A Rapid and Accurate UHPLC Method for Determination of Monosaccharides in Polysaccharides of Different Sources of Radix Astragali and Its Immune Activity Analysis.

With the escalating demand for Astragalus polysaccharides products developed from Radix Astragali (RA), the necessity for quality control of polysaccharides in RA has become increasingly urgent. In this study, a specific method for the simultaneous determination of seven monosaccharides in polysaccharides extracted from Radix Astragali (RA) has been developed and validated using ultra-performance liquid chromatography equipped with an ultraviolet detector (UHPLC-UV) for the first time. The 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatizations were separated on a C18 column (Waters ACQUITYTM, Milfor, MA, USA, 1.8 µm, 2.1 × 100 mm) using gradient elution with a binary system of 5 mm ammonium formate (0.1% formic acid)-acetonitrile for 24 min. Additionally, seven monosaccharides showed good linear relationships (R2, 0.9971-0.9995), adequate precision (RSD < 4.21%), and high recoveries (RSD < 4.70%). The established method was used to analyze 109 batches of RA. Results showed that the Astragalus polysaccharides (APSs) mainly consist of mannose (Man), rhamnose (Rha), glucose (Glu), galactose (Gal), arabinose (Ara), xylose (Xyl); and fucose (Fuc); however, their composition was different among RA samples from different growth patterns, species, growth years, and origins, and the growth mode of RA and the age of wild-simulated RA can be accurately distinguished by principal component analysis (PCA). In addition, the immunological activity of APSs were also evaluated jointly by measurement of the NO release with RAW264.7, with the results showing that APSs have a promoting effect on the release of NO and exhibit a significant correlation with Man, Glu, Xyl, and Fuc contents. Accordingly, the new established monosaccharides analytical method and APS-immune activity determination in this study can provide a reference for quality evaluation and the establishment of quality standards for RA.

Classification and Authentication of Lonicerae Japonicae Flos and Lonicerae Flos by Using 1H-NMR Spectroscopy and Chemical Pattern Recognition Analysis.

Lonicerae japonicae flos and Lonicerae flos are increasingly widely used in food and traditional medicine products around the world. Due to their high demand and similar appearance, they are often used in a confused or adulterated way; therefore, a rapid and comprehensive analytical method is highly required. In this case, the comparative analysis of a total of 100 samples with different species, growth modes, and processing methods was carried out by nuclear magnetic resonance (1H-NMR) spectroscopy and chemical pattern recognition analysis. The obtained 1H-NMR spectrums were employed by principal component analysis (PCA), partial least-squares discriminant analysis (PLS-DA), orthogonal partial least-squares discriminant analysis (OPLS-DA), and linear discriminant analysis (LDA). Specifically, after the dimensionality reduction of data, linear discriminant analysis (LDA) exhibited good classification abilities for the species, growth modes, and processing methods. It is worth noting that the sample prediction accuracy from the testing set and the cross-validation predictions of the LDA models were higher than 95.65% and 98.1%, respectively. In addition, the results showed that macranthoidin A, macranthoidin B, and dipsacoside B could be considered as the main differential components of Lonicerae japonicae flos and Lonicerae Flos, while secoxyloganin, secologanoside, and sweroside could be responsible for distinguishing cultivated and wild Lonicerae japonicae Flos. Accordingly, 1H-NMR spectroscopy combined with chemical pattern recognition gives a comprehensive overview and provides new insight into the quality control and evaluation of Lonicerae japonicae flos.

Integrating Anti-Influenza Virus Activity and Chemical Pattern Recognition to Explore the Quality Evaluation Method of Lonicerae Japonicae Flos.

