Validation of HPLC and TLC analytical methods to determine radiochemical purity of 99mTc-cAbVCAM1-5, a new experimental radiotracer.

Cardiovascular diseases, including fatal myocardial infarctions from atheromatous plaques, are the primary global mortality cause. Detecting stenotic atheromatous plaques is possible through coronary angiography, but vulnerable plaques with eccentric remodeling are undetectable with current diagnostic methods. Addressing this challenge, our group developed a radiopharmaceutical drug targeting vascular cell adhesion molecule 1 (VCAM-1), radiolabeled with technetium-99m. Given the absence of a monograph in the European Pharmacopoeia, and in order to draft the investigational medicinal product documentation, analytical methods had to be validated by high performance liquid chromatography (HPLC) and thin layer chromatography (TLC) to determine the radiochemical purity (RCP) of 99mTc-cAbVCAM1-5. This study therefore presents the results of the validation of analytical methods obtained in this context. The method validation followed the European Association of Nuclear Medicine (EANM) recommendations adapted from ICH Q2(R1), ensuring conformity with specificity, accuracy, repeatability and intermediate precision, linearity, robustness, quantification limit (LoQ), and range criteria. Regarding the results of specificity, both HPLC and TLC methods demonstrated excellent separation of 99mTc-cAbVCAM1-5 from impurities 99mTcO4-. Accuracy results indicated recovery percentages within the range of 99.52-101.40% for the HPLC and 99.51-101.97% for TLC, ensuring reliable measurements for each concentration of 99mTcO4-. Precision of the methods was validated by assessing repeatability and intermediate precision. Linearity was determined over the usual concentrations range and the correlation coefficient was greater than 0.99 for both methods. The limit of quantification was measured by diluting the 99mTcO4- to obtain a signal-to-noise ratio of around 10:1. Under these conditions, we obtained an LOQ of 2.10 MBq/mL for HPLC and 2Mbq/mL for TLC. In conclusion, the analytical methods developed in this study comply with EANM recommendations. This therefore allows us to correctly assess the radiochemical purity of 99mTc-cAbVCAM1-5, a new radiotracer targeting inflammation in vulnerable plaques.

Exploring the potential of a Ephedra alata leaf extract: Phytochemical analysis, antioxidant activity, antibacterial properties, and green synthesis of ZnO nanoparticles for photocatalytic degradation of methylene blue.

Ephedra alata leaf extracts have therapeutic properties and contain various natural compounds known as phytochemicals. This study assessed the phytochemical content and antioxidant effects of a Ephedra alata leaf extract, as well as zinc oxide (ZnO) nanoparticle production. The extract contained phenolic acids, including vanillic acid, chlorogenic acid, gallic acid, p-coumaric acid, vanillin and rutin. Its total phenolic content and total flavonoid content were 48.7 ± 0.9 mg.g-1 and 1.7 ± 0.4 mg.g-1, respectively. The extract displayed a DPPH inhibition rate of 70.5%, total antioxidant activity of 49.5 ± 3.4 mg.g-1, and significant antimicrobial activity toward Gram-positive and negative bacteria. The synthesized ZnO nanoparticles had spherical shape, crystallite size of 25 nm, particle size between 5 and 30 nm, and bandgap energy of 3.3 eV. In specific conditions (90 min contact time, pH 7, and 25°C), these nanoparticles efficiently photodegraded 87% of methylene blue, suggesting potential applications for sustainable water treatment and pollution control.

Preparation of magnetic amphiphilic resin microspheres via the one-step polymerization method and extraction of four glucocorticoids for HPLC-MS analysis.

