查看更多>>摘要：An in vitro intestinal absorption model combined with high-performance liquid chromatography-photo diode array-tandem mass spectrometry (HPLC-PDA-MS) was used for preliminary screening of potential active ingredients from complex multi-component traditional Chinese medicine (TCM) system. Oral administration is one of the main administration methods for TCMs. Only the ingredients that could be absorbed have the opportunity to play a role. Thus, these were defined as potential active ingredients. Studying of intestinal absorption can provide a theoretical basis for the mechanism of TCMs. The Caco-2 cell model, the everted rat gut sac model, and the Ussing chamber model were established for TCMs. The degree of anastomosis between the in vitro intestinal model and the actual intestinal absorption of TCMs were evaluated by the gavage method in rats. The Ussing chamber model was best fit for oral experiments in rats and was selected as the research means to preliminarily screen potential active ingredients from eight TCMs, including Salvia miltiorrhiza Bunge, Astragalus propinquus Schischkin, Plantago asiatica L, Fallopia multiflora (Thunb.) Harald, Epimedium brevicornu Maxim, Moutan Cortex, Citrus reticulata Blanco, and Panax notoginseng (Burkill) F. H. Chen ex C. H. Chow. A total of 44 components were absorbed and screened as the potential active ingredients from the 80 components identified in eight TCMs by HPLC-PDA-MS.
查看更多>>摘要：Favipiravir is a promising antiviral agent that has been recently approved for treatment of COVID-19 infection. In this study, a menthol-assisted homogenous liquid-liquid microextraction method has been developed for favi-piravir determination in human plasma using HPLC/UV. The different factors that could affect the extraction efficiency were studied, including extractant type, extractant volume, menthol amount and vortex time. The optimum extraction efficiency was achieved using 300 mu L of tetrahydrofuran, 30 mg of menthol and vortexing for 1 min before centrifuging the sample for 5 min at 3467g. Addition of menthol does not only induce phase separation, but also helps to form reverse micelles to facilitate extraction. The highly polar favipiravir molecules would be incorporated into the hydrophilic core of the formed reverse micelle to be extracted by the non-polar organic extractant. The method was validated according to the FDA bioanalytical method guidelines. The developed method was found linear in the concentration range of 0.1 to 100 mu g/mL with a coefficient of determination of 0.9992. The method accuracy and precision were studied by calculating the recovery (%) and the relative standard deviation (%), respectively. The recovery (%) was in the range of 97.1-103.9%, while the RSD (%) values ranged between 2.03 and 8.15 %. The developed method was successfully applied in a bio-equivalence study of Flupirava (R) 200 mg versus Avigan (R) 200 mg, after a single oral dose of favipiravir administered to healthy adult volunteers. The proposed method was simple, cheap, more eco-friendly and suf-ficiently sensitive for biomedical application.
查看更多>>摘要：The aluminum salt of fosetyl (tris(ethyl phosphonate)) is an antifungal agrochemical. This paper presents a novel high performance liquid chromatography (HPLC) method for the simultaneous determination of fosetyl and the phosphonic acid, its main metabolite, in food samples. The method is based on an ion-displacement separation performed on the recently released Luna Omega PS C18 mixed-mode HPLC column. Baseline separation of fosetyl and phosphonic acid was feasible. This was achieved by optimizing the mobile phase composition and by introducing ethylenediaminetetraacetate for all matrices in the generally used extraction medium for polar pesticides and the injection solution. The binary mobile phase consisted of 10% (v/v) methanol in water and aqueous formate buffer (pH = 3.5) in gradient elution mode. The main advantages of the method over previous method include the stable retention time and peak resolution without the need for long column priming, conditioning or regeneration. Moreover, the approach was tested with other polar pesticides including glyphosate, glufosinate, and perchlorate and showed fit-for-purpose separation. The method was validated for spinach, cherry, and wheat flour samples, and was successfully applied on oat flour and arugula quality control samples. The results obtained for the five analytes met the requirements set by EU. The limit of quantifications was much lower than the maximum residue limits and ranged from 0.02 to 0.20 mg/kg.