Lonicerae japonicae flos (LJF, Lonicera japonica Thunb.) is adopted as a core herb for preventing and treating influenza. However, the anti-influenza virus components of LJF and the impact of quality-affecting factors on the anti-influenza activity of LJF have not been systematically investigated. In this study, a strategy integrating anti-influenza virus activity, ultrahigh-performance liquid chromatography fingerprint and chemical pattern recognition was proposed for the efficacy and quality evaluation of LJF. As a result, six bioactive compounds were screened out and identified as neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, 4,5-Di-O-caffeoylquinic acid, sweroside and secoxyloganin. Based on the bioactive compounds, chemical pattern recognition models of LJF were established by a linear discriminant analysis (LDA). The results of the LDA models and anti-influenza virus activity demonstrated that cultivation pattern significantly affected the anti-influenza effect of LJF and that the neuraminidase inhibition rate of wild LJF was significantly higher than that of cultivated LJF. Moreover, the quality of LJF samples with different processing methods and geographical origins showed no obvious difference. Overall, the proposed strategy in the current study revealed the anti-influenza virus components of LJF and provided a feasible method for thequality evaluation of LJF, which has great importance for assuring the clinical effect against influenza of LJF.

Discrimination of Lonicerae Japonicae Flos according to species, growth mode, processing method, and geographical origin with ultra-high performance liquid chromatography analysis and chemical pattern recognition.

Lonicerae japonicae flos (LJF, Lonicera japonica Thunb.) is often confused and/or adulterated with Lonicerae flos (LF, Lonicera macrantha (D.Don) Spreng.). Ecological conditions and processing methods strongly influenced the safety and efficacy of LJF. For the strict quality control of LJF, a rapid and feasible strategy for identification and classification of LJF by species, growth mode, processing method and geographical origin, based on chromatographic profiles and pattern recognition analysis, in 119 batches of Lonicera samples was systematically established. Firstly, comprehensive analysis of the chemical compositions of LJF was achieved using ultra-high performance liquid chromatography (UHPLC). Next, unsupervised principal component analysis showed that the influence of species, growth mode, processing method and geographical origin displayed a decreasing trend. Subsequently, classification models for authentication of LJF samples were established by linear discriminant analysis (LDA) with good classification abilities. Finally, sweroside and secoxyloganin could be considered as markers associated of cultivated and wild LJF, respectively, while 3-O-caffeoylquinic acid and 3,5-Di-O-caffeoylquinic acid could be regarded as markers for LF. Consequently, the findings suggest that UHPLC profiles combined with pattern recognition analysis is precise and feasible strategy for the discrimination and quality control of LJF.

Chemical characteristics of Rhodiola Crenulata and its mechanism in acute mountain sickness using UHPLC-Q-TOF-MS/MS combined with network pharmacology analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodiola crenulata (Hook.f. & Thomson) H.Ohba has a long history of clinical application for the prevention and treatment of acute mountain sickness (AMS) in traditional Chinese medicine. However, gaps in knowledge still exist in understanding the underlying mechanisms of Rhodiola crenulata against AMS. AIMS: To address this problem, a comprehensive method was established by combining UHPLC-Q-TOF-MS/MS analysis and network pharmacology. MATERIALS AND METHODS: The ingredients of Rhodiola crenulata were comprehensively analyzed using UHPLC-Q-TOF-MS/MS method. On this basis, a network pharmacology method incorporated target prediction, protein-protein interaction network, gene enrichment analysis and components-targets-pathways network was performed. Finally, the possible mechanisms were verified through molecular docking, in vitro and in vivo experiments. RESULTS: A total of 106 constituents of Rhodiola crenulata were charactered via UHPLC-Q-TOF-MS/MS. The 98 potentially active compounds out of 106 were screened and corresponded to 53 anti-AMS targets. Gene enrichment analysis revealed that hypoxia and inflammation related genes may be the central factors for Rhodiola crenulata to modulate AMS. Molecular docking revealed that TNF, VEGFA and HIF-1α had high affinities to Rhodiola crenulata compounds. Subsequently, Rhodiola crenulata extract was indicated to inhibit the protein expression level of TNF in hypoxia induced H9c2 cells. Lastly, Rhodiola crenulata extract was further verified to ameliorate heart injury and decreased the heart levels of TNF, VEGFA and HIF-1α in acute hypoxia-induced rats. CONCLUSIONS: This study used UHPLC-Q-TOF-MS/MS analysis and a network pharmacology to provide an important reference for revealing the potential mechanism of Rhodiola crenulata in the prevention and treatment of AMS.