Amphiphilic materials can be used for sample preparation of chromatography or mass spectrometry. Amphiphilic materials with magnetic properties in combination with magnetic suction devices allow for automated sample preparation. However, conventional synthesis methods are cumbersome and not suitable for the mass production of the material. In this study, a micro-suspension polymerization method was developed to synthesize magnetic amphiphilic resin microspheres (MARMs), providing new ideas for the preparation of amphiphilic microspheres. MARMs with particle sizes ranging from 3 to 6 µm were successfully prepared, with BET surface area up to 653.2 m2/g. A magnetic solid-phase extraction method based on MARM-5 was developed for the extraction of four glucocorticoids including Cortisone, Hydrocortisone, Cortodoxone, and Corticosterone. This method had a very short adsorption time of 0.5 min and a total extraction time of only 13 min. The limit of detection for the four glucocorticoids ranged from 0.22 to 0.82 ng/L. There was a good linear relationship between sample concentration and peak area in the range of 25∼500 ng/L. Relative recovery of 98 %∼108 % and internal standard normalized matrix effect factors of 95∼114 % were obtained, and the relative standard deviation was between 2.3 % and 6.3 %. The MARMs would be used as excellent solid extraction material for glucocorticoids.

A low-cost efficient online derivatization system for the determination of saccharides by high-performance liquid chromatograph-ultraviolet detector.

In this study, a low-cost efficient online derivatization system was developed which allows for the detection of various types of mono- and oligo-saccharides only utilizing high-performance liquid chromatography (HPLC)-ultraviolet detector (UV) system. In the proposed method, phenylhydrazine was used as the derivatization reagent and directly spiked in the mobile phase, allowing for the separation and detection of mono- and oligosaccharides in an accessible instrument system (HPLC-UV). And the online derivatization design of the proposed method has significantly reduced the potential harm of derivatization reagents to the analysts. Furthermore, critical chromatographic parameters were optimized via the Box-Behnken design strategy, culminating in the ideal response for saccharides. Finally, the methodology validation of the proposed method was conducted. The proposed method showed satisfactory linear ranges with acceptable correlation coefficients (R2  > 0.99), outstanding accuracy (Recovery: 95.3%-105.6%), high intra-day precision (relative standard deviation [RSD]: 1.4%-7.1%) and inter-day precision (RSD: 2.0%-7.4%). The robustness and ruggedness of the proposed method were proved as the recovery values in the range of 95.0%-104.6% and 95.1%-104.8% for robustness and ruggedness, respectively. These satisfactory validation results confirm the applicability and reliability of the proposed method for the analysis of saccharides in various complex real-world samples.

Effectiveness of resveratrol as a hepatoprotector in a rat model of paracetamol-induced liver injury / Eficácia do resveratrol como hepatoprotetor em modelo de rato com lesão hepática induzida por paracetamol

Objective: Evaluate the effectiveness of resveratrol as a hepatoprotector in a rat model of paracetamol-induced liver injury and its biodistribution to understand its pharmacokinetics. Methodology: As an experimental approach, animals were divided into the test group with 4 subgroups and the control group with 4 subgroups. Animals of the "treated" group were subjected to resveratrol pre-treatment for eight days, followed by intoxication with a high dose of paracetamol on the 8th day. Animals were euthanized to collect the blood and liver tissue samples 24 and 72 h after the last administration. Hepatoprotective activity was evaluated through serum levels of glycogen and hepatic enzymes, such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP), histological and morphometric analysis of the liver tissue. For biodistribution analysis, different organs (organs, kidneys, heart and lungs) were collected and macerated, and resveratrol was quantified using high-performance liquid chromatography. Statistical analyses of morphometry, transaminases and alkaline phosphatase measurements, and biodistribution results were performed using GraphPad Prism® 3.0. Differences between groups were compared using ANOVA, followed by the Bonferroni test. Statistical significance was set at p < 0.05. Results: Resveratrol has a hepatoprotective action against acute intoxication by paracetamol, as evidenced by the histological decrease in necrosis and inflammatory foci, preservation of glycogen and other 1,2-glycols in zone 3, and reduction of serum ALT and AST levels. An increased presence of collagen was observed in acinar zones 1 and 3 with picrosirius red staining; therefore, quantification was performed in these regions showing smaller collagen areas in the R and RP groups than in the PC and NC groups Paracetamol caused a significant reduction in the resveratrol concentration in serum and the organs studied, indicating that the antioxidant activity of resveratrol is related to its hepatoprotective action. Conclusion: Resveratrol has hepatoprotective properties and can mitigate some of the liver damage caused by high doses of paracetamol, as indicated by changes in tissue characteristics and liver enzyme levels.

