Effects of high-altitude environment on pharmacokinetic parameters of gliquidone in rats.

OBJECTIVE: To investigate the effect of high-altitude hypoxia on the pharmacokinetics parameters of gliquidone. METHODS: Twelve healthy male Wistar rats were randomly divided into plain group and high-altitude group with 6 rats in each group. Blood samples were collected after intragastric administration of gliquidone (6.3 mg/kg). Ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) was used to determine the concentration of gliquidone in rat plasma samples. And the expression of CYP2C9 in rat liver tissues was determined by Western blotting. RESULTS: Compared with the plain group, the peak concentration of gliquidone in the high-altitude rats was significantly increased, the absorption rate constant was decreased, the elimination rate constant and the absorption half-life were increased, the elimination half-life was shortened, the mean residence time and apparent volume of distribution were decreased (all P<0.05). Western blotting showed that the expression of CYP2C9 was significantly up-regulated in the liver tissues of high altitude group rats, compared with the plain group (4.18 ±0.06 vs. 2.13±0.06, t=11.57, P<0.01). CONCLUSION: Under the high-altitude hypoxia environment, the absorption of gliquidone in rats was reduced and the metabolism was accelerated in rats, which may be related to the up-regulation of CYP2C9 expression in liver tissues.

The effect of cooling procedures on monomer elution from heat-cured polymethyl methacrylate denture base materials

Abstract Objective To evaluate the amount of methyl methacrylate (MMA) released in water from heat-cured polymethyl methacrylate (PMMA) denture base materials subjected to different cooling procedures. Methodology Disk-shaped specimens (Ø:17 mm, h:2 mm) were fabricated from Paladon 65 (PA), ProBase Hot (PB), Stellon QC-20 (QC) and Vertex Rapid Simplified (VE) denture materials using five different cooling procedures (n=3/procedure): A) Bench-cooling for 10 min and then under running water for 15 min; B) Cooling in water-bath until room temperature; C) Cooling under running water for 15 min; D) Bench-cooling, and E) Bench-cooling for 30 min and under running water for 15 min. A, B, D, E procedures were proposed by the manufacturers, while the C was selected as the fastest one. Control specimens (n=3/material) were fabricated using a long polymerization cycle and bench-cooling. After deflasking, the specimens were ground, polished and stored in individual containers with 10 ml of distilled water for seven days (37oC). The amount of water-eluted MMA was measured per container using isocratic ultra-fast liquid chromatography (UFLC). Data were analyzed using Student's and Welch's t-test (α=0.05). Results MMA values below the lower quantification limit (LoQ=5.9 ppm) were registered in B, C, E (PA); E (PB) and B, D, E (QC) procedures, whereas values below the detection limit (LoD=1.96 ppm) were registered in A, D (PA); A, B, C, D (PB); C, D, E (VE) and in all specimens of the control group. A, B (VE) and A, C (QC) procedures yielded values ranging from 6.4 to 13.2 ppm with insignificant differences in material and procedure factors (p>0.05). Conclusions The cooling procedures may affect the monomer elution from denture base materials. The Ε procedure may be considered a universal cooling procedure compared to the ones proposed by the manufacturers, with the lowest residual monomer elution in water.

[Determination of trace low molecular mass aldehydes in air by ultra-fast liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a rapid and accurate method for the determination of trace acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde in the air by ultra-fast liquid chromatography-tandem mass spectrometry(UFLC-MS/MS). METHODS: The air sample was concentrated and derivatived by 3-methyl-2(3 H)-benzothiazolonhydrazone(MBTH), and the effect of derivative conditions including the concentration of MBTH, the pH, the derivative time and temperature was investigated. The stability of derivatives, the cracking mechanism of mass spectrometry, the matrix effect of the method and air sampling efficiency were studied. The chromatographic separation was carried out on a Shim-pack XR-ODS II column(100 mm×2. 0 mm, 2. 2 µm) by using water/methanol solution as the mobile phase with the gradient elution. Detection was performed in positive multi-reaction monitoring(MRM) mode for quantification by using external standard method. RESULTS: The four analytes showed good linear relationship within the range of 1. 00-100 µg/L(calculated by aldehyde) with a correlation coefficient r≥0. 9990. The limits of quantitation(LOQs) of the method(concentrated with 10 L air) were 0. 5 µg/m~3 in air, for acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde. The recoveries of the method were 90. 6%-97. 8% at the three spiked levels, and the relative standard deviations(RSDs) were between 1. 9%-6. 4%(n=6), the average sampling efficiency was between 91. 0%-97. 1%. CONCLUSION: The developed method is simple, less interference and specificity, and is suitable for the simultaneous rapid determination of trace acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde in air of work place.