The Study of Steaming Durations and Temperatures on the Chemical Characterization, Neuroprotective, and Antioxidant Activities of Panax notoginseng.

Panax notoginseng (PN) is one of the most valuable traditional Chinese medicines and has extensive pharmacological effects. Recent studies demonstrated that PN exhibited pharmacological effect related to Alzheimer's disease (AD). However, whether steaming process can boost its anti-AD activity is still unexplored. To fill this gap, effects of steaming durations and temperatures on the chemical characterization, neuroprotective and antioxidant activities of PN were systematically investigated in this study. HPLC fingerprint coupled with quantitative analysis demonstrated striking conversion of original saponins to less polar ones with the increase in the steaming time and temperature. In the viewpoint of anti-AD activity on neuroprotective and antioxidant effects, several steamed PN samples (110°C-6/8/10 h, 120°C -4/6 h samples) displayed a significant increase both in cell viability and oxygen radical absorption capacity (ORAC) values compared with the no steamed one (P < 0.01 or P < 0.005). Steaming temperature had the greater impact on the change of chemical composition and anti-AD activity of PN. Moreover, the spectrum-effect relationship analysis revealed that the transformed saponins were partially responsible for the increased neuroprotective and antioxidant effects of steamed PN. Therefore, steamed PN could be used as a potential crude drug for prevention and treatment of AD.

Application of UHPLC Fingerprints Combined with Chemical Pattern Recognition Analysis in the Differentiation of Six Rhodiola Species.

Rhodiola, especially Rhodiola crenulate and Rhodiola rosea, is an increasingly widely used traditional medicine or dietary supplement in Asian and western countries. Because of the phytochemical diversity and difference of therapeutic efficacy among Rhodiola species, it is crucial to accurately identify them. In this study, a simple and efficient method of the classification of Rhodiola crenulate, Rhodiola rosea, and their confusable species (Rhodiola serrata, Rhodiola yunnanensis, Rhodiola kirilowii and Rhodiola fastigiate) was established by UHPLC fingerprints combined with chemical pattern recognition analysis. The results showed that similarity analysis and principal component analysis (PCA) could not achieve accurate classification among the six Rhodiola species. Linear discriminant analysis (LDA) combined with stepwise feature selection exhibited effective discrimination. Seven characteristic peaks that are responsible for accurate classification were selected, and their distinguishing ability was successfully verified by partial least-squares discriminant analysis (PLS-DA) and orthogonal partial least-squares discriminant analysis (OPLS-DA), respectively. Finally, the components of these seven characteristic peaks were identified as 1-(2-Hydroxy-2-methylbutanoate) ß-D-glucopyranose, 4-O-glucosyl-p-coumaric acid, salidroside, epigallocatechin, 1,2,3,4,6-pentagalloyglucose, epigallocatechin gallate, and (+)-isolarisiresinol-4'-O-ß-D-glucopyranoside or (+)-isolarisiresinol-4-O-ß-D-glucopyranoside, respectively. The results obtained in our study provided useful information for authenticity identification and classification of Rhodiola species.

Developing a novel and simple biosensor for Cystatin C as a fascinating marker of glomerular filtration rate with DNase I-aided recycling amplification strategy.

Cystatin C (Cys C) has been proposed as a fascinating glomerular filtration rate (GFR) marker for early detection of acute kidney injury and chronic kidney disease. However, most of traditional methods for Cys C detection are immunoassays, which was tedious to perform and unfriendly for economics. In this work, a novel and simple biosensor for the sensitive measurement of Cys C via DNase I-aided recycling amplification strategy was successfully constructed based on the graphene oxide (GO) and fluorophore-labelled aptamer, which can be used to the early prediction of kidney injury. The fluorescence of fluorophore-labelled aptamer was quenched by GO based on the Fluorescence Resonance Energy Transfer (FRET) and recovered with the existence of Cys C. In addition, the DNase I enzyme would digest the fluorophore-labelled aptamer and dissociate the Cys C to launch the next reaction, resulting in an increase of signal amplification. Hence, the limit of detection is found to be 0.16 ng mL-1, which is almost 3 times lower than that without DNase I. Consequently, the developed biosensor offers a novel approach towards simple and rapid detection of Cys C based on the integration of GO and aptamer. Conceivably, this strategy holds a wide scope in the application of numerous other analytes if corresponding aptamers are available.