Objetivo: Avaliar a eficácia do resveratrol como hepatoprotetor em modelo de rato com lesão hepática induzida por paracetamol e sua biodistribuição para compreender sua farmacocinética. Metodologia: Como abordagem experimental, os animais foram divididos em grupo teste com 4 subgrupos e grupo controle com 4 subgrupos. Os animais do grupo "tratado" foram submetidos ao pré-tratamento com resveratrol durante oito dias, seguido de intoxicação com alta dose de paracetamol no oitavo dia. Os animais foram eutanasiados para coleta de amostras de sangue e tecido hepático 24 e 72 horas após a última administração. A atividade hepatoprotetora foi avaliada através dos níveis séricos de glicogênio e de enzimas hepáticas, como aspartato aminotransferase (AST), alanina aminotransferase (ALT) e fosfatase alcalina (ALP), análise histológica e morfométrica do tecido hepático. Para análise de biodistribuição, diferentes órgãos (órgãos, rins, coração e pulmões) foram coletados e macerados, e o resveratrol foi quantificado por cromatografia líquida de alta eficiência. Análises estatísticas de morfometria, medidas de transaminases e fosfatase alcalina e resultados de biodistribuição foram realizadas utilizando GraphPad Prism® 3.0. As diferenças entre os grupos foram comparadas por meio de ANOVA, seguida do teste de Bonferroni. A significância estatística foi estabelecida em p < 0,05. Resultados: O resveratrol tem ação hepatoprotetora contra a intoxicação aguda por paracetamol, evidenciada pela diminuição histológica da necrose e dos focos inflamatórios, preservação do glicogênio e outros 1,2-glicóis na zona 3 e redução dos níveis séricos de ALT e AST. Foi observada presença aumentada de colágeno nas zonas acinares 1 e 3 com coloração picrosirius red; portanto, foi realizada quantificação nessas regiões mostrando menores áreas de colágeno nos grupos tratados com resveratrol e resveratrol associado com paracetamol do que nos grupos controles positivo e negativo. O paracetamol causou redução significativa na concentração de resveratrol no soro e nos órgãos estudados, indicando que a atividade antioxidante do resveratrol está relacionada à sua ação hepatoprotetora. Conclusão: O resveratrol possui propriedades hepatoprotetoras e pode mitigar alguns dos danos hepáticos causados por altas doses de paracetamol, conforme indicado por alterações nas características dos tecidos e nos níveis de enzimas hepáticas.

Organophosphate esters cause thyroid dysfunction via multiple signaling pathways in zebrafish brain.

Organophosphate esters (OPEs) are widespread in various environmental media, and can disrupt thyroid endocrine signaling pathways. Mechanisms by which OPEs disrupt thyroid hormone (TH) signal transduction are not fully understood. Here, we present in vivo-in vitro-in silico evidence establishing OPEs as environmental THs competitively entering the brain to inhibit growth of zebrafish via multiple signaling pathways. OPEs can bind to transthyretin (TTR) and thyroxine-binding globulin, thereby affecting the transport of TH in the blood, and to the brain by TTR through the blood-brain barrier. When GH3 cells were exposed to OPEs, cell proliferation was significantly inhibited given that OPEs are competitive inhibitors of TH. Cresyl diphenyl phosphate was shown to be an effective antagonist of TH. Chronic exposure to OPEs significantly inhibited the growth of zebrafish by interfering with thyroperoxidase and thyroglobulin to inhibit TH synthesis. Based on comparisons of modulations of gene expression with the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases, signaling pathways related to thyroid endocrine functions, such as receptor-ligand binding and regulation of hormone levels, were identified as being affected by exposure to OPEs. Effects were also associated with the biosynthesis and metabolism of lipids, and neuroactive ligand-receptor interactions. These findings provide a comprehensive understanding of the mechanisms by which OPEs disrupt thyroid pathways in zebrafish.

