Discovery and analysis of microplastics in human bone marrow.

The health implications of human exposure to microplastics (MPs) have raised significant concerns. While evidence indicates MPs can accumulate in closed human organs like the heart, placenta, and blood, there is no available data on MP exposure specifically within the human bone marrow. To fill the research gap, this study detected the concentration of microplastics (MPs) in bone marrow samples by pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) and assessed the size range and morphological characteristics of MPs by Laser Direct Infrared Spectroscopy (LD-IR) and scanning electron microscopy (SEM). Our study shows that MPs were present in all 16 bone marrow samples, with an average concentration of 51.29 µg/g ranging from 15.37 µg/g to 92.05 µg/g. Five polymer types-polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polyadiohexylenediamine 66 (PA66), and polypropylene (PP), were identified. PE was the most frequent polymer detected in the bone marrow, with an average concentration of 30.02 µg/g ranging from 14.77 µg/g to 52.57 µg/g, with a detection rate of 93.75 %. PS had the highest detection rate at 100 % of bone marrow samples, while PVC and PA66 were found in 75 % of samples each. LD-IR analysis revealed the identification of 25 polymer types, with an average abundance of 19.72 particles/g. Of these, 89.82 % of the MPs were smaller than 100 µm. In summary, this study has, for the first time, demonstrated the presence of MPs are deeply embedded within human bone marrow, providing a basis for future investigations into their potential toxicological effects and underlying mechanisms affecting the hematopoietic system.

Sensitive quantification of mevalonate pathway intermediates and prediction of relative novel analogs by chemical derivatization-based LC-MS/MS.

The mevalonate (MVA) pathway plays a crucial role in the occurrence and progression of various diseases, such as osteoporosis, breast cancer, and lung cancer, etc. However, determining all the MVA pathway intermediates is still challenging due to their high polarity, low concentration, chelation effect with metal compartments, and poor mass spectrometric response. In this study, we established a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method coupled with N2, N2, N4, N4-tetramethyl-6-(4-(piperazin-1-ylsulfonyl) phenyl)-1,3,5-triazine-2,4-diamine (Tmt-PP) labeling for the simultaneous analysis of all MVA intermediates in biospecimens. Chemical derivatization significantly improved the chromatographic retention, peak shape, and detection sensitivity of the analytes. Moreover, we employed a method named mass spectrum calculation to achieve the absolute quantification of the isomers, i.e., isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). The established method was fully qualified and applied to explore the difference of these metabolites in cisplatin-resistant non-small cell lung cancer (NSCLC) cells. Additionally, several MVA intermediate analogs, including isopentenyl monophosphate or dimethylallyl monophosphate (IMP/DMAMP), geranyl monophosphate (GMP), 5-triphosphomevalonate (MTP), and isopentenyl triphosphate or dimethylallyl triphosphate (ITP/DMATP), were identified for the first time using a knowledge-driven prediction strategy. We further explored the tissue distribution of these novel metabolites. Overall, this work developed a sensitive quantification method for all MVA intermediates, which will enhance our understanding of the role of this pathway in various health and disease conditions. The novel metabolites we discovered warrant further investigations into their biosynthesis and biological functions.

Enhancing gas chromatography-mass spectrometry resolution and pure analyte discovery using intra-chromatogram elution profile matching.