Chemical Pattern Recognition for Quality Analysis of Lonicerae Japonicae Flos and Lonicerae Flos Based on Ultra-High Performance Liquid Chromatography and Anti-SARS-CoV2 Main Protease Activity.

Lonicerae japonicae flos (L. japonicae flos, Lonicera japonica Thunb.) is one of the most commonly prescribed botanical drugs in the treatment or prevention of corona virus disease 2019. However, L. japonicae flos is often confused or adulterated with Lonicerae flos (L. flos, Lonicera macrantha (D.Don) Spreng., Shanyinhua in Chinese). The anti-SARS-CoV2 activity and related differentiation method of L. japonicae flos and L. flos have not been documented. In this study, we established a chemical pattern recognition model for quality analysis of L. japonicae flos and L. flos based on ultra-high performance liquid chromatography (UHPLC) and anti-SARS-CoV2 activity. Firstly, chemical data of 59 batches of L. japonicae flos and L. flos were obtained by UHPLC, and partial least squares-discriminant analysis was applied to extract the components that lead to classification. Next, anti-SARS-CoV2 activity was measured and bioactive components were acquired by spectrum-effect relationship analysis. Finally, characteristic components were explored by overlapping feature extracted components and bioactive components. Accordingly, eleven characteristic components were successfully selected, identified, quantified and could be recommended as quality control marker. In addition, chemical pattern recognition model based on these eleven components was established to effectively discriminate L. japonicae flos and L. flos. In sum, the demonstrated strategy provided effective and highly feasible tool for quality assessment of natural products, and offer reference for the quality standard setting.

In Vitro and In Vivo Anti-AChE and Antioxidative Effects of Schisandra chinensis Extract: A Potential Candidate for Alzheimer's Disease.

Acetylcholinesterase (AChE) inhibition and antioxidants are two common strategies for the treatment in the early stage of Alzheimer's Disease (AD). In this study, extracts from nine traditional Chinese medical (TCM) herbs were tested for anti-AChE activity by Ellman's microplate assay and cytotoxicity by CCK-8. Based on its excellent AChE inhibition effect and its lowest cytotoxicity, Schisandra chinensis (SC) extract was selected to do the mechanism research. SC extract protected pheochromocytoma (PC12) cells against H2O2-induced toxicity by improving the cell survival rate in a dose-dependent manner. And it also showed significant free radical (DPPH) scavenging activities, ferric reducing antioxidant power (FRAP), and 2,2'-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging. To confirm these results, the scopolamine-induced mice models were utilized in this study. Compared with the positive drug (piracetam), SC could also exhibit similar effects to alleviate the mice's cognitive deficits. Moreover, in the mice brain samples, the AChE activity and malondialdehyde (MDA) levels of SC-treatment group both showed a reverse as compared to model group. Taken together, these results all suggested that SC extract may be a potential therapeutic candidate for AD.

[A liquid chromatography-mass spectrometry-based metabolomic study on the changes of intracellular lipid metabolism regulated by Pokemon].

Pokemon, a transcriptional repressor, inhibits the transcription of tumor suppressor genes and promotes tumor formation by affecting chromatin recombination or binding directly to the tumor suppressor genes. In this study, the mechanism behind the Pokemon regulation of liver cancer cell metabolism was evaluated using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. Pokemon-overexpressing HL7702 cells were obtained by lipofection. The cells were collected at different time points after transfection and their intracellular metabolites were analyzed using an LC-MS-based metabolomic method. Based on the results of a multivariate statistical analysis, candidate metabolites with significant differences were selected, and 36 of them were confirmed by database and MS/MS analysis. These metabolites were primarily involved in lipid synthesis by KEGG database searches. Further analysis indicated that both the acetyl-coenzyme carboxylase and the fatty acid synthase were activated in the lipid synthesis pathway. The results show that Pokemon can affect cell metabolism by activating the lipid synthesis pathways in cells.