查看更多>>摘要：Dammar-20(22)E,24-Diene-3 beta,6 alpha,12 beta-Triol (YNPT2), as one of the main pharmacological and active components of Panax ginseng, promotes ubiquitination and degradation of hypoxia inducible factor Ia through proteasome, which reduces the content of hypoxia inducible factor Ia in tumor cells. Therefore, it is widely used in tumor inhibition. A sensitive and specific bioanalytical method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the quantification of YNPT2 rat plasma has been developed. Buspirone was used as the internal standard (IS). A 50 mu l aliquot of rat plasma sample was deproteinized by 150 mu l methanol-acetonitrile (1:1,v:v), vortex-mixed for 1 min and centrifuged at 15,000 r/min for 10 min at 4 degrees C. Then, 120 mu l of supernatant was pipetted out into the autosampler vials and analyzed by LC-MS/MS with 10 mu l injection volume. Chromatographic separation was performed on an Agilent ZORBAX XDB-C18 column (2.1 x 50 mm, 3.5 gm) with mobile phases consisting of water containing 5 mM ammonium acetate (mobile phase A) and acetonitrile (mobile phase B) at a flow rate of 0.6 ml/min over a total run time of 4.0 min. YNPT2 and buspirone (IS) were detected and quantified using positive electrospray ionization in multiple reaction monitoring (MRM) mode with transitions of m/z 441.4 -> 109.1 for YNPT2 and m/z 386.3 -> 122.1 for IS. The linear range was 5-2000 ng/ml with the square regression coefficient (r(2)) of 0.9972, and the lower limit of quantification (LLOQ) was 5 ng/ml. The intra-day and inter-day precision deviations of YNPT2 ranged from 3.8 to 6.9% and 3.5-5.8%, and accuracy error ranged from -7.4-5.9% and -9.2-11.9%. The average extraction recovery of YNPT2 in rat plasma was between the range of 98.5%-102.7%. This method was successfully applied to study the pharmacokinetics of YNPT2 in rats after intragastric administration at a single dose of 10.0 mg/kg and after intravenous injection at a single dose of 2.0 mg/kg.
查看更多>>摘要：The hallmarks of cancer include metabolism with deregulating cellular energetics. Dysfunctions in succinate dehydrogenase (SDH) metabolic enzyme activity, leading to an abnormal accumulation of succinic acid has been described in solid tumors but also in inflammation and ischemia reperfusion injury. Succinic acid is a potential biomarker of SDH related pathologies for diagnostic, evaluation of treatment response and follow-up of the disease. We developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) method allowing a rapid, accurate and precise quantification of succinic acid levels in clinical (serum, urine) and preclinical (cellular pellets, supernatants) samples. C-13(4) succinic acid disodium salt was used as internal standard and added to samples before a solid phase extraction (SPE) on Phenomenex STRATA (TM) XL-A (200 mg - 3 mL) 33 mu m cartridges. This method is automated by a Freedom EVO (R) platform from TECAN and succinic acid is separated on a C18 column combined to a Xevo (R) TQ-S micro Waters mass spectrometer with electrospray ionization (ESI) source. This biomedical analysis allows standard curves to be linear over the range 1.0-135.5 mu M with r(2) values > 0.999 and low matrix effects (<9.1 %). This method, which is validated according updated European Medicine Agency (EMA) guidelines, is accurate between-run (<11.0 %) and within-run (<7.8 %), precise between-run (<14.4 CV %) and within-run (<3.7 CV %), and is suitable for clinical and preclinical applications.
查看更多>>摘要：Emerging evidence has suggested that bexarotene, a nearly 20-year-old skin cancer drug, may be a potential drug candidate to treat Alzheimer's disease (AD) and other neurodegenerative disorders. As described in this study, a highly sensitive and rapid method, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine bexarotene in mouse plasma and brain tissue, was established and validated for the first time. Single-step protein precipitation utilizing methanol solution (containing 0.05 % acetic acid) as precipitation agent was employed to prepare the samples of plasma and brain tissue. Chromatographic separation in gradient elution mode was conducted via an Agilent ZORBAX SB-C18 column (50 mm x 4.6 mm, 5 mu m) employing methanol-ammonium acetate buffer (5 mM, pH adjusted to 4.6 with acetic acid) as mobile phase which flowed at 0.45 mL/min. The total run time was 6 min for each sample. Detection through mass spectrometric technique was operated by selected reaction monitoring (SRM) in negative electrospray ionization mode. The method was linear within the range of 10.0-15000 ng/mL for plasma and 10.0-600 ng/mL for brain tissue homogenate with the lower limit of quantification of 10.0 ng/ml. The plasma or tissue homogenate was only required 20 mu L. The intra-and inter-day precision were less than 13.8 %, and the RE was between -7.4 % and 3.4 %. The method was applied to investigate the plasma pharmacokinetics and brain distribution of bexarotene in mice after being intragastrically administered with bexarotene at the dosage of 100 mg/kg. The results showed that both brain and plasma concentrations of bexarotene peaked at 1.0 h. Bexarotene was rapidly eliminated with a half-life of 2.0 h.