Chemometric decomposition methods like multivariate curve resolution-alternating least squares (MCR-ALS) are often employed in gas chromatography-mass spectrometry (GC-MS) to improve analyte identification and quantitation. However, these methods can perform poorly for analytes with a low chromatographic resolution (Rs) and a high degree of spectral contamination from noise and background interferences. Thus, we propose a novel computational algorithm, termed mzCompare, to improve analyte identification and quantitation when coupled to MCR-ALS. The mzCompare method utilizes an underlying requirement that the retention time and peak shape between mass channels (m/z) of the same analyte should be similar. By discovering the selective m/z for a given analyte in a chromatogram, a pure elution profile can be generated and used as an equality constraint in MCR-ALS. The performance of the mzCompare methodology is demonstrated with both experimental and simulated chromatograms. Experimentally, unresolved analytes with a Rs as low as 0.05 could be confidently identified with mzCompare assisted MCR-ALS. Furthermore, application of the mzCompare algorithm to a complex aerospace fuel resulted in the discovery of 335 analytes, a 44 % increase compared to conventional peak detection methods. GC-MS simulations of target-interferent analyte pairs demonstrated that the performance of MCR-ALS deteriorated below a Rs of ∼0.25. However, mzCompare assisted MCR-ALS showed excellent identification and acceptable quantitative accuracy at a Rs of ∼0.02. These results show that the mzCompare algorithm can help analysts overcome modeling ambiguities resulting from the chemometric multiplex disadvantage.

Unraveling the mechanism of malancao in treating ulcerative colitis: A multi-omics approach.

BACKGROUND: Malancao (MLC) is a traditional Chinese medicine with a long history of utilization in treating ulcerative colitis (UC). Nevertheless, the precise molecular mechanisms underlying its efficacy remain elusive. This study leveraged ultra-high-performance liquid chromatography coupled with exactive mass spectrometry (UHPLC-QE-MS), network pharmacology, molecular docking (MD), and gene microarray analysis to discern the bioactive constituents and the potential mechanism of action of MLC in UC management. AIM: To determine the ingredients related to MLC for treatment of UC using multiple databases to obtain potential targets for fishing. METHODS: This research employs UHPLC-QE-MS for the identification of bioactive compounds present in MLC plant samples. Furthermore, the study integrates the identified MLC compound-related targets with publicly available databases to elucidate common drug disease targets. Additionally, the R programming language is utilized to predict the central targets and molecular pathways that MLC may impact in the treatment of UC. Finally, MD are conducted using AutoDock Vina software to assess the affinity of bioactive components to the main targets and confirm their therapeutic potential. RESULTS: Firstly, through a comprehensive analysis of UHPLC-QE-MS data and public database resources, we identified 146 drug-disease cross targets related to 11 bioactive components. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis highlighted that common disease drug targets are primarily involved in oxidative stress management, lipid metabolism, atherosclerosis, and other processes. They also affect AGE-RAGE and apoptosis signaling pathways. Secondly, by analyzing the differences in diseases, we identified key research targets. These core targets are related to 11 active substances, including active ingredients such as quercetin and luteolin. Finally, MD analysis revealed the stability of compound-protein binding, particularly between JUN-Luteolin, JUN-Quercetin, HSP90AA1-Wogonin, and HSP90AA1-Rhein. Therefore, this suggests that MLC may help alleviate intestinal inflammation in UC, restore abnormal lipid accumulation, and regulate the expression levels of core proteins in the intestine. CONCLUSION: The utilization of MLC has demonstrated notable therapeutic efficacy in the management of UC by means of the compound target interaction pathway. The amalgamation of botanical resources, metabolomics, natural products, MD, and gene chip technology presents a propitious methodology for investigating therapeutic targets of herbal medicines and discerning novel bioactive constituents.

Enhancing sodium percarbonate catalytic wet peroxide oxidation with artificial intelligence-optimized swirl flow: Ni single atom sites on carbon nanotubes for improved reactivity and silicon resistance.