Methods to determine the quality of acid oils and fatty acid distillates used in animal feeding.

Acid oils and fatty acid distillates are by-products from the refining of edible oils and fats. They are used as feed ingredients, but their highly variable composition sometimes affects the productive parameters of the animals. Thus, their quality control and standardization are necessary. The official methods recommended for crude and refined fats and oils must be modified to give reliable results when applied to acid oils and fatty acid distillates. This article summarizes the drawbacks that were encountered during the setup of the analytical methods and how were they overcome by adapting the methods to these type of fat samples. Some methods such as the determinations of fatty acid composition, tocopherol and tocotrienol content, unsaponifiable matter, acidity and peroxide value had to be minimally adapted. However, others such as the determinations of moisture and volatile matter, insoluble impurities, lipid classes and p-anisidine value showed important drawbacks that required a more significant adaptation.•All the analytical methods have been successfully applied to acid oils and fatty acid distillates.•A detailed description of the sample preparation for analysis and applied analytical methods is provided as a compendium of methods in the supplementary material.•These methods will be extremely useful to improve the quality control of these heterogeneous feed ingredients.

Triazine-triphenylphosphine based porous organic polymer as sorbent for solid phase extraction of nitroimidazoles from honey and water.

A triazine-based porous organic polymer was prepared by facile solvothermal polymerization with cyanuric chloride and triphenyl phosphine as functional monomers. The polymer was characterized and then used for the first time as the sorbent for the effective solid-phase extraction of some nitroimidazoles (NDZs) (metronidazole, ronidazole, secnidazole, dimetridazole and ornidazole). The main experimental influencing parameters for the extraction including the eluent solvent, eluent volume, sample loading rate, sample solution pH, salt concentration and sample volume were investigated. The adsorption kinetics and adsorption isotherms were investigated to elucidate the possible adsorption mechanism. With the triazine-based porous organic polymer as the SPE adsorbent, trace NDZs were effectively extracted. The good enrichment capability for the NDZs was mainly attributed to the hydrogen binding interactions by the aromatic 1,3,5-trizine rings. After the SPE, the extracted analytes were analyzed by high-performance liquid chromatograph with ultraviolet detection. Under the selected conditions, the method had a good linear response for the analytes in the range of 0.06-120 ng mL-1 for water and 1.5-1200 ng g-1 for honey samples. The limits of detections (S/N=3) fell in the range of 0.02-0.06 ng mL-1 for water and 0.5-1.5 ng g-1 for honey samples. The method recoveries for the analytes for spiked samples were in the range of 80.3-118%. The method can be applied for the determination of the NDZs from real samples.

Integrated UPLC-MS and Network Pharmacology Approach to Explore the Active Components and the Potential Mechanism of Yiqi Huoxue Decoction for Treating Nephrotic Syndrome.

Background: Yiqi Huoxue Decoction (YQHXD) is a traditional Chinese medicine that promotes blood circulation, removes blood stasis, facilitates diuresis, and alleviates edema. It is composed of 10 herbal medicines and has extensive application in treating nephrotic syndrome (NS). However, the active components and the potential mechanism of YQHXD for treating NS remain unclear. Methods: We set up a sensitive and rapid method based on Ultra-High Performance Liquid Chromatograph-Mass (UPLC-MS) to identify the compounds in YQHXD and constituents absorbed into the blood. Disease genes were collected through GeneCards, DisGeNET, and OMIM database. Genes of compounds absorbed into blood were predicted by the TCMSP database. We constructed Disease-Drug-Ingredient-Gene (DDIG) network using Cytoscape, established a Protein-protein interaction (PPI) network using String, Gene biological process (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed using DAVID. Cellular experiments were performed to validate the results of network pharmacology. Result: A total of 233 compounds in YQHXD and 50 constituents absorbed into the blood of rats were identified. The 36 core targets in the PPI network were clustered in the phosphatidylinositol 3 kinase-RAC serine/threonine-protein kinase (PI3K-AKT) and nuclear factor kappa-B (NF-κB) signaling pathways. Luteolin, Wogonin, Formononetin, and Calycosin were top-ranking components as potentially active compounds. Conclusion: The results of our studies show that YQHXD is able to enhance renal function, alleviate podocyte injury, and improve adriamycin nephrotic syndrome.