Analytical Quality by Design Based Systematic Development and Optimization of a Sensitive Bioanalytical Method for Estimation Cinacalcet HCl in Rabbit Serum.

Context: There is no straightforward method for estimating cinacalcet HCl in biological materials such as serum exists. As a result, the goal of this research is to develop a simple quality by design (QbD) enabled reverse phase-Ultra-Fast Liquid Chromatography (RP-UFLC) model for analyzing cinacalcet HCl in serum. Aim: The current study envisages the development and validation of an isocratic simple, precise, and rapid QbD enabled RP-UFLC method for the quantification of cinacalcet HCl in both solution form and blood samples. Subjects and Methods: The optimum conditions were outlined, selecting three influential factors (CMPs) i.e., mobile phase composition, flow rate, and injection volume. Systematic optimization was performed by 32-Box Benkhen experimental design using response surface methodology. The selected variables are further assessed for observed responses Critical Analytical attributes, i.e., peak area, retention time (Rt), USP Plate count. The optimized method used a chromatographic C18 (100 mm × 4.6 mm i.d) column with mobile phase (acetonitrile and Tetrabutyl Ammonium Hydrogen Sulphate [TBSH]) in the ratio of 1:1, with a flow rate of 1 mL/min with UV at λmax 223 nm. The developed method was found to be specific for cinacalcet HCl, enduring no interference of peaks with an overall analytical Rt of 4.3 min. Results: The Accuracy reported as % recovery was found to be 96.83%-101.32% and 95.18%-102.49% respectively. Inter-day precision (reproducibility) and intra-day precision (repeatability) were found to be 0.22-1.19 standard deviation (SD) and 0.14-2.12 SD respectively. The calibration curve was found to be linear with a regression equation Y = 195.8x + 21852, with R 2 0.999 over a concentration range from 100 to 100,000 ng/mL. Conclusion: The required detection and quantitation limits (Limit of Detection and Limit of Quantitation) values were obtained within the acceptance limit based on S/N ratio which indicates the method was sensitive and rapidity of the method. Further, the developed QbD enabled UFLC method was approved and effectively entreated the blood tests to study the pharmacokinetic parameters which indicate a robust, accurate cost-effective method intended for quality control tool for routine systematic analysis in research labs.

Fumonisin B1 Production by Fusarium Species and Mycotoxigenic Effect on Larval Zebrafish.

Fumonisin B1 (FB1) is a common mycotoxin produced by Fusarium species particularly F. proliferatum and F. verticillioides. The toxin produced can cause adverse effects on humans and animals. The objectives of this study were to detect the production of FB1 based on the amplification of FUM1 gene, to quantify FB1 produced by the isolates using Ultra-fast Liquid Chromatography (UFLC) analysis, to examine the embryotoxicity effect of FB1 and to determine EC50 toward the larvae of zebrafish (Danio rerio). Fifty isolates of Fusarium species were isolated from different hosts throughout Malaysia. Successful amplification of the FUM1 gene showed the presence of this gene (800 bp) in the genome of 48 out of 50 isolates. The highest level of FB1 produced by F. proliferatum isolate B2433 was 6677.32 ppm meanwhile F. verticillioides isolate J1363 was 954.01 ppm. From the assessment of embryotoxicity test of FB1 on larvae of zebrafish, five concentrations of FB1 (0.43 ppm, 0.58 ppm, 0.72 ppm, 0.87 ppm and 1.00 ppm) were tested. Morphological changes of the FB1 exposed-larvae were observed at 24 to 168 hpf. The mortality rate and abnormality of zebrafish larvae were significantly increased at 144 hpf exposure. Meanwhile, the spontaneous tail coiling showed a significant difference. There were no significant differences in the heartbeat rate. As a conclusion, the presence of FUM1 in every isolate can be detected by FUM1 gene analysis and both of the species produced different concentrations of FB1. This is the first report of FB1 produced by Fusarium species gave a significant effect on zebrafish development.