H2O2 is widely used in the treatment of refractory organic pollutants.However, due to its explosive and corrosive chemical characteristics, H2O2 will bring great safety risks and troubles in transportation.So we chose sodium percarbonate(SPC) to be used in catalytic wet peroxide oxidation enhanced by swirl flow(SF-CWPO) and we designed carbon nanotubes with Ni single atom sites(Ni-NCNTs/AC) to activate SPC to treat an m-cresol wastewater containing Si.Meanwhile, artificial intelligence which used Artificial neural network (ANN) was used to optimize the conditions.Under the conditions of pH = 9.27, reaction time of 8.91 min, m-cresol concentration is 59.09 mg L-1, SPC dosage is 2.80 g L-1 and Na2SiO3·9H2O dosage is 77.27 mg L-1, the degradation rate of total organic carbon(TOC) and m-cresol reaches 94.37% and 100%, respectively.Finally, the applicability of Ni-NCNTs/AC-SPC-SF-CWPO technology was evaluated in a wastewater system of a sewage treatment enterprise and Fourier transform ion cyclotron resonance mass spectrum(FT-ICR MS) analysis and chemical oxygen demand(COD) analysis showed the great ability of Ni-NCNTs/AC-SPC-SF-CWPO technology to treat wastewater.It is believed that this paper is of great significance to the design and construction of the in-depth research and industrial application of SF-CWPO.

Column storage enables edge computation of biological big data on 5G networks.

With the continuous improvement of biological detection technology, the scale of biological data is also increasing, which overloads the central-computing server. The use of edge computing in 5G networks can provide higher processing performance for large biological data analysis, reduce bandwidth consumption and improve data security. Appropriate data compression and reading strategy becomes the key technology to implement edge computing. We introduce the column storage strategy into mass spectrum data so that part of the analysis scenario can be completed by edge computing. Data produced by mass spectrometry is a typical biological big data based. A blood sample analysed by mass spectrometry can produce a 10 gigabytes digital file. By introducing the column storage strategy and combining the related prior knowledge of mass spectrometry, the structure of the mass spectrum data is reorganized, and the result file is effectively compressed. Data can be processed immediately near the scientific instrument, reducing the bandwidth requirements and the pressure of the central server. Here, we present Aird-Slice, a mass spectrum data format using the column storage strategy. Aird-Slice reduces volume by 48% compared to vendor files and speeds up the critical computational step of ion chromatography extraction by an average of 116 times over the test dataset. Aird-Slice provides the ability to analyze biological data using an edge computing architecture on 5G networks.

Preparation of high-efficiency titanium ion immobilized magnetic graphite nitride nanocomposite for phosphopeptide enrichment.

BACKGROUND: Protein phosphorylation has been implicated in life processes including molecular interaction, protein structure transformation, and malignant disease. An in-depth study of protein phosphorylation may provide vital information for the discovery of early biomarkers. Mass spectrometry (MS)-based techniques have become an important method for phosphopeptide identification. Nevertheless, direct detection remains challenging because of the low ionization efficiency of phosphopeptides and serious interference from non-phosphopeptides. There is a great need for an efficient enrichment strategy to analyze protein phosphorylation prior to MS analysis. RESULTS: In this study, a novel nanocomposite was prepared by introducing titanium ions into two-dimensional magnetic graphite nitride. The nanocomposite was combined with immobilized metal ion affinity chromatography (IMAC) and anion-exchange chromatography mechanisms for phosphoproteome research. The nanocomposite had the advantages of a large specific surface (412.9 m2 g-1), positive electricity (175.44 mV), and excellent magnetic property (35.7 emu g-1). Moreover, it presented satisfactory selectivity (α-casein:ß-casein:bovine serum albumin = 1:1:5000), a low detection limit (0.02 fmol), great recyclability (10 cycles), and high recovery (92.8%). The nanocomposite demonstrated great practicability for phosphopeptides from non-fat milk, human serum, and saliva. Further, the nanocomposite was applied to enrich phosphopeptides from a more complicated specimen, A549 cell lysate. A total of 890 phosphopeptides mapping to 564 phosphoproteins were successfully detected with nano LC-MS. SIGNIFICANCE: We successfully designed and developed an efficient analysis platform for phosphopeptides, which includes protein digestion, phosphopeptide enrichment, and MS detection. The MS-based enrichment platform was further used to analyze phosphopeptides from complicated bio-samples. This work paves the way for the design and preparation of graphite nitride-based IMAC materials for phosphoproteome analysis.