查看更多>>摘要：Considering the importance of glycopeptides in the clinical diagnosis of cancer and some serious diseases, the identification of glycopeptides from complex biological samples has attracted considerable attention. Effective pre-enrichment before mass spectrometry analysis plays an important role. In this work, a kind of hydrophilic two-dimensional composites (denoted as GO@MPDA@Arg) based on mesoporous polydopamine-graphene oxide were used to selectively enrich glycopeptides in biological samples. The mesoporous polydopamine (MPDA) layer self-assembled with template Pluronic F127 provided more binding sites to load arginine, and bound arginine enhanced the hydrophilicity of the material. As a result, GO@MPDA@Arg composites exhibited excellent enrichment performance for glycopeptides, containing good selectivity (IgG digests : BSA digests = 1:50, molar ratio), low detection limit for IgG digests (10 fmol mu L-1), high loading capacity for IgG digests (200 mu g mg(-1)), and good size exclusion (IgG digests : IgG : BSA = 1:100:100, mass ratio). In addition, mouse brain tissue was selected as the actual biological sample to further study the enrichment effect of GO@MPDA@Arg composites. In three parallel experiments, a total of 401 glycopeptides belonging to 233 glycoproteins were enriched from 200 mu g digestion of mouse brain extract. The enrichment results demonstrate that GO@MPDA@Arg composites have application potential for glycopeptides enrichment in protein post-translational modification research.
Donkor, Abigail B. B.White, Carl W. W.Nick, Heidi J. J.Logue, Brian A. A....
7页
查看更多>>摘要：Sodium 2-mercaptoethane sulfonate (MESNA) is a thiol-containing compound that has proven to be effective in inactivating acrolein, the toxic metabolite of some anti-cancer drugs (e.g., cyclophosphamide and ifosphamide). Also, it scavenges free radicals which cause numerous disorders by attacking biological molecules. Current methods available to analyze MESNA in biological matrices include colorimetry and high-performance liquid chromatography (HPLC) with ultraviolet, fluorescence, or electrochemical detection. These methods have several limitations including low sensitivity, poor selectivity, a high degree of difficulty, and long analysis times. Hence, a rapid, simple, and sensitive HPLC tandem mass spectrometry (MS/MS) method was developed and validated to quantify MESNA in rat plasma following IP administration. The analysis of MESNA was accomplished via plasma protein precipitation, centrifugation, supernatant evaporation, reconstitution, and HPLC-MS/MS analysis. The method showcases an outstanding limit of detection (20 nM), excellent linearity (R-2 = 0.999, and percent re-sidual accuracy > 90%) and a wide linear range (0.05-200 mu M). The method also produced good accuracy and precision (100 +/- 10% and < 10% relative standard deviation, respectively). The validated method was suc-cessfully used to analyze MESNA from treated animals and will allow easier development of MESNA for ther-apeutic purposes.
查看更多>>摘要：Methionine is a common excipient used in therapeutic protein liquid formulations as stabilizer and antioxidant. The oxidation of methionine to methionine sulfoxide can be regarded as a sensitive marker of oxidative stress for drug product storage conditions. In this study, a sensitive HPLC method for the quantification of methionine sulfoxide in formulated protein product was developed and qualified according to regulatory requirements using a SIELC (R) Primesep 100 column with UV detection. The separation involves a mixed-mode mechanism including reversed phase and cationic exchange modalities. The operating range of the method was established between 1 mu M and 35 mu M of methionine sulfoxide. In this testing range, the method was shown to be linear (R-2 > 0.99), accurate (Recovery 92.9 - 103.6%, average recovery = 99.8 +/- 1.4%) and precise (intermediate precision at LoQ, CV = 2.9%). The developed test system was successfully applied to study the effects of temperature and storage conditions on methionine sulfoxide formation in complex therapeutic antibody formulations.
NSTL
Elsevier