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A novel liquid-liquid-solid membrane microextraction (LLSMME) method which integrates hollow fiber liquid phase microextraction (HF-LPME) and solid phase microextraction (SPME) was developed for bio-sample preparation. The homogeneous zeolitic imidazolate framework 8 mixed matrix membrane (ZIF-8-MMM) was prepared by in situ self-assembly of ZIF-8 on the inner surface of hollow fiber membrane and employed as a flexible LLSMME device. Incorporating the advantages of both HF-LPME and SPME, the as-fabricated ZIF-8-MMM exhibited excellent performance on the extraction and preconcentration of small molecule drugs of different polarity from complex biological matrices. As a case study, ZIF-8-MMM-based LLSMME coupled with UPLC-MS/MS were developed and validated for determination of ibuprofen, simvastatin and ranitidine at trace levels in rat plasma. The method showed good linearity (r 2 > 0.99) and repeatability (RSD < 15%), low limits of detection (2–3 ng mL−1) and high relative recoveries (97.42–103.8%). The enrichment factors were between 87.3 and 112.6. Our study provided a promising strategy for developing more efficient, cost-effective and environmentally friendly technique for bio-sample pretreatment. Image 1 • A LLSMME method based on ZIF-8-MMM was firstly proposed for bio-sample extraction. • LLSMME method combines the advantages of SPME and HF-LPME. • In situ self-assembly of ZIF-8-MMM protect ZIF-8 from biological sample. • The ZIF-8-MMM can be prepared in batches and used 30 times. [ABSTRACT FROM AUTHOR]

• A pseudotargeted metabolomics-based RF model was built for tracking herbal species. • In-house database-driven identification of determinable chemicalome was performed. • The pseudotargeted method was built and validated to get semi-quantitative data. • The trained RF model showed high performance in predicting Astragalus species. The "one-to-multiple" phenomenon is prevalent in medicinal herbs. Accurate species identification is critical to ensure the safety and efficacy of herbal products but is extremely challenging due to their complex matrices and diverse compositions. This study aimed to identify the determinable chemicalome of herbs and develop a reasonable strategy to track their relevant species from herbal products. Take Astragali Radix-the typical "one to multiple" herb, as a case. An in-house database-driven identification of the potentially bioactive chemicalome (saponins and flavonoids) in AR was performed. Furthermore, a pseudotargeted metabolomics method was first developed and validated to obtain high-quality semi-quantitative data. Then based on the data matrix, the random forest algorithm was trained to predict Astragali Radix species from commercial products. The pseudotargeted metabolomics method was first developed and validated to obtain high-quality semi-quantitative data (including 56 saponins and 49 flavonoids) from 26 batches of AR. Then the random forest algorithm was well-trained by importing the valid data matrix and showed high performance in predicting Astragalus species from ten commercial products. This strategy could learn species-special combination features for accurate herbal species tracing and could be expected to promote the traceability of herbal materials in herbal products, contributing to manufacturing standardization. [Display omitted] [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a progressive neurodegenerative disease with neither definitive pathogenesis nor effective treatment method so far. Huang-Lian-Jie-Du-Tang (HLJDT) is a classic formula of traditional Chinese medicine (TCM) proven to have ameliorative effects on learning and memory deficits of dementia. Morris water maze (MWM) test and pathology analysis have demonstrated that HLJDT could ameliorate learning and memory deficits in AD mouse model, which may act via its anti-neuroinflammation properties. According to our previous studies, an UPLC-QTOF/MS-based metabolomics approach was performed to explore the potential mechanisms of HLJDT on preventing AD. As a result, a total of 23 potential metabolites (VIP >1, |Pcorr| >0.58, CUFjk excludes 0, P <  0.05) contributing to AD progress were identified. The metabolic pathway analysis with MetPA revealed that glycerophospholipid metabolism, sphingolipid metabolism, arachidonic acid metabolism, linoleic acid metabolism and tryptophan metabolism were disturbed in mouse model of AD. After HLJDT treatment, 14 metabolites were restored back to the control-like levels. [ABSTRACT FROM AUTHOR]

Abstract: A method based on the on-line turbulent-flow chromatography and fast high-performance liquid chromatography/mass spectrometry (TFC–LC/MS) was developed for sensitive and high throughput pharmacokinetic study of traditional Chinese medicines (TCMs). In this method, an on-line extraction column (Waters Oasis HLB) and a fast HPLC column with sub-2μm particle size (Agilent Zorbax StableBond-C18, 4.6mm×50mm, 1.8μm) in a column-switching set-up were utilized. HLB is a reversed-phase extraction column with hydrophilic–lipophilic balanced copolymer (2.1mm×20mm, 25μm particle size), which will exhibit some turbulent-flow properties at a high-flow rate. The method combines the speed and robustness of turbulent-flow extraction and the sensitivity and separation efficiency of fast HPLC–MS to analyze multiple and trace constituents of TCMs in plasma matrix. This method was successfully applied for pharmacokinetic study of verticine, verticinone and isoverticine, the chemical markers of Fritillaria thunbergii, after oral administration of total steroidal alkaloids extract of F. thunbergii to rats. Each plasma sample was analyzed within 7min. The method demonstrated good linearity (R >0.999) ranged from 0.505 to 96.0ng/mL with satisfactory accuracy and precision, and the lower limit of quantifications of verticine, verticinone and isoverticine were estimated to be 0.120, 0.595 and 0.505ng/mL, respectively. These results indicate that the proposed method is fast, sensitive, and feasible for pharmacokinetic study of TCMs. [Copyright &y& Elsevier]