Dracorhodin targeting CMPK2 attenuates inflammation: A novel approach to sepsis therapy.

BACKGROUND: Despite all modern advances in medicine, an effective drug for treating sepsis has yet to be found. The discovery of CMPK2 spurred hopes for the treatment of sepsis. However, CMPK2-untapped target inhibitors are still an enormous obstacle that has hindered the CMPK2-centric treatment of sepsis. METHODS: Here, we found that the CMPK2 gene is highly expressed in the whole blood of sepsis patients by RNA-Seq. First, recombinant CMPK2 was purified by a eukaryotic expression purification system, and the activity of recombinant CMPK2 was detected by the ADP-GLO assay. Second, we developed an affinity MS strategy combined with quantitative lysine reactivity profiling to discover CMPK2 ligands from the active ingredients of Chinese herbs. In addition, the dissociation constant Kd of the ligand and the target protein CMPK2 was further detected by microscale thermophoresis technology. Third, we used this strategy to identify a naturally sourced small molecule, dracorhodin (DP). Using mass spectrometry-based quantitative lysine reactivity profiling combined with a series of mutant tests, the results show that K265 acts as a bright hotspot of DP inhibition of CMPK2. Fourth, immune-histochemical staining, ELISAs, RT-qPCR, flow cytometry and immunoblotting were used to illustrate the potential function and related mechanism of DP in regulating sepsis injury. RESULTS: Our results suggest that DP exerts powerful anti-inflammatory effects by regulating the NLRP3 inflammasome via the lipopolysaccharide (LPS)-induced CMPK2 pathway. Strikingly, DP significantly attenuated LPS-induced sepsis in a mouse model, but its effect was weakened in mice with myeloid-specific Cmpk2 ablation. CONCLUSION: We provide a new framework that provides more valuable information for new therapeutic approaches to sepsis, including the establishment of screening strategies and the development of target drugs to provide a theoretical basis for ultimately improving clinical outcomes for sepsis patients. Collectively, these findings reveal that DP is a promising CMPK2 inhibitor for the treatment of sepsis.

Proteomic Analysis by 4D Label-free MS-PRM Provides Insight into the Role and Regulatory Mechanisms of IL-25 in NK Cells.

BACKGROUND: NK cells play an important role in immune response, immune surveillance, and metabolism regulation. Therefore, NK cells are involved in the occurrence and development of various diseases, such as infectious diseases, cancer, obesity, and diabetes. IL-25 is a special member of the IL-17 family with anti-inflammatory function. IL-25 can regulate inflammatory response and metabolism via various immune cells; however, the role and regulatory mechanism of IL-25 in NK cells are still unclear. METHOD: In this study, we investigate the role of IL-25 in NK-cell protein profile via 4D label-free mass spectrum and validate the differential proteins via PRM analysis. In addition, GO analysis, KEGG analysis, and other bioinformatic analysis methods are used to explore the enriched function and signal pathway of differentially expressed proteins. RESULT AND DISCUSSION: The GO and KEGG analyses suggest that IL-25 may affect the processes, such as metabolism, thermogenesis, and oxidative phosphorylation of NK cells. There are 7 down-regulated proteins (NCR1, GZMB, PRF1, KLRC1, NDUFA11, LAMTOR5, and IKBIP) and 1 up-regulated protein (PSMD7) in IL-25-treated NK cells versus the control group for PRM validation. Our results indicate that IL-25 may regulate metabolism and other biological processes via NK cells, which will be beneficial in revealing the role and regulatory mechanisms of IL-25 in NK cells in various diseases. CONCLUSION: Proteomics combined with bioinformatic analysis will help to mine more information hidden behind mass spectrometry data and lay the foundation for finding clinical biomarkers and mechanisms of diseases.

Erratum: Prevalence, genomic characterization and antimicrobial resistance of Campylobacter spp. isolates in pets in Shenzhen, China.

[This corrects the article DOI: 10.3389/fmicb.2023.1152719.].