Evaluation of bisphenol A exposure induced oxidative RNA damage by liquid chromatography-mass spectrometry.

Highlighted evidence suggests the possible implication of bisphenol A (BPA) exposure on a variety of biological functions, such as DNA damage. Similar to DNA, exposed to BPA may also have potential risks to RNA damage due to its induction of reactive oxygen species. However, there are no related research reports about such health risks of BPA. Therefore, this work tried to investigate the BPA exposure induced oxidative RNA damage by detecting urinary nucleosides, the end-products of RNA metabolism. An ultra-high performance liquid chromatography-Orbitrap mass spectrometry method was applied to selectively and sensitively determine urinary nucleosides. As a result, 66 nucleosides were identified and the effects of BPA exposure on these nucleosides in rat urine samples were evaluated. The nucleosides showed different changing tendency along with different exposure dose of BPA. The strongest effect was observed in high does-exposure rats, indicating dose-response relationship between BPA-treatment and urinary nucleosides. Significant change of some nucleosides, including 8-oxoguanosine, was observed in the high-dose exposure group, suggesting obvious RNA damage to rats. To the best of our knowledge, it is the first study about the RNA damage induced by BPA exposure. The results provided a new perspective on the toxic effects of BPA exposure.

HPLC-MS/MS determination of flavonoids in Gleditsiae Spina for its quality assessment.

Gleditsiae Spina, the thorn of Gleditsia sinensis Lam., has been used as an anti-inflammatory, anti-tumor, and anti-bacterial traditional medicine for hundreds of years in China. This study used high-performance liquid chromatography and tandem mass spectrometry combined with chemometric methods to allow the fast and accurate identification and quantification of the flavonoids compounds in Gleditsiae Spina, and created reliable criteria for accurate identification of Gleditsiae Spina and its adulterants. This research provides good evidence for the classification and quality evaluation of Gleditsiae Spina. Firstly, eight flavonoids compounds were detected and identified on the basis of their mass spectra, fragment characteristics, and comparison with published data. Then the mass spectroscopic fragmentation pathways of these compounds were determined and, in addition rutin, isoquercitrin, and quercitrin were detected in Gleditsiae Spina for the first time. The quantification was performed on a triple quadrupole tandem mass spectrometer in multi-reaction monitoring mode, and the baseline separation of the eight bioactive flavonoids components was achieved within 13 min. Furthermore, the proposed method was successfully applied for simultaneous quantitative determination of the eight Gleditsiae Spina compounds and adulterants obtained from different sources in China. Then, we built a classification model which showed a high level of accuracy predicting 100% of the samples, correctly.

Urinary profiling of cis-diol-containing metabolites in rats with bisphenol A exposure by liquid chromatography-mass spectrometry and isotope labeling.

Exposure to bisphenol A (BPA), an environmental contaminant, has been linked to metabolic disorders. However, there are no reports describing the effects of BPA on the profiling of cis-diol metabolites. It is challenge to detect these metabolites in biological samples because of their low abundance, high polarity and serious matrix interference. In this study, a chemical isotope-labeling method was applied to solve these problems. Acetone and deuterated acetone (acetone-d6) were used as chemical tags to label the rat urine samples, respectively. The light and heavy labeling products were recognized using the ShiftedIonsFinder software. The selected cis-diol metabolite signals were used to build a data set. The data set was applied to evaluate the changes in the urinary profiling of cis-diol-containing metabolites in rats with BPA exposure. The results showed that chromatographic separation and mass spectrometry detection of cis-diol metabolites were improved after acetone labeling. Using this method, the cis-diol metabolites were recognized easily from the urine samples. By comparing different dose administration on rats, the influence of BPA exposure on cis-diol metabolites was investigated. The analytes showing noticeable differences were identified. It was found that high-dose BPA exposure had strong effects on the cis-diol compound metabolism. The influences were mostly related to the metabolism of galactose and nucleoside and its analogues. The disturbance of the galactose metabolism by BPA is reported for the first time, to the best of our knowledge. This may have some implications for exploring the toxic effects of BPA exposure.

