Ecdysteroids represent a large class of polyhydroxylated steroids which, due to their anabolic properties, are marketed as dietary supplements. Some ecdysteroids also act as important hormones in arthropods, where they regulate molting, development, and reproduction and many of these insects are miniature organisms that contain submicroliter levels of circulating biofluids. Analysis of ecdysteroids is further complicated by their very low abundance, large fluctuations during development, and difficult access to a pooled sample, which is important for quantitative measurements. In this work, we propose a new method that overcomes the described difficulties and allows validated quantification of four ecdysteroids in minimal amounts of biological material. After methanolic extraction, detectability of the ecdysteroids is increased 16- to 20-fold by conversion to their 14,15-anhydrooximes. These are further purified by pipette tip solid-phase extraction on a three-layer sorbent and subjected to HPLC-MS/MS analysis. Full validation was achieved using hemolymph from larvae of the firebug Pyrrhocoris apterus as a blank matrix and by the determination of ecdysteroids in a single Drosophila larva. The lower limit of quantifications for the four target ecdysteroids (20-hydroxyecdysone, ecdysone, makisterone A, and 2-deoxyecdysone) were 0.01; 0.1; 0.05; and 0.025 pg·ml-1 (20; 200; 100; 50 fmol ml-1), respectively, with very good accuracy, precision (expressed as relative standard deviation <15%) and recoveries (96%-119.9%). The application potential of the new method was demonstrated by quantification of ecdysteroids in various biological materials including human serum.

• Klíčová slova
• arthropods, dietary supplementation, ecdysteroid hormones, human body fluid, quantification, submilligram sample amount, ultratrace HPLC-MS analysis,
• MeSH
• ekdysteroidy * analýza   krev   chemie   MeSH
• hemolymfa chemie   metabolismus   MeSH
• kapalinová chromatografie-hmotnostní spektrometrie MeSH
• larva MeSH
• tandemová hmotnostní spektrometrie * metody   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• validační studie MeSH
• Názvy látek
• ekdysteroidy * MeSH

Two mass spectrometric methods for analysing triacylglycerols (HPLC/APCI-MS and MALDI-MS) were used and compared in terms of the relevance of the data for further biostatistical evaluation. While MALDI-MS is simpler and significantly faster, the time-consuming and labour-intensive HPLC/APCI-MS provides more complete information about the lipid components. However, both methods provide well-comparable results concerning the grouping of specimens belonging to different species when evaluated with multivariate exploratory approaches. The compositions of triacylglycerols in the fat bodies of males in 11 bumblebee species (Bombus terrestris, B. lucorum, B. lapidarius, B. pratorum, B. sylvarum, B. ruderatus, B. pomorum, B. subterraneus, B. campestris, B. bohemicus, and B. rupestris) were found to be species-specific.

• MeSH
• druhová specificita MeSH
• hmotnostní spektrometrie metody   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• triglyceridy chemie   MeSH
• tukové těleso chemie   MeSH
• včely chemie   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• triglyceridy MeSH

INTRODUCTION: Helichrysum leucocephalum Boiss. (Asteraceae) is an endemic plant to Iran. No reports have studied the cytotoxicity of the plant. The current study aimed to evaluate the cytotoxicity of H. leucocephalum collected from Fars province (Iran) against MCF-7 and HDF cell lines using HPLC-based activity profiling and to annotate the active constituents by LC-ESIQTOF-MS/MS. METHODS: H. leucocephalum was collected from three locations in Fars province. The dried flowers and leaves were separately extracted by percolation using methanol. The crude extracts were fractionated by liquid-liquid partitioning with dichloromethane (DCM) and aqueous methanol. The cytotoxicity of the fractions was evaluated against MCF-7 and HDF cells by Alamarblue assay. HPLC-based activity profiling was used to track the active constituents. LC-MS dereplication strategy was used for the annotation of the compounds in the active time window. LC-MS data were preprocessed by MZmine 3.3.0 and submitted to multivariate analysis to compare the differences and similarities in the metabolites of the samples. RESULTS: The DCM fractions showed a dose-dependent cytotoxicity against the cancerous cells (IC50s, 9.8-105.1 μg/ml). In general, the metabolites of the flowers and their cytotoxicity were higher than the leaves. LCESIMS/MS analyses revealed that prenylated and geranylated α,β-unsaturated spiroketal phloroglucinols were among the active constituents. CONCLUSION: It can be concluded that H. leucocephalum is a rich source of phloroglucinol derivatives with cytotoxic activities. Further phytochemical analysis is needed to characterize the bioactive components.

