatory effects. Despite the widespread consumption of processed FF, there has been limited progress in improving quality control measures for both raw FF and honey-processed Farfarae Flos (PFF). This study aimed to establish a comprehensive strategy for quality evaluation and distinguish between FF and PFF by integrating high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis with chemometric techniques. Additionally, the antioxidant activities of FF and PFF were assessed using radical-scavenging experiments. The spectrum-effect relationship is the association of chemical composition information of the fingerprint with antioxidant activity, which was used to predict the primary active components that influence the antioxidant activity of FF. The results indicated that FF and PFF samples showed a clear distinction, and the most potent pharmacologically active ingredients were hyperoside, quercetin, caffeic acid, isoquercitrin, neochlorogenic acid, rutin, cryptochlorogenic acid, and isochlorogenic acid C. Moreover, the comprehensive efficacy of the honey-processed FF was better than for raw FF. In conclusion, the findings of this study provide a scientific foundation for future evaluation of the quality, further research, and practical use of FF herbs.

Interaction of Clematis flammula extracts with membrane models: characterization of anti-inflammatory and antibacterial activities

The present study aimed at elucidating the anti-inflammatory, antioxidant, and antibacterial mechanisms of Clematis flammula (CF) leaf extracts. Methodologically, antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl and ferric ion reducing antioxidant power assays, and antibacterial activity was assessed using Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) cell cultures. Anti-inflammatory potency was evaluated through cyclooxygenase and trypsin inhibitory activities. Moreover, the anti-inflammatory and antibacterial mechanisms of the active extracts were elucidated using two membrane models: erythrocytes and liposomes. The phenolic compounds in the extracts were identified using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Ethyl acetate extract inhibited S. aureus growth at a minimum inhibitory concentration of 78 µg/mL, possibly due to its lytic activity of liposomes (56.75 ± 0.54%). Additionally, the extract presented the best anti-trypsin activity (IC50 =7.67 ± 0.61 µg/mL) and inhibited cyclooxygenase activity (IC50 = 594.33 ± 11.15 µg/mL), probably related to its high polyphenol content (192.64 ± 1.55 mg GAE/g E). HPLC-MS analysis revealed the presence of flavones and flavonols. Conclusively, the results of this study suggest that CF extracts exert anti-inflammatory and antibacterial effects by inhibiting cyclooxygenase and trypsin activities and altering bacterial cell membrane, suggesting the potential of CF in the treatment of bacterial infections and inflammatory disorders.

Nematicidal effect of Beauveria species and the mycotoxin beauvericin against pinewood nematode Bursaphelenchus xylophilus

Introduction and main objectiveBursaphelenchus xylophilus, commonly known as pine wood nematode (PWN), is considered one of the greatest threats to European and Asian pines. Regarding its management, most efforts have been directed toward control measures for the major vector (Monochamus spp.) and screening for genetic resistance in its hosts. However, an integrated pest management strategy which also implements pinewood nematode control is currently lacking. The aim of this study was to evaluate the nematicidal effect of two Beauveria species, a genus well known for its entomopathogenic activity.Summary methodologyFor this purpose, in vitro antagonism tests of fungi (Beauveria bassiana and B. pseudobassiana) and the mycotoxin beauvericin (C45H57N3O9) on B. xylophilus populations were conducted. Finally, the production of beauvericin in B. bassiana and B. pseudobassiana strains was quantified by high-performance liquid chromatography - mass spectrometry (HPLC-MS).Results and discussionBoth the B. bassiana and B. pseudobassiana fungal species and the mycotoxin beauvericin showed a clear nematicidal effect on B. xylophilus populations, substantially reducing their survival rate and even attaining 100% mortality in one case. HPLC-MS analysis confirmed and quantified the production of beauvericin by B. bassiana and demonstrated for the first-time beauvericin production in B. pseudobassiana.Final conclusionThese findings highlight the potential of Beauveria species and the mycotoxin beauvericin to be implemented in an integrated pest management strategy to control both nematode and vector.