A novel method of liquid chromatography-tandem mass spectrometry combined with chemical derivatization for the determination of ribonucleosides in urine.

Ribonucleosides are the end products of RNA metabolism. These metabolites, especially the modified ribonucleosides, have been extensively evaluated as cancer-related biomarkers. However, the determination of urinary ribonucleosides is still a challenge due to their low abundance, high polarity and serious matrix interferences in urine samples. In this study, a derivatization method based on a chemical reaction between ribonucleosides and acetone to form acetonides was developed for the determination of urinary ribonucleosides. The derivative products, acetonides, were detected by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The methodological evaluation was performed by quantifying four nucleosides for linear range, average recovery, precision, accuracy and stability. The validated procedures were applied to screen modified ribonucleosides in urine samples. Improvement of separation and enhancement of sensitivity were obtained in the analysis. To identify ribonucleosides, inexpensive isotope labeling acetone (acetone-d6) and label-free acetone were applied to form ordinary and deuterated acetonides, respectively. The two groups of samples were separated with orthogonal partial least squares (OPLS). The ordinary and deuterated pairs of acetonides were symmetrically distributed in the S-plot for easy and visual signal identification. After structural confirmation, a total of 56 ribonucleosides were detected, 52 of which were modified ribonucleosides. The application of derivatization, deuterium-labeling and multivariate statistical analysis offers a new option for selective detection of ribonucleosides in biological samples.

[Fingerprint of Solanum nigrum L. from different habitats using high performance liquid chromatography with evaporative light-scattering detection].

Solanum nigrum L. contains a variety of active ingredients. It has been applied broadly in clinical practice. However, the compositions of Solanum nigrum L. from different cultivated areas are quite different. Therefore, it is necessary to set up a standard fingerprint. In this work, a series of Solanum nigrum L. samples were collected from different habitats. A high performance liquid chromatography with evaporative light-scattering detection (HPLC-ELSD) method was developed to study the differences in quality of these samples. The method was optimized by comparing different columns, gradient or isocratic elution and temperatures of evaporating tube. A Phenomenex C18 column was finally selected for separation with gradient elution. The mobile phases were acetonitrile-20% (v/v) methanol aqueous solution containing 0. 03% (v/v) triethylamine. The temperature of evaporating tube was set at 40 °C. The validation was performed and the results showed that the method had good precision, repeatability and stability. The validated method was applied to detect Solanum nigrum L. from different habitats. The similarities of the acquired chromatograms were analyzed by using the similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine (TCM). The chromatograms with a similarity between 0. 9 and 1. 0 were normalized and fitted to form a standard fingerprint of Solanum nigrum L. Thirteen common peaks were found and eleven peaks were identified with authentic standards. The results showed that remarkable differences were found among Solanum nigrum L. from different habitats. These herbs could be distinguished based on the compositions detected by HPLC-ELSD. This method provided a technology to evaluate the homogeneity and stability of Solanum nigrum L with wide application prospects and practical value.

Investigation of Pokemon-regulated proteins in hepatocellular carcinoma using mass spectrometry-based multiplex quantitative proteomics.