Prevalence, genomic characterization and antimicrobial resistance of Campylobacter spp. isolates in pets in Shenzhen, China.

The prevalence of Campylobacter spp.in pets is a potential concern for human health. However, little is known about the pet-related Campylobacter spp. in China. A total of 325 fecal samples were collected from dogs, cats, and pet foxes. Campylobacter spp. were isolated by culture, and MALDI-TOF MS was used to identify 110 Campylobacter spp. isolates in total. C. upsaliensis (30.2%, 98/325), C. helveticus (2.5%, 8/325), and C. jejuni (1.2%, 4/325) were the three found species. In dogs and cats, the prevalence of Campylobacter spp. was 35.0% and 30.1%, respectively. A panel of 11 antimicrobials was used to evaluate the antimicrobial susceptibility by the agar dilution method. Among C. upsaliensis isolates, ciprofloxacin had the highest rate of resistance (94.9%), followed by nalidixic acid (77.6%) and streptomycin (60.2%). Multidrug resistance (MDR) was found in 55.1% (54/98) of the C. upsaliensis isolates. Moreover, 100 isolates, including 88 C. upsaliensis, 8 C. helveticus, and 4 C. jejuni, had their whole genomes sequenced. By blasting the sequence against the VFDB database, virulence factors were identified. In total, 100% of C. upsaliensis isolates carried the cadF, porA, pebA, cdtA, cdtB, and cdtC genes. The flaA gene was present in only 13.6% (12/88) of the isolates, while the flaB gene was absent. By analyzing the sequence against the CARD database, we found that 89.8% (79/88) of C. upsaliensis isolates had antibiotic target alteration in the gyrA gene conferring resistance to fluoroquinolone, 36.4% (32/88) had the aminoglycoside resistance gene, and 19.3% (17/88) had the tetracycline resistance gene. The phylogenetic analysis using the K-mer tree method obtained two major clades among the C. upsaliensis isolates. All eight isolates in subclade 1 possessed the gyrA gene mutation, the aminoglycoside and tetracycline resistance genes, and were phenotypically resistant to six classes of antimicrobials. It has been established that pets are a significant source of Campylobacter spp. strains and a reservoir for them. This study is the first to have documented the presence of Campylobacter spp. in pets in Shenzhen, China. In this study, C. upsaliensis of subclade 1 required additional attention due to its broad MDR phenotype and relatively high flaA gene prevalence.

Revealing the nature of hidden charm pentaquarks with machine learning.

We study the nature of the hidden charm pentaquarks, i.e., the Pc4312,Pc4440 and Pc(4457), with a neural network approach in pionless effective field theory. In this framework, the normal χ2 fitting approach cannot distinguish the quantum numbers of the Pc(4440) and Pc(4457). In contrast to that, the neural network-based approach can discriminate them, which still cannot be seen as a proof of the spin of the states since pion exchange is not considered in the approach. In addition, we also illustrate the role of each experimental data bin of the invariant J/ψp mass distribution on the underlying physics in both neural network and fitting methods. Their similarities and differences demonstrate that neural network methods can use data information more effectively and directly. This study provides more insights about how the neural network-based approach predicts the nature of exotic states from the mass spectrum.

Construction of a Mass Spectrum Library Containing Predicted Electron Ionization Mass Spectra Prepared Using a Machine Learning Model and the Development of an Efficient Search Method.

Electron ionization (EI) mass spectrum library searching is usually performed to identify a compound in gas chromatography/mass spectrometry. However, compounds whose EI mass spectra are registered in the library are still limited compared to the popular compound databases. This means that there are compounds that cannot be identified by conventional library searching but also may result in false positives. In this report, we report on the development of a machine learning model, which was trained using chemical formulae and EI mass spectra, that can predict the EI mass spectrum from the chemical structure. It allowed us to create a predicted EI mass spectrum database with predicted EI mass spectra for 100 million compounds in PubChem. We also propose a method for improving library searching time and accuracy that includes an extensive mass spectrum library.