From Kiwi Peels’ “End-of-Life” to Gold Nanoparticles: the Upcycling of a Waste

Following a green approach, kiwi peels (a waste) were washed in hot water to obtain a water-based polyphenolic extract (KPWW) used to reduce Au3+ (coming from a HAuCl4 water-based solution) for forming gold nanoparticles (AuNPs). Indeed, KPWW, as shown after performing high-performance liquid chromatography-mass spectrometry (HPLC/MS-MS) analysis, is mainly composed by different polyphenols acting as reductant agents, accomplishing a red-ox reaction and decorating the AuNPs-KPWW surface. Spectroscopic and morphologic techniques were used in synergy for investigating the AuNPs-KPWW main features. Polyhedral-shaped plasmonic nanoparticles with a mean size of 30±10 nm and a negative charge of −40 mV were thus obtained. The AuNPs’ stability was assessed under different working conditions, investigating the role of ionic strength, pH, and temperature. The photostability was also assessed by irradiating AuNPs-KPWW with a solar simulator lamp. Both temperature and solar light did not perturb AuNPs-KPWW. Thanks to the presence of polyphenols, the antioxidant and skin-lightening properties were positively demonstrated. Moreover, the protective role of AuNPs in scavenging H2O2 and ·OH was also investigated by inhibiting the oxidation of a biomolecule. The sunscreen ability of AuNPs-KPWW was also estimated, and the theoretical calculation of the sun protection factor (SPF) was determined. Finally, the AuNPs-KPWW biocompatibility was tested on endothelial colony-forming cells and normal dermal fibroblasts as human cell lines, revealing that AuNPs-KPWW did not affect cell viability and did not alter cell morphology, demonstrating their safety and their potential application in nanomedicine.

Nitrogen self-doped chitosan carbon aerogel integrating with CoAl-LDH for ultra-efficient sulfamethoxazole degradation based on PS-AOPs: From batch to continuous process

Nitrogen self-doped chitosan carbon aerogel (NCCA) integrating with CoAl layered double hydroxide (CoAl-LDH) was successfully fabricated and utilized for the ultra-efficient activation of peroxymonosulfate (PMS) toward sulfamethoxazole (SMX) degradation. And the NCCA/CoAl-LDH-2 catalyst possessed the highest catalytic activity with 97.5% of SMX degradation efficiency in 5 min and 74.8% of total organic carbon (TOC) removal efficiency in 30 min, may being on account of the synergistic interaction between NCCA and CoAl-LDH. Additionally, the NCCA/CoAl-LDH-2 catalyst not only had good reusability and stability, but also could realize continuous degradation of SMX solutions via a fixed-bed reactor. Furthermore, the results of quenching tests, electrochemical measurements as well as electron paramagnetic resonance (EPR) analysis demonstrated that both non-radical and radical processes participated in the SMX degradation, in which the latter played a predominant role. X-ray photoelectron spectroscopy (XPS) corroborated that the main active sites were the CO groups and graphitic N of NCCA, and the Co3+/Co2+ redox cycle of CoAl-LDH. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis and density functional theory (DFT) calculation containing the laplacian bond order (LBO) and Fukui index were carried out to deeply explore the reasonable SMX degradation pathways. This current study provided a theoretical basis to design an efficient PMS activation system toward continuous antibiotics degradation.

Identification of the Key Active Pharmaceutical Ingredients of Yishen Qutong Granule, A Chinese Medicine Formula, In The Treatment of Primary Lung Cancer.

Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. Traditional Chinese medicine (TCM) reportedly has potential therapeutic effects against LC. This study aimed to investigate the antitumor efficacy of Yishen Qutong granule (YSQTG) in primary LC treatment, to identify its key active pharmaceutical ingredients (APIs), and to explore its possible mechanism of action. The antitumor role of YSQTG was validated via cell function assays and a xenograft tumor model. Then, high-performance liquid chromatography-mass spectrometry (HPLC-MS) was performed to determine the objective precipitation components of YSQTG, followed by target prediction through reference to databases. Subsequently, the proportion of the predicted targets that underwent actual changes was identified via RNA-sequencing. Enrichment analysis was performed to explore the possible mechanisms of action. Hub genes were screened, and western blotting was used to verify their protein expression levels to identify the core target. Molecular docking between the active compounds and the verified core target was performed, combined with an evaluation of the potential efficacy of candidate compounds using meta-analysis to screen the candidate key APIs. Experiments confirmed that YSQTG could inhibit LC cell proliferation, induce apoptosis in vitro, and inhibit lung tumor growth in vivo. HPLC-MS, RNA-seq, and enrichment analysis showed that oxidative stress-related pathways were the possible mechanism of YSQTG in primary LC treatment. Western blot verification indicated that heme oxygenase 1 (HMOX1, HO-1) could be the core target. Molecular docking and meta-analysis suggested that genistein and quercetin were the candidate key APIs. YSQTG and its active ingredients, genistein and quercetin, may have therapeutic effects against LC through their action on the downregulation of oxidative stress-related HMOX1 protein expression.