Simultaneous detection and quantification of 57 compounds in Spatholobi Caulis applying ultra-fast liquid chromatography with tandem mass spectrometry.

A method of ultra-fast liquid chromatography in series with tandem mass spectrometry for the rapid and sensitive detection of 57 compounds in Spatholobi Caulis (the vine stem of Spatholobus suberectus Dunn) within 35 min was established. This assay can simultaneously determine a variety of compounds without matrix interference in multiple reaction monitoring mode including evaluating the quality of different batches of Spatholobi Caulis from several areas and further identifying the characteristic compounds efficiently. After comprehensive validation, this method can be used to determinate samples rapidly, precisely, accurately, repeatably, and sensitivity. There were significant content differences in 12 batches of Spatholobi Caulis, which were further classified and systematically differentiated applying multivariate statistical analysis. Furthermore, orthogonal partial least squares discrimination analysis results indicated that (-)-gallocatechin (10), (-)-epiafzelechin (20), 4,7,2'-trihydroxy-4'-methoxyisoflavanol (51), and biochanin A (53) characterize compounds to discernment internal quality of Spatholobi Caulis, and recommended as quality control indicators. Hence, presented work provides a method for further study on pharmaceutic preparation, metabolism, as well as for the design, production optimization process, and clinical application.

Comparative Metabolite Profiling of Wild and Cultivated Licorice Based on Ultra-Fast Liquid Chromatography Coupled with Triple Quadrupole-Time of Flight Tandem Mass Spectrometry.

Licorice is one of the ancient and most frequently applied herbs for its diverse phytochemicals. At present, wild resources of licorice have rapidly declined with increasing demand and the proportion of cultivated products in the market is quickly growing. However, the different level in chemical composition between the wild and cultivated licorice may result in the discrepancy in quality and pharmacological activity. Therefore, an ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry (UFLC-Triple TOF-MS/MS) method combined with multivariate statistical analysis technology was employed to explore chemical composition differences. The result showed that total 63 components were identified from licorice samples. The wild and the cultivated licorice are obviously classified into two groups according to principal component analysis (PCA). PCA and partial least squared discrimination analysis (PLS-DA) were also introduced to rapidly find 14 candidate compounds between two ecotypes of licorice. Apart from glycyrrhizin, licorice saponin J2/G2, glyasperin D and dehydroglyasperin D also could be selected as chemical markers based on t-test and variable importance in the projection (VIP) value. Our study successfully established an effective method for exploring metabolite profiling between two ecotypes of licorice and laying the foundation for distinguishing wild and cultivated licorice.

Qualitative and Quantitative Analysis of the Saponins in Panacis Japonici Rhizoma Using Ultra-Fast Liquid Chromatography Coupled with Triple Quadrupole-Time of Flight Tandem Mass Spectrometry and Ultra-Fast Liquid Chromatography Coupled with Triple Quadrupole-Linear Ion Trap Tandem Mass Spectrometry.

Panacis Japonici Rhizoma (PJR) contains various kinds of saponins, which possesses extensive pharmacological activities, but studies of comprehensive analysis of its saponins were limited. Thus, ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry (UFLC-Triple TOF-MS/MS) and ultra-fast liquid chromatography coupled with triple quadrupole-linear ion trap tandem mass spectrometry (UFLC-QTRAP-MS/MS) methods were established for the qualitative and quantitative analysis of the saponins in PJR, separately. Fifty three saponins in PJR were identified by UFLC-Triple TOF-MS/MS method, 23 saponins of which were unequivocally identified by reference substances. In addition, fragmentation pathways of different types of saponins were preliminarily deduced by fragmentation behavior of 53 saponins. Furthermore, the simultaneous determination of the contents of 13 saponins in PJR samples harvested at different times were analyzed by UFLC-QTRAP-MS/MS method. Furthermore, the quality of the samples was evaluated by grey relational analysis. This study might be beneficial to the quality assessment and control of PJR. Meanwhile, it might provide the basic information for confirming its optimal harvested period.