[Display omitted] • Jujube polysaccharides stimulates EPO expression via HIF-α accumulation. • Jujube polysaccharides treatment improves kidney function and anemia in CKD rats. • Jujube polysaccharides significantly increases the release of SCFAs in CKD rats. • A derivatization-based LC-MS method is developed for SCFAs determination in feces. Jujube polysaccharides (JP) is one of the active food sourced glycans in dietary fruit of Ziziphus jujuba , which has been considered for the treatment of blood deficiency. In this study, a chronic kidney disease (CKD) rat model was used to evaluate the effect of JP and its mechanism on CKD-associated anemia. In CKD rats, JP treatment significantly ameliorated kidney function, kidney pathological injury and hematological parameters, including increasing red blood cells, hemoglobin, hematocrit and platelet count. Moreover, LC-MS/MS targeted metabolomics results showed that JP promoted short chain fatty acids (SCFAs) release in CKD rats. Besides, JP alternated the serum erythropoietin (EPO) level, kidney EPO mRNA and kidney EPO protein via HIF-α signaling. Collectively, these results provide evidence that the effect of JP on CKD-associated anemia may be involved in regulation of SCFAs release and erythropoietin production, supporting further development of JP as food supplements in treating CKD-associated anemia. [ABSTRACT FROM AUTHOR]

Neurotransmitter (NT) abnormalities in the enteric nervous system have been reported as crucial roles to regulate the intestinal inflammation and gut immune homeostasis. Capturing quantitative changes at the NT metabolome provides an opportunity to develop an understanding of neuroimmune-mediated inflammation. Given the wide diversity of chemical characterizations in the NTs, only partial coverage of the NT metabolome can be simultaneously quantified in a single-run analysis. Herein, we summarized the distribution of functional groups of compound entries in the NT metabolome. Based on this information, an orthogonal dansyl-labeling and label-free dual pretreatment approach was separately designed to target phenol and amine NTs and tertiary amine and choline NTs. By combining the dansyl-labeled and unlabeled NTs within a single vial, a comprehensive and practical approach was optimized for quantifying high coverage of NT metabolome in a single-run analysis on the reversed-phase C18 column. Method validation indicated good linearity with correlation coefficients (R2) > 0.99, intra- and interday accuracy with relative error < ±20%, and precision with relative standard deviations of ≤15%. With this method, we could simultaneously monitor the alterations of cholines, amines, amino acids, tryptophan and phenylalanine biological pathways in dextran sulphate sodium-induced colitis mice. The measured levels of NT metabolome ranged from 0.0007 to 3.540 μg/mg in intestinal contents and 0.013–154.54 μg/mL in serum samples. The NT metabolism was disrupted by colitis, characterized by the changed NT levels in serum and excessive amino acid NTs accumulation in the intestinal contents. We envisage that the orthogonal approach is of great significance for the comprehensive determination of targeted metabolomics. NTs have the potential to be biomarkers for clinical metabolomics. Image 1 • NT metabolome was summarized by the distribution of functional groups of compounds. • Ingenious design of orthogonal dual pretreatment in sample preparation for NT metabolome profiling. • Capturing changes of NT metabolome developed an understanding of neuroimmune-mediated inflammation. • Divide-and-conquer concept is of great significance in the targeted metabolomics. [ABSTRACT FROM AUTHOR]

Long chain unsaturated fatty acids (LCUFAs) are emerging as critical contributors to inflammation and its resolution. Sensitive and accurate measurement of LCUFAs in biological samples is thus of great value in disease diagnosis and prognosis. In this work, a fluorous-derivatization approach for UPLC-MS/MS quantification of LCUFAs was developed by employing a pair of fluorous reagents, namely 3-(perfluorooctyl)-propylamine (PFPA) and 2-(perfluorooctyl)-ethylamine (PFEA). With this method, the LCUFAs in biological samples were perfluoroalkylated with PFPA and specifically retained on a fluorous-phase LC column, which largely reduced matrix interferences-induced quantitation deviation. Moreover, PFEA-labeled LCUFAs standards were introduced as one-to-one internal standards to farthest ensure unbiased results. Application of the proposed method enabled a reliable determination of eight typical LCUFAs with high sensitivity (LLOQ ranged from 30 amol to 6.25 fmol) and low matrix interferences (almost less than 10%). Such a high sensitivity could facilitate the determination of small-volume and low-concentration bio-samples. Further metabolic characterization of these targeted LCUFAs was monitored in OVA-induce asthma mice, requiring only 5 μL serum sample. Our results showed that asthmatic attack led to significant disturbances not only in the concentrations but also in the ratio among these LCUFAs. In view of the favorable advantages in sensitivity and accuracy, the present fluorous-paired derivatization approach will be expected to serve as a new avenue for dissecting the physiological and clinical implications of LCUFAs, thereby shedding light on the management of diseases related to their disturbances. Image 1 • A pair of fluorous reagents was employed for profiling of LCUFAs. • Matrix effects were largely reduced by the specific fluorophilicity between fluorinated-LCUFAs. • PFEA-labeled LCUFAs standards were used as one-to-one ISs to farthest ensure unbiased results. • An extreme low detection limit was achieved at an atto-molar level. [ABSTRACT FROM AUTHOR]