Untargeted Lipidomics Method for the Discrimination of Five Crab Species by Ultra-High-Performance Liquid Chromatography High-Resolution Mass Spectrometry Combined with Chemometrics.

In this study, ultra-high-performance liquid chromatography high-resolution accurate mass-mass spectrometry (UHPLC-HRAM/MS) was applied to characterize the lipid profiles of five crab species. A total of 203 lipid molecular species in muscle tissue and 176 in edible viscera were quantified. The results indicate that Cancer pagurus contained high levels of lipids with a docosahexaenoic acid (DHA) and eicosapntemacnioc acid (EPA) structure in the muscle tissue and edible viscera. A partial least squares discriminant analysis (PLS-DA) showed that PE 16:0/22:6, PE P-18:0/20:5, PA 16:0/22:6 and PC 16:0/16:1 could be used as potential biomarkers to discriminate the five kinds of crabs. In addition, some lipids, such as PE 18:0/20:5, PC 16:0/16:1, PE P-18:0/22:6 and SM 12:1;2O/20:0, could be used as characteristic molecules to distinguish between Cancer magister and Cancer pagurus, which are similar in appearance. This study provides a new perspective on discriminating crab species from MS-based lipidomics.

Computational method for rapid screening of the metabolites of Pulsatilla chinensis in rats using UHPLC-Q-TOF/MS combined with mass spectrum-based orthogonal projection.

Screening metabolites in vivo can be challenging due to the complexity of traditional Chinese medicine (TCM) and the ambiguous intracorporal process. To resolve this problem, we established the mass spectrum-based orthogonal projection (MSOP) method to differentiate prototype compounds from metabolites in vivo and applied it to the study of metabolites of Pulsatilla chinensis (PC). Initially, the validity and feasibility of the MSOP method were verified by using the ultra- high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) data of reference solution. Then, the MSOP method was applied to screen the metabolites of PC. A total of 63 metabolites were identified in vivo (urine, feces, bile, and plasma samples) and in vitro (intestinal bacteria biological sample). The results indicated that the main metabolic pathways of pentacyclic triterpenoids were demethylation, oxidation, dehydration, sulfation, and glucuronidation reactions. This study contributes to developing an integrated strategy based on chemometrics to characterize and classify the metabolism feature of pentacyclic triterpenoids of PC. This will support the scientific and rational application of PC in the clinic. The MSOP method based on the orthogonality of MS signals was used to differentiate the prototype compounds from metabolites in vivo. The method provides scientific and reliable support for fully understanding the metabolic fate of TCM.

Risk control of host cell proteins in one therapeutic antibody produced by concentrated fed-batch (CFB) mode.

Multiple control strategies, including a downstream purification process with well-controlled parameters and a comprehensive release or characterization for intermediates or drug substances, were implemented to mitigate the potential risk of host cell proteins (HCPs) in one concentrated fed-batch (CFB) mode manufactured product. A host cell process specific enzyme-linked immunosorbent assay (ELISA) method was developed for the quantitation of HCPs. The method was fully validated and showed good performance including high antibody coverage. This was confirmed by 2D Gel-Western Blot analysis. Furthermore, a LC-MS/MS method with non-denaturing digestion and a long gradient chromatographic separation coupled with data dependent acquisition (DDA) on a Thermo/QE-HF-X mass spectrometer was developed as an orthogonal method to help identify the specific types of HCPs in this CFB product. Because of the high sensitivity, selectivity and adaptability of the new developed LC-MS/MS method, significantly more species of HCP contaminants were able to be identified. Even though high levels of HCPs were observed in the harvest bulk of this CFB product, the development of multiple processes and analytical control strategies may greatly mitigate potential risks and reduce HCPs contaminants to a very low level. No high-risk HCP was identified and the total amount of HCPs was very low in the CFB final product.

