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Isocorynoxeine is one of the main alkaloids in Chinese medicinal herbs, and has pharmacological activities such as antihypertensive, sedative, anticonvulsant, and neuronal protection. It is an effective component of Uncaria for the treatment of hypertension. In this study, we used a fast and sensitive ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) to detect isocorynoxeine in rat plasma and investigated its pharmacokinetics in rats. Six rats were given isocorynoxeine (15 mg/kg) by intraperitoneal (i.p.) administration. Blood (100 μL) was withdrawn from the caudal vein at 5 and 30 min and 1, 2, 4, 6, 8, 12, and 24 h after administration. Chromatographic separation was achieved using a UPLC BEH C18 column using a mobile phase of acetonitrile–0.1% formic acid with gradient elution. Electrospray ionization (ESI) tandem mass spectrometry in the multiple reaction monitoring (MRM) mode with positive ionization was applied. Intra-day and inter-day precisions (relative standard deviation, %RSD) of isocorynoxeine in rat plasma were lower than 12%. The method was successfully applied in the pharmacokinetics of isocorynoxeine in rats after intraperitoneal administration. The t 1/2 of isocorynoxeine is 4.9 ± 2.1 h, which indicates quick elimination.

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Berendsen, B.J.A., Essers, M.L., Stolker, A.A.M. & Nielen, M.W.F. (2011): Quantitative trace analysis of eight chloramphenicol isomers in urine by chiral liquid chromatography coupled to tandem mass spectrometry. J. Chromatogr. A ., 1218 , 7331

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JPC - Journal of Planar Chromatography - Modern TLC
Authors: Emil Mincsovics, Péter Ott, Ágnes Alberti, Andrea Böszörményi, Éva Héthelyi, Éva Szőke, Ágnes Kéry, Éva Lemberkovics, and Ágnes Móricz

Bioassay-guided isolation of antibacterial components of chamomile flower methanol extract was performed by overpressured layer chromatography (OPLC) with on-line detection, fractionation combined with sample clean-up in-situ in the adsorbent bed after off-line sample application. The antibacterial effect of the eluted fractions and of those compounds remaining on the adsorbent layer after separation was tested with direct bioautography (DB) against the bioluminescent Pseudomonas savastanoi pv. maculicola and Vibrio fischeri. The fractions with high biological activity were analyzed by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) and liquid chromatography and tandem mass spectrometry (LC-MS/MS). Two active uneluted compounds were characterized by off-line OPLC-MS using a thin-layer chromatography (TLC)-MS interface. Mainly, essential oil components, coumarins, flavonoids, phenolic acids, and fatty acids were identified in the active fractions.

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Summary

A new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous determination of glycyrrhizin, formononetin, glycyrrhetinic acid, liquiritin, isoliquiritigenin, and licochalcone A in licorice. An Eclipse Plus C18 column (I.D. 4.6 × 100 mm, 3.5 μm particle size; Agilent) was used in the analysis. Electrospray ionization (ESI)-tandem interface in the negative mode was performed, and multiple reaction monitoring (MRM) was employed with the precursor multiple reaction monitoring production combination for the determination of six analytes. The average recoveries ranged from 98.30% to 100.13% with relative standard deviations (RSDs) ≤ 1.95%, and limits of detection (LODs) ranged from 2.1 to 3.6 pg. The applicability of this analytical approach was confirmed by the successful analysis of six samples. The results indicated that the established method was validated, sensitive, and reliable for the determination of six analytes in licorice.

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Acta Chromatographica
Authors: Gobinda Chandra Acharya, Naresh Ponnam, Meenu Kumari, Tapas Kumar Roy, Kodthalu Seetharamaiah Shivashankara, and Manas Ranjan Sahoo

Abstract

Spiny coriander (Eryngium foetidum L.) is a perennial medicinal herb grown in the tropical regions worldwide. In India, it is used as a potential spice for garnishing and flavoring the dishes and treating several ailments. Eryngium spp. found in coastal Odisha, India has a strong aroma similar to the seasonal Coriandrum. The volatile flavor constituents of the unique plants were analyzed through headspace solid-phase microextraction (HS-SPME) using capillary gas chromatography (GC) and gas chromatography-tandem mass spectrometry (GC–MS/MS). The volatile compounds exhibited high chemodiversity, with 10-undecenal as the major component in leaves (44.98%) and branches (57.43%). Fourier-transform infrared (FTIR) spectroscopy identified eight major peaks grouped into six main regions. Chemo profiles of these two corianders were overlapped and showed similar area differences in the spectral peak. The lesser-known perennial Eryngium with high chemodiversity would be a better alternative to the seasonal coriander for aromatic, pharmaceutical, and industrial uses.