Yuhong ointment ameliorates inflammatory responses and wound healing in scalded mice.

Yuhong ointment (YHO) is famous for its efficacy in clearing away heat and dampness, reducing swelling and relieving pain, and it has been used for more than 600 years. Scalding damages the skin's defense function, resulting in a large number of necrotic tissues and cells on the wound surface, which favors bacterial growth and inflammation. If the inflammation reaction is not controlled on time, it may lead to reduced immunity and cause complications such as infection. Yuhong ointment can promote wound healing in scalded mice, but its potential pharmacological mechanism is still unclear. This study focused on identifying the active ingredients of YHO and on investigating the performance of YHO in terms of anti-inflammatory activity and scald wound healing activity. High-performance liquid chromatography (HPLC) and high-performance liquid chromatography-mass spectrometry (HPLC-MS) were performed to identify the active ingredients of YHO. The performance of transdermal delivery of YHO was studied via HPLC for analyzing the ingredients of the exposed skin liquid of mice. Enzyme-linked immunosorbent assay (ELISA) analysis, immunohistochemistry, and real-time fluorescence quantitative PCR (qRT-PCR) were used to investigate the anti-inflammatory and scald wound healing activity of YHO. A total of 41 components of YHO were identified via HPLC and HPLC-MS for the first time. In the transdermal delivery experiment, the cumulative amounts of chlorogenic acid, sesamol, ferulic acid, and L-shikonin were calculated to be 342.28, 567.89, 384.54, and 528.67 μg/cm2, respectively. Pharmacological activity experiments indicated that these four kinds of drugs exhibited different degrees of therapeutic effects on scald. Specifically, YHO high-dose (YHO-H) group showed better therapeutic ability (P < 0.01) than FN and MB group. Furthermore, the immune function of the YHO group was enhanced due to the continuous increment of the levels of Hydroxyproline (HYP), Immunoglobulin G (IgG), and vascular endothelial growth factor (VEGF) and simultaneous decrement of the levels of TNF-α, TNF-β, IL-10, and IL-6 in the skin wound. Histological results showed that the thickening of skin tissue was alleviated after treatment with YHO. Moreover, the expression of substance P (SP), calcitonin gene related peptide (CGRP) and transient receptor potential vanilloid-1 (TRPV1) was inhibited, and the expression of VEGF was promoted by YHO (P < 0.01). The qRT-PCR test results indicated that the YHO group exhibited better inhibitory effect on interleukin 6 (IL-6), interleukin 10 (IL-10), transforming growth factor-beta (TGF-β), and Smad-3 mRNA expression levels than the other groups. In this work, the active ingredients of YHO were identified via HPLC and HPLC-MS analysis. Importantly, YHO showed great advantages in transdermal delivery and scald wound healing, which can be attributed to the both anti-inflammatory and tissue regeneration mechanisms. Therefore, this work not only identified the active ingredients of YHO but also revealed the potential pharmacological mechanism of YHO for the healing of scald.

Antioxidant Properties, Bioactive Compounds Contents, and Chemical Characterization of Two Wild Edible Mushroom Species from Morocco: Paralepista flaccida (Sowerby) Vizzini and Lepista nuda (Bull.) Cooke.