• Klíčová slova
• Asteraceae, Cytotoxicity, HPLC, Helichrysum leucocephalum, LC-ESIQTOF-MS/MS,
• Publikační typ
• časopisecké články MeSH

Plants from the genus Astragalus are gaining attention for their pharmacological importance. However, the information available regarding the HPLC-MS/MS chemical profile of A. fruticosus is inadequate. In this study, we performed HPLC-MS/MS analysis using electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). We tentatively identified 11 compounds in the A. fruticosus methanolic extract, including five flavonoidal and six saponin glycosides. The extract showed moderate antioxidant activity with 21.05% reduction in DPPH UV absorption. The preliminary cytotoxic screening against seven human cancer cell lines using 100 μg/mL extract showed prominent cytotoxic potential against colorectal cancer HCT-116 with 3.368% cell viability. It also showed moderate cytotoxic potential against prostate (DU-145), ovarian (SKOV-3) and lung (A-549) cancer cell lines with cell viability of 14.25%, 16.02% and 27.24%, respectively. The IC50 of the total extract against HCT-116 and DU-145 cell lines were 7.81 μg/mL and 40.79 μg/mL, respectively. The observed cytotoxicity of the total methanolic extract from the leaves against colorectal cancer might facilitate future investigations on cytotoxic agent(s) for disease management.

• Klíčová slova
• Astragalus fruticosus, HPLC–MS/MS profiling, colorectal cancer, cytotoxic activity,
• Publikační typ
• časopisecké články MeSH

A simple, sensitive HPLC-MS/MS method was developed and validated for the determination of lidocaine in skin and plasma of rats. The methods were established and validated assessing lower limit of quantitation (LLOQ), linearity, intra and inter-day precision and accuracy, selectivity, recovery and matrix effect. Chromatography was done on a Gemini column embedded with C18 stationary phase (50 mm × 2.0 mm, 5 µm particle size), using a gradient with mobile phases consisting of 0.1% HCOOH in bidistilled water and 0.1% HCOOH in acetonitrile. The mass spectrometer worked with electrospray ionization in positive ion mode and selected reaction monitoring, using target ions m/z 235.10 for lidocaine and m/z 245.10 for lidocaine-d10, used as internal standard. RESULTS: The linearity of the method was in the ranges of lidocaine concentrations 10.0-200.0 ng/mL for skin homogenate (accuracy 94.1-105.5%; R2 ≥ 0.998) and 0.025-2 ng/mL for plasma (accuracy 96.2-104.8%; R2 ≥ 0.996). The intra- and inter-day precision and accuracy determined on three quality control samples (20, 75 and 170 ng/mL for skin and 0.075, 0.4 and 1.5 ng/mL for plasma) were ≤4.2% and 103.8-108.2% for skin and ≤12.4% and 95.5-101.4% for plasma. The LLOQ was 10 ng/mL in skin homogenate and 0.025 ng/mL in plasma. The applicability of the method was demonstrated by measuring lidocaine in skin and plasma after exposure to medicated patches containing 5% lidocaine.

• Klíčová slova
• HPLC-MS/MS analysis, Lidocaine, Medicated plaster, Pharmacokinetics, Skin,
• MeSH
• krysa rodu Rattus MeSH
• kůže chemie   MeSH
• lidokain aplikace a dávkování   analýza   farmakokinetika   MeSH
• limita detekce MeSH
• lineární modely MeSH
• reprodukovatelnost výsledků MeSH
• stabilita léku MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• transdermální náplast * MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• lidokain MeSH

ELISA is widely used for urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) analysis. It is the method of choice for laboratories that lack specialized chromatographic instrumentation. It allows fast, high-throughput sample analysis without a need for extensive samples processing. However, a lack of agreement between ELISA and chromatographic methods confines its application to the assessment of relative urinary 8-oxodG levels. We investigated various ELISA modifications, seeking optimal conditions that would yield a good agreement between ELISA and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS /MS). Purification of urine by solid phase extraction (SPE), then incubation with the anti-8-oxodG antibody at 4 °C overnight and subsequent normalization of 8-oxodG levels per urinary creatinine resulted in a near-perfect correlation and agreement in mean levels between ELISA and HPLC-MS /MS (r=0.917, p<0.001; and paired t-test p=0.803, respectively). Our data show that, after introduction of a simple modification, ELISA quantification urinary 8-oxodG substantially improves. Although more sample manipulation is required, the method retains its key advantages over chromatography (high-throughput analysis that does not require expensive instrumentation). This represents a significant advance for the ELISA, and encouraging its use in more studies adding to our knowledge of the role of this biomarker of oxidative stress in health and disease.