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A comparative proteomic analysis of grain proteins during five grain developmental stages of wheat cultivar Chinese Spring (CS) and its 1Sl/1B substitution line CS-1Sl(1B) was carried out in the current study. A total of 78 differentially expressed protein (DEP) spots with at least 2-fold expression difference were detected by two-dimensional electrophoresis (2-DE). Among these, 73 protein spots representing 55 differentially expressed proteins (DEPs) were successfully identified by matrix-assisted laser desorption/ionization time-offlight tandem mass spectrometry (MALDI-TOF/TOF-MS). Differential protein spots between the two genotypes were analyzed by cluster software, which revealed significant proteome differences. There were 39 common spots (including 33 DEPs) that showed significant difference between the two lines across five grain developmental stages, of which 14 DEP spots (including 11 DEPs) were mainly involved in carbohydrate metabolism that were encoded by the genes on 1B chromosome while 25 DEP spots (including 12 DEPs) were mainly related to stress response and gluten quality that were encoded by 1S1 chromosome. These results indicated that the Sl genome harbors more stress and quality related genes that are potential valuable for improving wheat stress resistance and product quality.

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Seed germination is a new beginning for the crop life cycle, which is closely related to seed sprouting and subsequent plant growth and development, and ultimately affects grain yield and quality. Salt stress is one of the most important abiotic stress factors that restrict crop production. Therefore, it is highly important to improve crop salt tolerance and sufficient utilization of saline-alkali land. In this study, we identified the phosphorylated proteins involved in salt stress response by combining SEM, 2-DE, Pro-Q Diamond staining and tandem mass spectrometry. The results showed that salt stress significantly inhibited seed germination and starch degradation. In total, 14 phosphorylated protein spots (11 unique proteins) in the embryo and 6 phosphorylated protein spots (4 unique proteins) in the endosperm were identified, which mainly involved in stress/defense, protein metabolism and energy metabolism. The phosphorylation of some proteins such as cold regulated proteins, 27K protein, EF-1β and superoxide dismutase could play important roles in salt stress tolerance.

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The aim of this study was to assess the impact of hanging position of hunted pheasant carcasses (secured by the head as compared to hanging position secured by the legs) on the biogenic amine concentration in the thigh and breast muscles. The carcasses of feathered game (Phasianus colchicus), left entirely untreated after hunting and placed in a storage space at a pre-set temperature of 7 °C for 21 days were used in the study. Samples of breast and thigh muscles were taken at regular weekly intervals. Measurement of biogenic amines (putrescine, cadaverine, tyramine, tryptamine, histamine, phenylethylamine) was based on high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry. Higher biogenic amine concentrations were detected in the muscles (both breast and thigh) of pheasants hanging by their legs compared to pheasants hanging by their heads (no statistically significant difference in biogenic amine concentration between monitored groups was, however, established). Higher concentrations of biogenic amines were found in the thigh muscles compared to breast muscles in both monitored groups. The obtained results show, that hanging the carcasses of pheasants during storage by the head is more suitable method in term of biogenic amine concentration than storing carcasses hanging by the legs.

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Abstract

Chronic hepatitis B virus (HBV) carriers may develop hepatocellular carcinoma (HCC) by a wide range of mechanisms including angiogenesis. We show that HBV replication induces the expression of angiogenic proteins interleukin 6 (IL6) and cyclooxygenase-2 (Cox2). Interestingly, ibuprofen (a Cox2 inhibitor) is found to attenuate the levels of IL6 and Cox 2 which are induced by HBV replication.

The mechanism of attenuation of angiogenic proteins by ibuprofen was further investigated. Our results show that HBx is involved in the increase of the expression of Cox2 through the NFκB pathway. However, the expression of Cox2 is decreased when the HBx-expressing cells are incubated with ibuprofen. The contrasting effect of HBx on Cox2 is found to be determined by differential dimer formation among the members of the NFκB family of proteins, including NFκB, RelA, and C-rel. Specifically, HBx alone results in dimer formation between NFκB and RelA, while the combined presence of HBx and ibuprofen leads to the formation of NFκB and C-rel. Additional information on the interaction network involving HBx, ibuprofen, and NFκB pathways is revealed by two-dimensional liquid chromatography-tandem mass spectrometry proteomics analysis. Taken together, our findings provide new insights on the angiogenesis induced by HBV replication.

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In the present study, the degradation behavior of Fenofibrate under different International Conference on Harmonization (ICH) suggested conditions was studied. Characterization of degradation products by liquid chromatography–tandem mass spectrometry (LC–MS/MS) studies in solution form was done, and the possible mechanism for the formation of degradants is discussed. Fenofibrate was subjected to different hydrolytic stress conditions and thermal stress condition (in solid form). Successful separation of drug from degradants was achieved on a C18 column using water–acetonitrile (25:75 v/v) as the mobile phase. Other high-performance liquid chromatography (HPLC) parameters were: flow rate, 1 mL min−1; detection wavelength, 286 nm; column temperature, 25 °C; and injection volume, 20 μL. The method was validated for linearity, precision, accuracy, robustness, and specificity and was stability-indicating one, based on the specificity studies. The drug degraded under acidic, basic, and oxidative hydrolytic stress while it was relatively stable towards neutral hydrolysis and thermal stress. The stressed samples were subjected to LC–MS/MS analysis. On the basis of spectral data, the structures of four degradation products and one interaction product were suggested. Degradation products were characterized to be isopropyl acetate, 2-[4-(4-chlorobenzoyl)phenoxy]-2-methyl propanoic acid, 4-hydroxy benzoic acid, and benzoic acid. The structure of one interaction product was proposed as methyl 2-[4-(4-chlorobenzoyl)phenoxy]-2-methylpropanoate.

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