OnabotulinumtoxinA Displays Greater Biological Activity Compared to IncobotulinumtoxinA, Demonstrating Non-Interchangeability in Both In Vitro and In Vivo Assays.

Differences in botulinum neurotoxin manufacturing, formulation, and potency evaluation can impact dose and biological activity, which ultimately affect duration of action. The potency of different labeled vials of incobotulinumtoxinA (Xeomin®; 50 U, 100 U, or 200 U vials; incobotA) versus onabotulinumtoxinA (BOTOX®; 100 U vial; onabotA) were compared on a unit-to-unit basis to assess biological activity using in vitro (light-chain activity high-performance liquid chromatography (LCA-HPLC) and cell-based potency assay (CBPA)) and in vivo (rat compound muscle action potential (cMAP) and mouse digit abduction score (DAS)) assays. Using LCA-HPLC, incobotA units displayed approximately 54% of the protease activity of label-stated equivalent onabotA units. Lower potency, reflected by higher EC50, ID50, and ED50 values (pooled mean ± SEM), was displayed by incobotA compared to onabotA in the CBPA (EC50: incobotA 7.6 ± 0.7 U/mL; onabotA 5.9 ± 0.5 U/mL), cMAP (ID50: incobotA 0.078 ± 0.005 U/rat; onabotA 0.053 ± 0.004 U/rat), and DAS (ED50: incobotA 14.2 ± 0.5 U/kg; onabotA 8.7 ± 0.3 U/kg) assays. Lastly, in the DAS assay, onabotA had a longer duration of action compared to incobotA when dosed at label-stated equivalent units. In summary, onabotA consistently displayed greater biological activity than incobotA in two in vitro and two in vivo assays. Differences in the assay results do not support dose interchangeability between the two products.

Determination of related substances in carbaindoline hydrochloride tablets by HPLC / 国际药学研究杂志

Objective: To establish a high performance liquid chromatography(HPLC)method for determination of the related substances of carbaindoline hydrochloride tablets. Methods: HPLC was performed on an octadecylsilane bonded silica gel column. The mobile phase was acetonitrile/0.01 mol/L KH2PO4 solution in a gradient elution. The flow rate was 1.0 ml/min. Column temperature was 25℃. Injection volume was 10 μl. The detection wavelength was 210 nm. Methodological verification was carried out and the changes of related substances under different influencing conditions were investigated using the verified method. Results: The carbaindoline hydrochloride and related substances were all well separated under the conditions of the established method. The limit of detection(LOD)and quantitation(LOQ)of the method were 0.5 ng and 1.5 ng, respectively. The calibration curve was linear in the range of 2.0-7.0 μg/ml(r=0.9995). The RSD of reproducibility was 0.05%. The carbaindoline hydrochloride tablets showed colored changes with a significant increase of related substances under light illumination or at higher temperature of 60℃. Conclusion: The established method is simple, acurate, sensitive and specific, which might be used for the determination of related substances in carbaindoline hydrochloride tablets. The carbaindoline hydrochloride tablets produced more impurities under the light illumination or at the higher temperature, which indicates that they should be stored at room temperature avoiding light.

N-Acetyl cysteine ameliorates hyperglycemia-induced cardiomyocyte toxicity by improving mitochondrial energetics and enhancing endogenous Coenzyme Q9/10 levels.