Mushrooms have been consumed for centuries and have recently gained more popularity as an important source of nutritional and pharmaceutical compounds. As part of the valorization of mushroom species in northern Morocco, the current study aimed to investigate the chemical compositions and antioxidant properties of two wild edible mushrooms, Paralepista flaccida and Lepista nuda. Herein, the bioactive compounds were determined using spectrophotometer methods, and results showed that the value of total phenolic content (TPC) was found to be higher in P. flaccida (32.86 ± 0.52 mg) than in L. nuda (25.52 ± 0.56 mg of gallic acid equivalents (GAEs)/mg of dry methanolic extract (dme)). On the other hand, the value of total flavonoid content (TFC) was greater in L. nuda than in P. flaccida, with values of 19.02 ± 0.80 and 10.34 ± 0.60 mg of (+)-catechin equivalents (CEs)/g dme, respectively. Moreover, the ascorbic acid, tannin, and carotenoids content was moderate, with a non-significant difference between the two samples. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis allowed the identification and quantification of thirteen individual phenolic compounds in both P. flaccida and L. nuda, whereas p-Hydroxybenzoic acid was recognized as the major compound detected, with values of 138.50 ± 1.58 and 587.90 ± 4.89 µg/g of dry weight (dw), respectively. The gas chromatography-mass spectrometry (GC-MS) analysis of methanolic extracts of P. flaccida and L. nuda revealed the presence of sixty-one and sixty-six biomolecules, respectively. These biomolecules can mainly be divided into four main groups, namely sugars, amino acids, fatty acids, and organic acids. Moreover, glycerol (12.42%) and mannitol (10.39%) were observed to be the main chemical compositions of P. flaccida, while L. nuda was predominated by linolelaidic acid (21.13%) and leucine (9.05%). L. nuda showed a strong antioxidant property, evaluated by DPPH (half maximal effective concentration (EC50) 1.18-0.98 mg/mL); β-carotene bleaching (EC50 0.22-0.39 mg/mL); and reducing power methods (EC50 0.63-0.48 mg/mL), respectively. These findings suggested that both mushrooms are potential sources of various biomolecules, many of which possess important biological activities which are interesting for the foods and pharmaceuticals industry.

Efficient peroxymonosulfate activation by magnetic CoFe2O4 nanoparticle immobilized on biochar toward sulfamethoxazole degradation: Performance, mechanism and pathway

Utilizing biomass waste to create highly efficient biochar-based catalysts has drawn intensively interest since it adheres to the idea of waste recycling in environmental conservation. Herein, CoFe2O4 nanoparticles immobilized on biochar (BC) derived from rape straw were synthesized and applied in degrading sulfamethoxazole (SMX) by activating peroxymonosulfate (PMS). Experimental results indicated that the 30 wt% CoFe2O4/BC composite catalyst had the best catalytic activity with the SMX degradation efficiency of 93% within 20 min, which was probably the fact that BC as a carrier not only effectively inhibited the agglomeration of CoFe2O4 nanoparticles and increased the active sites, but also could simultaneously participate in the catalytic degradation reaction as an activator of PMS. In addition, cycle experiments illustrated that the as-prepared catalyst possessed the excellent stability, and the magnetic property measurements implied that they were convenient for separation and recovery. According to quenching experiments, electron paramagnetic resonance (EPR) and electrochemical studies, both radical and non-radical process participated into degrading SMX, where the generated SO4·-, ·OH and O2·- as the major radical active species while 1O2 and direct electron transfer were responsible for the non-radical route. Besides, using high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis, a potential SMX degradation pathway was suggested. The present CoFe2O4/BC composite would be a promising PMS activation catalyst for environmental remediation.

Sensitive detection of synthetic cannabinoids in human blood using magnetic polydopamine molecularly imprinted polymer nanocomposites.