Pokemon is a transcription regulator involved in embryonic development, cellular differentiation and oncogenesis. It is aberrantly overexpressed in multiple human cancers including Hepatocellular carcinoma (HCC) and is considered as a promising biomarker for HCC. In this work, the isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics strategy was used to investigate the proteomic profile associated with Pokemon in human HCC cell line QGY7703 and human hepatocyte line HL7702. Samples were labeled with four-plex iTRAQ reagents followed by two-dimensional liquid chromatography coupled with tandem mass spectrometry analysis. A total of 24 differentially expressed proteins were selected as significant. Nine proteins were potentially up-regulated by Pokemon while 15 proteins were potentially down-regulated and many proteins were previously identified as potential biomarkers for HCC. Gene ontology (GO) term enrichment revealed that the listed proteins were mainly involved in DNA metabolism and biosynthesis process. The changes of glucose-6-phosphate 1-dehydrogenase (G6PD, up-regulated) and ribonucleoside-diphosphate reductase large sub-unit (RIM1, down-regulated) were validated by Western blotting analysis and denoted as Pokemon's function of oncogenesis. We also found that Pokemon potentially repressed the expression of highly clustered proteins (MCM3, MCM5, MCM6, MCM7) which played key roles in promoting DNA replication. Altogether, our results may help better understand the role of Pokemon in HCC and promote the clinical applications.

Pharmacokinetics and metabolite identification of a novel VEGFR-2 and Src dual inhibitor 6-chloro-2-methoxy-N-(2-methoxybenzyl) acridin-9-amine in rats by liquid chromatography tandem mass spectrometry.

A novel VEGFR-2 and Src dual inhibitor, 6-Chloro-2-methoxy-N-(2-methoxybenzyl) acridin-9-amine (MBAA), is a 9-aminoacridine derivative, but its pharmacokinetics and metabolism in body remain unknown. Using liquid chromatography tandem electrospray ionization mass spectrometry with the multiple reaction monitoring modes, we developed and validated a simple, rapid, sensitive and accurate technology for analyses of MBAA in the rat plasma, urine and bile. The micro samples were quickly prepared by 96-well plate. Chromatographic separation was performed on a C(18) column with gradient elution. High-quality linearity calibration curves were achieved over a concentration range of 1.00-3000 ng mL(-1). Intra- and inter-day precisions (RSD) were less than 8.5%, and accuracy (RE%) ranged from -2.9% to 12%. Extraction recoveries of MBAA were consistent with an average of 82.2-111.4% at three QC concentrations. When administered intravenously at a single dose of 2.0 mg kg(-1) to male SD rats, MBAA was rapidly eliminated with a T(1/2) of 0.9 ± 0.1h and AUC(0-t) of 369 ± 44.7 ng mL(-1). We identified four direct phase I and phase II metabolites by mass difference of molecular ions between metabolites and the parent compound. Various fragmentation patterns of MBAA were used to identify and characterize its metabolites. This LC-MS/MS analysis provides a useful approach to the pharmacokinetic and metabolic study of MBAA.

Metabolomics study of alcohol-induced liver injury and hepatocellular carcinoma xenografts in mice.

Alcohol abuse is one of the major causes of liver injury and a promoter for hepatocellular carcinoma (HCC). To understand the disease-associated metabolic changes, we investigated and compared the profiles of metabolites in nude mice with alcohol-induced liver injury or bearing a HCC xenograft (HCCX). Alcohol-induced liver injury was achieved by daily administration of grain liquor, and HCC xenografts were generated by subcutaneous inoculation of HepG2 cells in nude mice. Metabolites in serum samples were profiled by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS). The acquired data was analyzed by principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) to identify potential disease-specific biomarkers. Results showed that the phosphatidylcholine (PC) levels were significantly higher in both liver injury and HCCX mice compared with the control. Interestingly, lysophosphatidylcholines (LPCs) that contain saturated or monounsaturated fatty acids were reduced in both liver injury and HCCX mice, but polyunsaturated fatty acids LPCs were elevated in liver injury mice only. These data delineated the disease-related metabolic alterations of LPCs in liver injury and HCC, suggesting that the LPC profile in serum may be biomarkers for these two common liver diseases.

Copper-catalyzed aerobic oxidative intramolecular alkene C-H amination leading to N-heterocycles.

A copper-catalyzed aerobic oxidative intramolecular alkene C-H amination has been developed using readily available substituted 3-benzylidene-2-pyridin-2-ylmethyl-2,3-dihydro-isoindol-1-ones as the starting materials, and the corresponding N-heterocycles were obtained in good to excellent yields. This method should provide a new and useful strategy for constructing N-heterocycles.