The diabetic heart has been linked with reduced endogenous levels of coenzyme Q9/10 (CoQ), an important antioxidant and component of the electron transport chain. Although CoQ has displayed cardioprotective potential in experimental models of diabetes, the impact of N-acetyl cysteine (NAC) on mitochondrial energetics and endogenous levels of CoQ remains to be clarified. To explore these effects, high glucose-exposed H9c2 cardiomyocytes were used as an experimental model of hyperglycemia-induced cardiac injury. The results showed that high glucose exposure caused an increased production of reactive oxygen species (ROS), which was associated with impaired mitochondrial energetics as confirmed by a reduction of maximal respiration rate and depleted ATP levels. These detrimental effects were consistent with significantly reduced endogenous CoQ levels and accelerated cell toxicity. Although metformin demonstrated similar effects on mitochondrial energetics and cell viability, NAC demonstrated a more pronounced effect in ameliorating cytosolic and mitochondrial ROS production. Interestingly, the ameliorative effects of NAC against hyperglycemia-induced injury were linked with its capability to enhance endogenous CoQ levels. Although such data are to be confirmed in other models, especially in vivo studies, the overall findings provide additional evidence on the therapeutic mechanisms by which NAC protects against diabetes-induced cardiac injury.

Quantification of In Vitro Protein Lysine Acetylation by Reversed Phase HPLC.

Protein lysine acetylation is a reversible posttranslational modification that is catalyzed by a group of enzymes that are collectively referred to as lysine (K) acetyltransferases (KATs). These enzymes catalyze the transfer of the acetyl group from acetyl coenzyme A (Ac-CoA) to the ε-amino group of lysine amino acid. Protein lysine acetylation plays a critical role in the regulation of important cellular processes and it is therefore paramount that we understand the catalytic mechanisms of these enzymes. While there is a variety of methods that have been developed to analyze the enzymatic properties of KATs, majority of the proposed methods have considerable limitations. We describe here a reversed phase HPLC based method that monitors substrate consumption and product formation simultaneously. This method is highly reproducible and optimally suited for the determination of accurate kinetic parameters of KATs.

Determination of Eupatilin in Folium artemisiae Argyi and Its Inhibitory Effect on Hepatoma Cells.

AIM: The aim of this study is to establish a method for determination of eupatilin in Folium artemisiae Argyi and observe the inhibitory effect of Folium artemisiae Argyi extract on human hepatoma SMMC-7721 cells. METHODS: High-performance liquid chromatograph system with 2910 pump, 2930 UV detector, and N2000 workstation was used for determination of eupatilin in Folium artemisiae Argyi. Human hepatoma SMMC-7721 cells were cultured and cell proliferation was measured using the MTT assay. The expression protein levels of p53, Topo II, and bcl-2 were detected using Western blotting. RESULTS: Eupatilin exhibited a linearity range of 0.5-3.0 µg/mL and a recovery of 100.72%, relevant standard derivation = 2.28%. Folium artemisiae Argyi extract had marked cytostatic and cytotoxic effects on SMMC-7721 cells, inhibited the SMMC-7721 colony formation in a dose-dependent manner. Folium artemisiae Argyi extract already possessed delayed effect after treating SMMC-7721 cells for 8 h, which became obvious at 12 h from treatment. After drug withdrawal, cells still tended to apoptosis. Folium artemisiae Argyi extract could inhibit p53, Topo II, and bcl-2 expressions in tumor cells. The present method for determination of eupatilin is simple, fast, accurate, sensitive, and reproducible. CONCLUSION: Hepatoma SMMC-7721 cells are quite sensitive to Folium artemisiae Argyi extract, which may be associated with its suppression of p53, Topo II, and bcl-2 expressions. SUMMARY: The study aimed to establish a method for determination of eupatilin in Folium artemisiae Argyi and observe the inhibitory effect of Folium artemisiae Argyi extract on human hepatoma SMMC-7721 cells. The results suggested that the present method for determination of eupatilin is simple, fast, accurate, sensitive, and reproducible. Hepatoma SMMC-7721 cells are quite sensitive to Folium artemisiae Argyi extract, which may be associated with its suppression of p53, Topo II, and bcl-2 expressions. Abbreviations used: HPLC: High-performance liquid chromatograph; OD: Optical density; RSD: Relevant standard derivation; IC50: Inhibitory 50% concentration.

Comprehensive analysis of Polygoni Multiflori Radix of different geographical origins using ultra-high-performance liquid chromatography fingerprints and multivariate chemometric methods.