Mass spectrometry-based approaches enable us to capture changes in the metabolome in biological systems with high sensitivity and resolution. But global MS-based profiling of the bile acids (BAs) submetabolome is still a challenging task. Particularly for unconjugated BAs, the collision-induced dissociation (CID) fragment ions showed low ion intensities which were insufficient for analysis. This study is aimed at the development of an anion attachment MS-based approach for pseudotargeted profiling of the BAs submetabolome. We demonstrated that anion attachment MS with the combination use of ammonia fluoride (NH 4 F) and formate could provide stable anionic adduct ([M + HCOO]−) with good MS responses for unconjugated BAs. A mechanistic study revealed that the underlying rationale is due to the NH 4 F-induced approximate matching of attractions between BAs and anion for the 24-carboxyl hydrogen. This 24-carboxyl hydrogen regioselectivity is useful to screen for potential unconjugated BAs from the biological matrix. The stability and regioselectivity of anion attachment allowed the establishment of SRM transitions for unconjugated BAs for the first time. To profile conjugated BAs that come from the conjugation of glycine or taurine at 24-carboxyl hydrogen, specific precursor/fragment ion transitions were used for the detection. Finally, SRM-based UPLC-MS/MS method was developed for the pseudotargeted profiling of the BAs submetabolome with good linearity (r2 > 0.995) and high sensitivity (0.20–1.37 ng mL−1 for LLOQ). With this method, a total of 83 BAs, covering 45 unconjugated BAs and 38 conjugated BAs, were successfully determined in different biosamples from experimental colitis mice. The BAs metabolism homeostasis was disrupted by colitis, characterized by the decreased BAs levels in serum and excessive BAs accumuation in the gall bladder and colon. Overall, the present anion attachment MS-based approach is sufficiently sensitive and robust to comprehensively measure various BAs. Image 1 • An anion attachment MS-based approach was developed for pseudotargeted profiling of BAs. • Structural calculation revealed the underlying rationale of NH 4 F-induced anion attachment. • The stability and regioselectivity of anion attachment led to the developed SRM transitions for unconjugated BAs. • Semi-quantitative BAs data was obtained in a DSS-induced murine colitis model. [ABSTRACT FROM AUTHOR]

With the rapid development of immunometabolism, 2-hydroxyglutarate (2-HG) is being promoted as a key immunometabolite to regulate the immune system. Based on the well-established crosstalk between 2-HG and other immunometabolites, here we firstly constructed a 2-HG metabolic panel by mapping the related metabolic pathways. Quantitative methods to globally monitor 2-HG metabolic panel are of great importance for immunometabolism study. However, the existence of enantiomer hampers the accurate measurement of these immunometabolites. This study addressed an original isotopically-paired chiral derivatization approach for UPLC-MS/MS quantification of 2-HG metabolic panel. To achieve better chromatographic separation, N-(p-toluenesulfonyl)-L-phenylalanyl chloride (TSPC) was utilized as an optical resolving reagent to form diastereomers. For accurate quantitation, an 18O 2 -labeled-TSPC reagent was designed and readily synthesized to produce one-to-one internal standards. The developed approach enabled an accurate quantification of 13 immunometabolites in 2-HG metabolic panel with good linearity (R2 > 0.99) and high sensitivity (0.5–120 fmol for LLOQ). With this method, we were able to simultaneously monitor the specific alterations of 2-HG metabolic panel in collagen-induced rheumatoid arthritis (CIA) rats. The measured levels of this panel ranged from 0.02 to 85.14 μg g−1 for synovium tissue and 0.012 to 87.75 μmol L−1 for serum samples. We envisage that the present isotopically-paired chiral derivatization approach will be practicable for different bio-samples to quantitatively profile the amino- and hydroxyl acids submetabolome, especially for the endogenous enantiomers. By virtue of the low cost of reagents and the simple procedure used in the assay, this method could be readily implemented. Image 1 • A 2-HG metabolic panel was constructed by mapping the related metabolic pathways. • A pair of 16 O 2 / 18 O 2 -TSPC was designed for the profiling of 2-HG metabolic panel. • Efficient separation and detection of endogenous enantiomers were performed. • 18O-labeled standards were used as one-to-one ISs for accurate quantification. • Key immunometabolites closely related to 2-HG metabolism were successfully quantified. [ABSTRACT FROM AUTHOR]