Chemical profiling of Banxia-Baizhu-Tianma decoction by ultra-fast liquid chromatography with tandem mass spectrometry.

Banxia-Baizhu-Tianma decoction (BBTD) is a compound formulae of traditional Chinese medicine (TCM), which has been clinically used for treatments of neural vertigo, hypertension and epilepsy with a long history. In this study, with an ultra-fast liquid chromatography coupled with quadrupole time of flight mass spectrometry (UFLC-Q-TOF-MS) method, a total of 88 components in BBTD were identified by the accurate masses and fragmentation pathways including 19 flavonoids, 8 lactones, 12 triterpenoids, 10 phenolics, 14 amino acids, 13 nucleobases and nucleosides, 7 organic acids, and 5 other compounds. In addition, under the same chromatographic conditions, we developed an ultra-fast liquid chromatography coupled with quadrupole linear ion trap mass spectrometry (UFLC-Q-TRAP-MS) method to simultaneously quantify 20 bioactive components in multiple-reaction monitoring (MRM) mode. The assay method was validated in terms of linearity, precision, repeatability, recovery and was successfully applied for determination of 12 batches of BBTD. We hope that this study work would help to reveal the chemical profiling and provide a valuable and reliable approach for quality evaluation and even efficacy material basis study of BBTD.

Simultaneous Characterization and Quantification of Varied Ingredients from Sojae semen praeparatum in Fermentation Using UFLC⁻TripleTOF MS.

Systematic comparison of active ingredients in Sojae semen praeparatum (SSP) during fermentation was performed using ultra-fast liquid chromatography (UFLC)-TripleTOF MS and principal component analysis (PCA). By using this strategy, a total of 25 varied compounds from various biosynthetic groups were assigned and relatively quantified in the positive or negative ion mode, including two oligosaccharides, twelve isoflavones, eight fatty acids, N-(3-Indolylacetyl)-dl-aspartic acid, methylarginine, and sorbitol. Additionally, as the representative constituents, six targeted isoflavones were sought in a targeted manner and accurately quantified using extracted ion chromatograms (XIC) manager (AB SCIEX, Los Angeles, CA, USA) combined with MultiQuant software (AB SCIEX, Los Angeles, CA, USA). During the fermentation process, the relative contents of oligoses decreased gradually, while the fatty acids increased. Furthermore, the accurate contents of isoflavone glycosides decreased, while aglycones increased and reached a maximum in eight days, which indicated that the ingredients converted obviously and regularly throughout the SSP fermentation. In combination with the morphological changes, which meet the requirements of China Pharmacopoeia, this work suggested that eight days is the optimal time for fermentation of SSP from the aspects of morphology and content.

Phenolic compounds from Viscum album tinctures enhanced antitumor activity in melanoma murine cancer cells.

Cancer is one of the biggest problems in public health worldwide. Plants have been shown important role in anticancer research. Viscum album L. (Santalaceae), commonly known as mistletoe, is a semi-parasitic plant that grows on different host trees. In complementary medicine, extracts from European mistletoe (Viscum album L.) have been used in the treatment of cancer. The study was conducted to identify chemical composition and antitumor potential of Viscum album tinctures. Chemical analysis performed by high resolution chromatography equipped with high resolution mass spectrometer identified caffeic acid, chlorogenic acid, sakuranetin, isosakuranetin, syringenin 4-O-glucoside, syringenin 4-O-apiosyl-glucoside, alangilignoside C and ligalbumoside A compounds. Some of these compounds are probably responsible for the reduction of tumoral cellular growth in a dose-dependent manner. It was observed that melanoma murine cells (B16F10) were more sensitive to V. album tinctures than human leukaemic cells (K562), besides non-tumoral cells (MA-104) had a much lower cytotoxicity to them. Apoptotic-like cells were observed under light microscopy and were confirmed by a typical DNA fragmentation pattern. Additionally, flow cytometry results using Annexin-V/FITC permitted to quantify increased expression of early and late apoptotic markers on tumoral cells, confirming augmented Sub G0 population, which was probably associated with a consistent decrease in G1, and an increase in S or G2/M populations. Results indicate the chemical composition of V. album tinctures influences the mechanisms of in vitro tumoral cell death, suggesting a potential use in cancer pharmacotherapy research.