Synthetic cannabinoids (SCs) are a series of artificial chemical substances with pharmacological properties similar to those of natural cannabinoids and their abuse poses a great risk to social security and human health. However, the highly sensitive detection of low concentrations of SCs in human serum remains a great challenge. In this work, we developed a highly sensitive, rapid and highly selective method for the detection of SCs in human serum. Magnetic molecularly imprinted polymer (MIP) nanocomposites were prepared through self-polymerization of dopamine and template molecules on the surfaces of magnetic beads. 9H-Carbazole-9-hexanol (9CH) was used as a template molecule because of its long chain structure shared with six synthetic cannabinoids and its ability to provide specific recognition sites. With these magnetic MIP nanoparticles, six SCs could be rapidly and effectively extracted from human blood. The concentrations of six SCs could be accurately determined by high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. The limits of detection were in the range of 0.1-0.3 ng mL-1. The proposed method is characterized by high sensitivity and selectivity, and has great potential for application in the analysis of practical samples.

Ligand fishing of monoamine oxidase B inhibitors from Platycodon grandiflorus (Jacq.) A.DC. roots by the enzyme functionalised magnetic nanoparticles.

As a famous traditional Chinese medicine, roots of Platycodon grandiflorus (Jacq.) A.DC. have shown multiple effects against neurodegenerative diseases. To investigate the components against Parkinson's disease (PD), the roots of P. grandiflora were selected as the research subject. Screening and identifying of monoamine oxidase B (MAO-B) inhibitors from the roots of P. grandiflorum via enzyme functionalised magnetic nanoparticles (MNPs)-based ligand fishing combined with high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. MAO-B functionalised MNPs have been synthesised for screening MAO-B inhibitors from the roots of P. grandiflorum. The ligands were identified by HPLC-MS and nuclear magnetic resonance (NMR) analysis, and their anti-PD activity was evaluated via MAO-B inhibition assay and cell viability assay in vitro. Two MAO-B inhibitors were fished out and identified by HPLC-MS as protocatechuic aldehyde (1) and coumarin (2), with the half maximal inhibitory concentrations of 28.54 ± 0.39 and 25.39 ± 0.29 μM, respectively. Among them, 1 could also significantly increase the viability of 6-hydroxydopamine-damaged PC12 cells. The results are helpful to elucidate the anti-PD activity of the plant, and the ligand fishing method has shown good potential in discovery of MAO-B inhibitors.

The HSP90 inhibitor 17-DMAG alleviates primary biliary cholangitis via cholangiocyte necroptosis prevention.

Cholangiocyte death accompanied by the progression of primary biliary cholangitis (PBC) has not yet been thoroughly investigated. Thus, we are aimed to explore the role of HSP90 and a potential treatment strategy in cholangiocyte necroptosis. First, we detected the expression of HSP90 and necroptotic markers in liver tissues from patients and mice with PBC by immunohistochemistry (IHC) and real-time polymerase chain reaction(PCR). Then, the HSP90 inhibitor, 17-dimethylaminoethylamino-17-demethoxygeldanamycin(17-DMAG), was administered by intraperitoneal injection to evaluate its therapeutic effect for PBC by IHC, real-timePCR, and western blotting. Human intrahepatic bile duct epithelial cells (HIBECs) were induced to necroptosis by toxic bile acid and lipopolysaccharide(LPS) treatment, and evaluated via Cell Counting Kit-8 and flow cytometry assays. Additionally, 17-DMAG, cycloheximide, and a proteasome inhibitor were used to evaluate the role of HSP90 in cholangiocyte necroptosis. We found that the expression of HSP90 was elevated in the cholangiocytes of patients and mice with PBC, along with higher expressions of receptor-interacting serine/threonine-protein kinase 1 (RIPK1), RIPK3, mixed lineage kinase domain-like protein (MLKL), andphosphorylated-MLKL(p-MLKL). Proinflammatory cytokines and antibody levels of the E2 subunit of pyruvate dehydrogenase complex decreased after treatment with 17-DMAG in PBC mice. Meanwhile, RIPK1, RIPK3, phosphorylated-RIPK3, MLKL, and p-MLKL protein expressions decreased with 17-DMAG treatment. In vitro, 17-DMAG and necrostatin-1 prevented glycochenodeoxycholic acid and LPS-induced necroptosis of HIBECs. Immunoprecipitation and high-performance liquid chromatography-mass spectrometry analysis showed that RIPK1 combined with HSP90. Additionally, the 17-DMAG treatment reduced the RIPK1 half-life. Overall, 17-DMAG might be a potential therapeutic agent for PBC via cholangiocyte necroptosis prevention by accelerating RIPK1 degradation.