Polygoni Multiflori Radix (PMR) is increasingly being used not just as a traditional herbal medicine but also as a popular functional food. In this study, multivariate chemometric methods and mass spectrometry were combined to analyze the ultra-high-performance liquid chromatograph (UPLC) fingerprints of PMR from six different geographical origins. A chemometric strategy based on multivariate curve resolution-alternating least squares (MCR-ALS) and three classification methods is proposed to analyze the UPLC fingerprints obtained. Common chromatographic problems, including the background contribution, baseline contribution, and peak overlap, were handled by the established MCR-ALS model. A total of 22 components were resolved. Moreover, relative species concentrations were obtained from the MCR-ALS model, which was used for multivariate classification analysis. Principal component analysis (PCA) and Ward's method have been applied to classify 72 PMR samples from six different geographical regions. The PCA score plot showed that the PMR samples fell into four clusters, which related to the geographical location and climate of the source areas. The results were then corroborated by Ward's method. In addition, according to the variance-weighted distance between cluster centers obtained from Ward's method, five components were identified as the most significant variables (chemical markers) for cluster discrimination. A counter-propagation artificial neural network has been applied to confirm and predict the effects of chemical markers on different samples. Finally, the five chemical markers were identified by UPLC-quadrupole time-of-flight mass spectrometer. Components 3, 12, 16, 18, and 19 were identified as 2,3,5,4'-tetrahydroxy-stilbene-2-O-ß-d-glucoside, emodin-8-O-ß-d-glucopyranoside, emodin-8-O-(6'-O-acetyl)-ß-d-glucopyranoside, emodin, and physcion, respectively. In conclusion, the proposed method can be applied for the comprehensive analysis of natural samples.

Simultaneous Determination of Eight Kinds of Neurotransmitters in Rat Blood Serum by Ultra-high Performance Liquid Chromatograph- Tandem Mass Spectrometry / 分析化学

An ultra-high performance liquid chromatography tandem mass spectrometric ( LC-MS/MS ) method for simultaneous determination of 8 kinds of neurotransmitters (5-HT, GABA, Glu, ACH, NE, DA, 5-HIAA, HVA) in rat serum was developed.The blood samples were extracted by 0.1% formic acid in acetonitrile and separated on a Waters ACQUITY UPLC BEH C18(2.1 mm×100 mm, 1.7 μm) using gradient elution, with the mobile phase consisting of acetonitrile and 0.1% formic acid in water.The samples were then ioniZed with positive electrospray ( ESI+) , and detected under multiple reaction monitoring ( MRM ) mode.As a result, 8 kinds of neurotransmitters were determined accurately in 10 min with a limit of quantitation of 1.8 ng/mL and intra-day and inter-day precisions of ≤9.2% ( n=6 ).This method showed a good linearity in detection of neurotransmitters and the linear correlation coefficients were greater than 0.994.Also the stability, recovery and matrix effect were eligible for the analysis.This method showed high accuracy, sensitivity, strong specificity, good stability, small matrix effect and short time for analysis, and was suitable for the quantitative determination of monoamine, amino acids and acetylcholine neurotransmittes in rat serum.

HPLC fucoxanthin profiles of a microalga, a macroalga and a pure fucoxanthin standard.

Data in this article illustrate representative fucoxanthin chromatograms of a microalga, Chaetoceros calcitrans; a macroalga, Saccharina japonica and; a pure fucoxanthin standard. High performance liquid chromatography (HPLC) eluted fucoxanthin at the 7.008±0.024th min. This data article refers to the research article ''Antioxidant capacities of fucoxanthin-producing algae as influenced by their carotenoid and phenolic contents'' Foo et al. [1]; where a more comprehensive data interpretation and analysis is explained.

[Determination of indigo and brilliant blue in different types of food products by high performance liquid chromatography with solid phase extraction].