Determination of the transformation of ginsenosides in Ginseng Radix et Rhizoma during decoction with water using ultra-fast liquid chromatography coupled with tandem mass spectrometry.

This study was conducted to determine the variations of ginsenosides in Ginseng Radix et Rhizoma when using different preparation solvents and explore the major factors for changes. With an established ultra-fast liquid chromatography coupled with tandem mass spectrometry method which could quantify 52 ginsenosides, the extraction differences were characterized and compared using different solvents (water, 70% aqueous ethanol, and ethanol). Subsequently, a series of aqueous solutions with different pH were prepared to test the influence of pH to the changes of ginsenosides. Meanwhile, acetic acid and aspartic acid were used to verify whether the reaction had a relationship with the kind of acids. After refluxing with water, not only highly polar ginsenosides were extracted, some less polar ginsenosides such as ginsenoside Rg3 , Rg5 , Rk1 , and Rh2 occurred or increased rapidly. Further experiments indicated that less polar ginsenosides were easier to generate at low pH values, and the reaction was only related to pH other than what kind of acids were used. It is the first time to elaborate the contents variation of 52 ginsenosides when using different extraction methods. The results indicated that decoction with water could enhance the transformation of highly polar ginsenosides to less polar ginsenosides and the process was pH dependent.

Fast liquid chromatography for racemic atenolol acetate separation-The analytical protocol.

Kinetic resolution of (R,S)-atenolol is a faster strategy to produce (S)-atenolol. Since this racemate is a less soluble compound, resolution of its ester offers high concentrations in the process. A good analytical method is required to observe the enantiomer concentrations. This paper described application of ultra-fast liquid chromatography on the atenolol ester separation using different resolution media and analytical procedures. Chiralcel OD column resolved the ester. The chromatograms indicated different characteristics of the process. The enantiomers could be recognized by the column in less than 1 (one) hour. Symmetrical peaks were obtained, but several procedures produced peaks with wide bases and slanted baselines. Efficient enantioresolution was obtained at high mobile phase flow rate, decreased concentration of amine-type modifier, but increased alcohol content in the mobile phase. High UV detection wavelength was required. At 1.0 mL/min, the (90/10/0.5) composition resulted α = 1.46 and RS  = 0.9998 that were good separation.

Physicochemical Characterization of Mitragyna speciosa Alkaloid Extract and Mitragynine using In Vitro High Throughput Assays.

AIM AND OBJECTIVE: Mitragynine, a major active alkaloid of Mitragyna speciosa, acts as an agonist on µ-opioid receptors, producing effects similar to morphine and other opioids. It has been traditionally utilized to alleviate opiate withdrawal symptoms. Besides consideration about potency and selectivity, a good drug must possess a suitable pharmacokinetic profile, with suitable absorption, distribution, metabolism, excretion and toxicity (ADME-Tox) profile, in order to have a high chance of success in clinical trials. MATERIAL AND METHOD: The purity of mitragynine in a Mitragyna speciosa alkaloid extract (MSAE) was determined using Ultra-Fast Liquid Chromatography (UFLC). In vitro high throughput ADMETox studies such as aqueous solubility, plasma protein binding, metabolic stability, permeability and cytotoxicity tests were carried out to analyze the physicochemical properties of MSAE and mitragynine. The UFLC quantification revealed that the purity of mitragynine in the MSAE was 40.9%. RESULTS: MSAE and mitragynine are highly soluble in aqueous solution at pH 4.0 but less soluble at pH 7.4. A parallel artificial membrane permeability assay demonstrated that it is extensively absorbed through the semi-permeable membrane at pH 7.4 but very poorly at pH 4.0. Both are relatively highly bound to plasma proteins (> 85 % bound) and are metabolically stable to liver microsomes (> 84 % remained unchanged). In comparison to MSAE, mitragynine showed higher cytotoxicity against WRL 68, HepG2 and Clone 9 hepatocytes after 72 h treatment. CONCLUSION: The obtained ADME and cytotoxicity data demonstrated that both MSAE and mitragynine have poor bioavailability and have the potential to be significantly cytotoxic.