Biosynthesis and pharmacokinetics of Panax notoginseng enteric-coated soft capsules.

Background: To investigate the biosynthesis and pharmacokinetic course of enteric-coated soft capsules of Panax notoginseng saponins (PNS) in a beagle dog model. Methods: To satisfy the enteric properties of soft capsules, the PNS enteric soft gelatin capsules were prepared by formaldehyde impregnation and orthogonal experimental design. The fluidity of gelatin and the disintegration time were selected as evaluation indexes; the soft gelatin capsule content was self-emulsifying, and the Km value and the optimal prescription were determined by making three-phase diagrams; in vivo pharmacokinetics studies were performed on six beagle dogs with 3 dogs in each group. Beagle dogs were divided into two groups randomly. One group was given PNS self-emulsifying enteric capsule and the other was given market conventional capsules. Plasma samples were collected at different times. After 1 week, the crossover experiment was carried out. The plasma concentration was detected by HPLC-MS (high performance liquid chromatography-mass spectrometry). Then the pharmacokinetic parameters were calculated by non-compartment model analysis. Results: The range and variance analysis of the orthogonal test determined that the best prescription of total saponins of Panax notoginseng enteric soft capsule was:gelatin:glycerol:water =1:1:2, Soak the films in 1% formaldehyde for 1 hour. The contents of the soft capsule self-microemulsion are prescribed as: IPM (isopropyl myristate):Cremophor RH40:PEG400 (polyethylene glycol 400) =1:4.5:4.5 (with suitable PNS); the pharmacokinetic parameters of PNS self-emulsified enteric capsules and conventional capsules in the market are as follows: Rb1:Cmax is (18.05±0.26) and (15.50±0.51) ng/mL, Tmax is (2.00±0) and (3.00±0) h, AUC0→t is 98.49±1.16 and 34.46±2.02 (ng/mL)·h, relative bioavailability is 196.2%; Rg1: Cmax is 4.16±0.25 and 3.88±0.28 ng/mL, Tmax is 2.00±0 and 1.50±0 h, area under drug time curve (AUC)0→t is 11.80±2.93 and 10.45±2.29 (ng/mL)·h, relative bioavailability is 77.2%; R1:Cmax is 1.84±0.25 and 1.48±0.21 ng/mL, Tmax is 2.08±0.49 and 1.92±0.20 h, AUC0→t is 7.06±2.07 and 7.16±2.59 (ng/mL)·h, relative bioavailability is 117.7%. Conclusions: The experiment in vivo showed the higher relative bioavailability of PNS self-emulsifying enteric capsule compared with market conventional capsules. This will provide a potential application prospect for the clinical research and applications of PNS.

The clinical value of UPLC-MS/MS method for the determination of plasma and tissue isoniazid concentration in lymph node tuberculosis patients / 中国药师

Objective To investigate the correlation between isoniazid concentration in plasma and lymph node tissue of patients with lymph node tuberculosis,and to explore its clinical value.Methods The basic information of patients with lymph node tuberculosis in our hospital and venous blood samples and neck lymph node tissue samples at different time points were collected.UPLC-MS/MS method was established and isoniazid concentration in plasma and neck lymph node tissue samples was quantitatively detected,and the correlation between isoniazid concentration in plasma and lymph node tissue was analyzed.Results The linear range of isoniazid blood concentration and lymph node tissue concentration were 0.25-16 μg·mL-1(r=0.999 8)and 2-128 μg·g-1(r=0.998 8),respectively.The precision,accuracy,and matrix effect of each quality control sample met the requirements.Plasma isoniazid concentration and lymph node tissue isoniazid concentration were significantly correlated at 10 min(rs=0.501 1,P=0.001),30 min(rs=0.402 8,P=0.005)and 60 min(rs=0.614 6,P=0.001)after intravenous infusion of isoniazid.The ratio of lymph node tissue isoniazid concentration to plasma isoniazid concentration was 1.46(0.62,3.55)mL·g-1 at 10 min.At 30 min,the ratio was 5.25(4.61,11.61)mL·g-1.At 60 min,the ratio was 6.62(4.42,10.78)mL·g-1.Conclusion The established UPLC-MS/MS method has good specificity,high sensitivity,accurac and precision.Monitoring plasma isoniazid concentration provides a reference for the rational use of isoniazid in patients with lymphatic tuberculosis.