OBJECTIVE: To develop and validate a solid phase extraction-high performance liquid chromatographic( SPE-HPLC) method for the simultaneous determination of indigo and brilliant blue in different types of food products. METHODS: The artificial colors in food products were extracted by acetonitrile / water and purified by WAX SPE cartridges, The separation was achieved using a Waters Symmetry C_(18)( 5 µm, 4. 6 mm × 250 mm) column and a binary gradient mobile phase of methanol and 0. 02 mol/L ammonium acetate solution, detected by HPLC-PDA. RESULTS: The validated analytical method showed that there was a good linearity in the range of 0. 05- 20. 00 µg/mL for both indigo and brilliant blue( r > 0. 999). The lowest detection limits of indigo and brilliant blue were 0. 04 and 0. 02 mg/kg, respectively. The average recoveries were among 81. 8%- 101. 1%, with relative standard deviation( RSD) of 2. 1%- 4. 9%( n =6) for both artificial colors. CONCLUSION: The method has high selectivity, high sensitivity, good recovery and reproducibility. It is suitable to simultaneously monitor indigo and brilliant blue in several types of food products based on the food classification system of GB 2760-2014.

Sea buckthorn (Hippophae rhamnoides L.) vegetative parts as an unconventional source of lipophilic antioxidants.

The profile of lipophilic antioxidants in different vegetative parts (leaves, shoots, buds and berries) was studied in sea buckthorn (Hippophae rhamnoides L.) male and female plants collected in the end of spring. Five lipophilic compounds, i.e. three tocopherol homologues (α, ß and γ), plastochromanol-8 and ß-carotene, were identified in each vegetative part of male and female sea buckthorn plants at the following concentrations: 7.25-35.41, 0.21-2.43, 0.41-1.51, 0.19-1.79 and 4.43-24.57 mg/100 g dry weight basis. Additionally, significant amounts of α-tocotrienol (1.99 mg/100 g dry weight basis) were detected in buds. The α-tocopherol and ß-carotene were predominant lipophilic antioxidants in each vegetative part, accounting for 78.3-97.0% of identified compounds. The greatest amounts of lipophilic antioxidants were found in leaves, especially of female plants. Nevertheless, apart from leaves, also shoots of plants of both sexes seem to be a good source of α-tocopherol and ß-carotene.

Determination of PA-824 in Rat Plasma by HPLC-MS/MS and Application in Pharmaco-kinetic Study / 医药导报

Objective To develop an HPLC-MS/ MS method for quantitative determination of PA-824 in rat plasma and to study the pharmacokinetics of PA-824 in rat after oral administration. Methods An HPLC-MS/ MS method was developed and validated for determination of PA-824 in rat plasma using metronidazole as internal standard.The proteins in plasma samples were precipitated with methanol,and PA-824 was enriched for analysis by HPLC-MS/ MS.An Inertsil? ODS3 C18 column (150 mm×4.6 mm,5 μm) was applied with mobile phase composed of methanol- 0.03% triethylamine (TEA) in water (90:10) ,at a flow rate of 0. 5 mL ? min-1 and column temperature of 30 ℃ . Quantitation was performed on a triple quadrupole mass spectrometer applying electrospray ionization technique and operating in multiple reaction monitoring (MRM) and positive ion mode with transitions at 360.1/ 175.0 for PA-824 and 172.0/ 128.0 for metronidazole.The concentration of PA-824 in plasma was tested after oral administration at various time points and the data were processed with software DAS.2.0. Results The standard calibration curve for spiked rat plasma containing PA-824 was linear over the range of 0. 1 - 10. 0 μg?mL-1 . The recoveries obtained for PA-824 were greater than 92.13%.Intra-day and inter-day coefficient of variation were less than 6.6%.After oral administration,the main pharmacokinetic parameters were AUC(0-t) : ( 3 297. 503 ± 320. 958) mg ? L-1 ? min-1 , AUC(0-∞ ) :(3 558.315±338.860)mg?L-1?min-1 ,tmax:(360.000±64.143)min,Cmax:(3.5±0.3)μg?mL-1 . Conclusion The method is rapid,accurate,simple,and successfully applied in a pharmacokinetic study of fixed dose oral administration of PA-824 in rats.