Directly-coupled-column ultra-fast liquid chromatography with diode array detection method for the rapid quantification of allergenic disperse dyes in water preconcentrated by magnetic solid-phase extraction.

A directly-coupled-column ultra-fast liquid chromatography coupled with diode array detection method for the determination of 12 allergenic disperse dyes in river water at sub-ppb levels has been developed and successfully validated. The analytical method is based on the use of two different reversed-phased columns connected through a two-position switching valve. A baseline separation was achieved by proper selection of stationary phases, mobile phases, and the use of a gradient elution in both dimensions. Furthermore, an easy-to-handle magnetic solid-phase extraction procedure was developed for the preconcentration of 12 allergenic disperse dyes from river water. An enrichment factor of 100 times was obtained. The results showed excellent performance in terms of trueness (76.8-99.0%), precision (intraday: 2.2-8.0%, interday: 3.3-8.2%), and sensitivity (limits of determination, 0.027-1.46 µg/L). Twenty real samples collected from the outfalls in the Yaojiang, Yongjiang and Fenghuajiang estuary were analyzed, and three of the studied compounds were found in one collected sample (12.6 µg/L for disperse blue 7, 11.6 µg/L for disperse blue 106, and 0.22 µg/L for disperse blue 3).

Simultaneous determination of ferulic acid and gastrodin of Tianshu Capsule in rat plasma by ultra-fast liquid chromatography with tandem mass spectrometry and its application to a comparative pharmacokinetic study in normal and migraine rats.

Tianshu Capsule, consisting of Ligusticum chuanxiong Hort and Gastrodia elata Blume, is a widely used Traditional Chinese Medicine preparation for the treatment of migraine. Ferulic acid and gastrodin are main active constituents in Ligusticum chuanxiong Hort and Gastrodia elata Blume, and have been used as marker components for quality control of Tianshu Capsule. In this study, a selective, sensitive, and reliable ultra-fast liquid chromatography with tandem mass spectrometry method was developed for simultaneous determination of ferulic acid and gastrodin in rat plasma using geniposide as internal standard. The plasma samples were extracted by protein precipitation with methanol after acidification and separated on a Shim-Pack XR-ODS C18 column (75 × 3.0 mm, 2.2 µm) using gradient elution with a mobile phase consisting of water (containing 0.1% formic acid) and acetonitrile at a flow rate of 0.6 mL/min. Detection was performed on 3200 QTRAP mass spectrometry equipped with turbo ion spray source in negative ionization mode. Validation parameters were within acceptable ranges. The validated method was applied to compare the pharmacokinetic profiles of ferulic acid and gastrodin in normal and migraine rats. Our results showed that there were remarkable differences in the pharmacokinetic properties of the analytes between the normal and migraine groups.

Simultaneous determination of multiple active components in rat plasma using ultra-fast liquid chromatography with tandem mass spectrometry and application to a comparative pharmacokinetic study after oral administration of Suan-Zao-Ren decoction and Suan-Zao-Ren granule.

Suan-Zao-Ren decoction has been used to treat insomnia for many years. In this work, a rapid and sensitive ultra-fast liquid chromatography with tandem mass spectrometry method was first developed and fully validated for the simultaneous quantification of seven main active components, spinosin, mangiferin, neomangiferin, ferulic acid, liquiritin, isoliquiritin, and liquiritin apioside in rat plasma. The method was also successfully applied to compare the pharmacokinetics of these active ingredients after oral administration of Suan-Zao-Ren decoction and Suan-Zao-Ren granule. The separation was achieved on a Venusil MP C18 column and the detection was conducted by the multiple reaction monitoring mode using negative ion mode. Each calibration curve had good linearity over a wide concentration range. The precision of intra- and interday were all within 15%, and the extraction recoveries at different analyte concentrations were all above 82.0%. The established method was successfully applied to compare the pharmacokinetic profiles of the analytes between Suan-Zao-Ren decoction and Suan-Zao-Ren granule groups. The results indicated that all the analytes had similar mean concentration-time curves trend between two groups. No significant differences were observed in pharmacokinetic parameters of mangiferin, while the others had significant differences.