2,5-Diketopiperazines: A Review of Source, Synthesis, Bioactivity, Structure, and MS Fragmentation.

BACKGROUND: 2,5-Diketopiperazines (DKPs), also called cyclic dipeptides, are the simplest peptide derivatives in nature that are formed by the condensation of two amino acids. They are an important category of bioactive substances with various structures. OBJECTIVE: This review focuses on the natural sources, synthetic processes, biological properties and MS fragmentation regularity of simple DKPs, in order to provide a reference for exploring future scientific and therapeutic potentials of these compounds. METHODS: Pertinent information was collected and organized from several electronic scientific databases (e.g., Web of Science, China Knowledge Resource Integrated, ScienceDirect, PubMed, Wanfang Data and Google Scholar), PhD and MS dissertations. There are 107 articles published from the early 20th century to 2021 that were reviewed in this work. RESULTS: DKPs have been obtained from a broad range of natural resources, including fungi, bacteria, plants, and animals, and have been synthesized by chemical and biological methods. DKPs have various pharmacological activities, including anticancer, antibacterial, antithrombotic, neuron protective, analgesic, and other activities. Mass spectrometry is the most common method for the structural analysis of DKPs. DKPs can be quickly screened and identified by MS according to the mass spectrum fragmentation pattern. CONCLUSION: As a category of relatively unexplored compounds, DKPs have been demonstrated to have various bioactivities, especially with antitumor and antibacterial activities. However, the existing research on DKPs is still in the early stage, and their application in drug development needs to be further studied.

Novel automated identification and quantification database using liquid chromatography quadrupole time-of-flight mass spectrometry for quick, comprehensive, cheap and extendable organic micro-pollutant analysis in environmental systems.

In order to protect human health and the environment, highly efficient, low-cost, labor-saving, and green analysis of toxic chemicals are urgently required. To achieve this objective, we have developed a novel database-based automated identification and quantification system (AIQS) using LC-QTOF-MS. Since the AIQS uses retention times (RTs), exact MS and MS-MS spectra, and calibration curves of 484 chemicals registered in the database instead of the use of standards, the targets can be determined with low-cost in a short time. The AIQS uses Sequential Window Acquisition of All Theoretical Fragment-ion Spectra as an acquisition method by which we can obtain accurate MS and MS-MS spectra of all detectable substances in a sample with minimal interference from co-eluted peaks. Identification is certainly done using RTs, mass error, ion ratios (a precursor to two product ions), and accurate MS and MS-MS spectra. Consequently, the chance of misidentification is very low even in dirty samples. To examine the accuracy of the AIQS, two collaborative tests were conducted. The first test used 208 pesticide standards at two concentrations (10 and 100 ng mL-1) using 7 instruments, and showed that average trueness was 106 and 95.2%, respectively, with relative standard deviations of 90% of the test compounds below 30%. The second collaborative study involved 5 laboratories carrying out recovery tests on 200 pesticides using 10 river waters. The average recovery was 71.6%; this was 15% lower than that using purified water probably due to the matrix effects. The average relative standard deviation was 30% worse than that of measurement of the standards. Both the recovery and reproducibility, however, satisfied the criteria of Analytical Method Validity Guidelines, Ministry of Health, Labour and Welfare, Japan. Instrument detection limits of 96% of the registered compounds are below 10 pg. The AIQS allows for easy addition of new substances and retrospective analysis after their addition. The results applied to actual samples showed that the AIQS has sufficient identification and quantification performance as a target screening method for a large number of substances in environmental samples.