Degradation of tiamulin by a packed bed dielectric barrier plasma combined with TiO2 catalyst

Recently, a plasma catalyst was employed to efficiently degrade antibiotic residues in the environment. In this study, the plasma generated in a packed bed dielectric barrier reactor combined with TiO2 catalyst is used to degrade the antibiotic tiamulin (TIA) loaded on the surface of simulated soil particles. The effects of applied voltage, composition of the working gas, gas flow rate and presence or absence of catalyst on the degradation effect were studied. It was found that plasma and catalyst can produce a synergistic effect under optimal conditions (applied voltage 25 kV, oxygen ratio 1%, gas flow rate 0.6 l min−1, treatment time 5 min). The degradation efficiency of the plasma combined with catalyst can reach 78.6%, which is 18.4% higher than that of plasma without catalyst. When the applied voltage is 30 kV, the gas flow rate is 1 l min−1, the oxygen ratio is 1% and the plasma combined with TiO2 catalyst treats the sample for 5 min the degradation efficiency of TIA reached 97%. It can be concluded that a higher applied voltage and longer processing times not only lead to more degradation but also result in a lower energy efficiency. Decreasing the oxygen ratio and gas flow rate could improve the degradation efficiency. The relative distribution and identity of the major TIA degradation product generated was determined by high-performance liquid chromatography–mass spectrometry analysis. The mechanism of TIA removal by plasma and TiO2 catalyst was analyzed, and the possible degradation path is discussed.

Determination of main alkylamides responsible for Zanthoxylum bungeanum pungency through quantitative analysis of multi-components by a single marker

The pungency of Chinese pepper (Zanthoxylum bungeanum) is mainly attributed to the alkylamides contained therein. However, the quantitation and application of these alkylamides are hindered by the lack of commercially available standards. Herein, five alkylamides mainly responsible for the pungency of Z. bungeanum were quantified in 31 batch samples of this plant by high-performance liquid chromatography-mass spectrometry and quantitative analysis of multi-components by a single marker (QAMS) to reveal significant differences in composition distribution according to the sample source. The two methods employed for this purpose, namely an external standard method and QAMS, were shown to be consistent, as the corresponding standardized mean difference was below 5.0%. Thus, the developed QAMS method was concluded to be a promising alternative for the comprehensive and effective quality control of Z. bungeanum from different sources.

Novel hyphenation of DGT in-situ passive sampling with YES assay to ascertain the potency of emerging endocrine disruptors in water systems in New Zealand

This study represents the first attempt to investigate selected estrogenic compounds that include 17α-ethynylestradiol (EE2), 17β-estradiol (E2) bisphenol A (BPA), and bisphenol AF (BPAF) along the drinkable water, from river-to-tap, and wastewater, from effluent-to-treated wastewater, treatment processes of the Hamilton City Council and the monitoring of the freshwater, from source-to-outfall, of the Waikato River in New Zealand. This was accomplished by the adoption of a novel combination of diffusive gradients in thin films (DGTs) in-situ passive sampling coupled with high-performance liquid chromatography/mass spectrometry analysis (HPLC/MS) and the Yeast Estrogen Screen (YES). Estradiol equivalency quantities, integrated in time, were evaluated theoretically (cEEQ) by DGT-HPLC/MS and experimentally (EEQ) by DGT-YES assay. cEEQ and EEQ highlighted that primary treatments are not suitable for estrogens and bisphenolic plastics removal both at drinkable and wastewater treatment plants in Hamilton where they worsen the water quality in terms of estrogenicity making these pollutants more available in the water phase. All downstream sites monitored along the Waikato River showed higher cEEQ and EEQ, moreover the Waikato River water quality showed a moderate worsening moving from Taupo (source) to Tuakau (outfall). The most polluted sites were downstream of Hamilton city and Huntly township wastewater treatment plants that serve the main conurbations in the area. cEEQ and EEQ generally showed good agreement at low concentrations but differed substantially at more polluted sites where cEEQ consistently underestimated estrogenic potency, possibly due to DGT accumulation of estrogenic compounds not quantified by HPLC/MS.