Ultra-fast liquid chromatography with tandem mass spectrometry determination of eight bioactive components of Kai-Xin-San in rat plasma and its application to a comparative pharmacokinetic study in normal and Alzheimer's disease rats.

A method of ultra-fast liquid chromatography with tandem mass spectrometry was developed and validated for the simultaneous quantitation of eight bioactive components, including polygalaxanthone III, sibiricaxanthone B, tenuifolin, sibiricose A5, sibiricose A6, tenuifoliside A, ginsenoside Re and ginsenoside Rb1 in rat plasma after oral administration of Kai-Xin-San. The plasma samples were extracted by liquid-liquid extraction using digoxin as an internal standard. Chromatographic separation was performed on a Venusil MP C18 column (100 mm × 2.1 mm, 3 µm) with methanol and 0.05% acetic acid in water as mobile phase. The tandem mass spectrometric detection was performed in the multiple reaction monitoring with turbo ion spray source in the negative ionization. Validation parameters were within acceptable ranges. The established method has been successfully applied to compare the pharmacokinetic profiles of the analytes between normal and Alzheimer's disease rats. The results indicated that there were significant differences in pharmacokinetic parameters of some components between two groups, which may be due to the mechanisms of Alzheimer's disease and pharmacological effects of the analytes. The pharmacokinetic research in the pathological state might provide more useful information to guide the clinical usage of herbal medicine.

Self-assembled magnetic nanoparticle supported zeolitic imidazolate framework-8: An efficient adsorbent for the enrichment of triazine herbicides from fruit, vegetables, and water.

Zeolitic imidazolate frameworks have positive surface charges and high adsorption capabilities. In this work, zeolitic imidazolate frameworks-8 and negatively charged magnetic nanoparticles were self-assembled by electrostatic attraction under sonication. The extraction performance of the synthesized hybrid material was evaluated by using it as a magnetic adsorbent for the enrichment of triazine herbicides in various sample matrices prior to analysis using ultrafast liquid chromatography. The main parameters, that is, extraction time, adsorbent dosage, salt concentration, and desorption conditions, were evaluated. Under the optimum conditions, good linear responses from 2.5 to 200 ng/mL for atrazine (simazine) and 1 to 200 ng/mL for prometryn (ametryn), with correlation coefficients (R2 ) higher than 0.9992 were obtained. The detection limits of the method (S/N = 3) were 0.18-0.72 ng/mL. The proposed method was successfully used to determine triazine herbicides in six samples, namely, apple, pear, strawberry, pakchoi, lettuce, and water. The amounts of simazine in all the fruit and vegetable samples were 10.8-25.2 ng/mL. The recoveries of all the analytes were 88.0-101.9%, with relative standard deviations of less than 8.8%.

Simultaneous determination and pharmacokinetic study of four phenolic acids in rat plasma using UFLC-MS/MS after intravenous administration of salvianolic acid for injection.

A simple, sensitive and selective ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method was established for simultaneous determination and pharmacokinetic study of rosmarinic acid (RA), salvianolic acid D (Sal D), lithospermic acid (LA) and salvianolic acid B (Sal B) in rat plasma after intravenous administration of salvianolic acid for injection (SAFI). Three doses of administration, containing 14, 28 and 56mg/kg, were investigated in this study. Plasma samples were pretreated using protein precipitation (PP) with pre-cooled acetonitrile. Chromatographic separation was achieved on a CORTECS™ UPLC C18 column (1.6µm, 2.1×100mm) with a mobile phase composed of 0.1% formic acid aqueous (V/V) and 0.1% formic acid acetonitrile (V/V). Analytes were detected using electrospray ionization (ESI) source in negative ionization mode and quantified in multiple reaction monitoring (MRM) mode. The validated method is stable and reliable. No significant difference of half lives (t1/2) of four analytes at three doses was observed. Area under the curve (AUC0-∞) and peak concentration (Cmax) of the four analytes demonstrated a linear increase in across the doses with the linear correlation r of each analyte at three doses were greater than 0.95. It indicated that the pharmacokinetic behavior of SAFI is positively related to dose at the range of 14-56mg/kg.