• Klíčová slova
• 8-OxodG, Discrepancy, ELISA, HPLC–MS /MS, Oxidative stress, Urine,
• MeSH
• 8-hydroxy-2'-deoxyguanosin MeSH
• biologické markery moč   MeSH
• deoxyguanosin analogy a deriváty   moč   MeSH
• dospělí MeSH
• ELISA normy   MeSH
• extrakce na pevné fázi MeSH
• lidé středního věku MeSH
• lidé MeSH
• oxidační stres MeSH
• senzitivita a specificita MeSH
• tandemová hmotnostní spektrometrie normy   MeSH
• vysokoúčinná kapalinová chromatografie normy   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 8-hydroxy-2'-deoxyguanosin MeSH
• biologické markery MeSH
• deoxyguanosin MeSH

Nucleotides, nucleosides and their derivatives are present in all cells at varying concentrations that change with the nutritional, and energetic status of the cell. Precise measurement of the concentrations of these molecules is instrumental for understanding their regulatory effects. Such measurement is challenging due to the inherent instability of these molecules and, despite many decades of research, the reported values differ widely. Here, we present a comprehensive and easy-to-use approach for determination of the intracellular concentrations of >25 target molecular species. The approach uses rapid filtration and cold acidic extraction followed by high performance liquid chromatography (HPLC) in the hydrophilic interaction liquid chromatography (HILIC) mode using zwitterionic columns coupled with UV and MS detectors. The method reliably detects and quantifies all the analytes expected to be observed in the bacterial cell and paves the way for future studies correlating their concentrations with biological effects.

• Klíčová slova
• Escherichia coli, HILIC, HPLC-MS, Nucleotide, Stringent response, ppGpp,
• MeSH
• Escherichia coli K12 izolace a purifikace   MeSH
• hmotnostní spektrometrie metody   MeSH
• koncentrace vodíkových iontů MeSH
• limita detekce MeSH
• nukleotidy chemie   MeSH
• rozpouštědla chemie   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• nukleotidy MeSH
• rozpouštědla MeSH

The presented work proposes a novel analytical ICP-MS-based approach for the accurate and precise chromium speciation in biological tissues. The determination of total Cr(VI) and soluble Cr(III) species was carried out by alkaline EDTA extraction followed by their separation using ion-exchange high-performance liquid chromatography inductively coupled plasma mass spectrometry (IE-HPLC-ICP-MS). The developed method was validated according to the procedure given in the United States Food and Drug Administration guideline on the validation of bioanalytical methods. Validation parameters included limit of detection (≤ 0.03 μg g-1), limit of quantification (≤ 0.08 μg g-1), linearity (r ≥ 0.9998), intra-day and inter-day accuracy (86-110%) and precision (≤ 10%), extraction recovery (89-110%), carry-over effect and sensitivity. In addition, special attention was paid to the study of chromium species interconversion and the elimination of spectral interferences. Moreover, the validated ICP-MS method employing microwave acid digestion was used to determine the total Cr content in collected fractions. Finally, the whole ICP-MS-based methodology was applied to the analyses of two certified reference materials of hepatopancreas tissue. Obtained results indicated that the majority of chromium in biological tissues is bound to the solid residue, Cr(VI) was determined in none of the samples investigated. This is the first study focusing on soluble Cr(III), total Cr(VI), and total bound Cr species in biological tissues. It is characterized by efficient sample preparation and fast simultaneous analysis of Cr species with parallel total Cr analysis serving for chromium balance evaluation.

• Klíčová slova
• Biological tissues, Chromium, HPLC, ICP-MS, Speciation analysis,
• MeSH
• chrom * MeSH
• chromatografie iontoměničová MeSH
• hmotnostní spektrometrie MeSH
• spektrální analýza MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chrom * MeSH

A method for the determination and quantification of collagen types I-V in rat tissues has been developed. This method is based on collagen fragmentation by cyanogen bromide followed by trypsin digestion. After that, HPLC-MS/MS (HPLC coupled to an IT mass spectrometer) analyses of the resulting peptide mixtures (peptide maps) were performed. Specific peptides for each collagen type were selected. According to online databases, these peptides are present in human, bovine, and rat collagens. As a result, this method can be potentially applied to other species' tissues as well, such as human tissues, and provides a universal and simple method of quantifying collagen types. The applicability of this method for analyzing collagen types was demonstrated on rat tissues (skin, tendon, and aorta).

• MeSH
• kalibrace MeSH
• kolagen analýza   genetika   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• Lod skóre MeSH
• protein - isoformy analýza   genetika   MeSH
• sekvence aminokyselin MeSH
• skot MeSH
• tandemová hmotnostní spektrometrie MeSH
• tkáňové extrakty chemie   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kolagen MeSH
• protein - isoformy MeSH
• tkáňové extrakty MeSH

The study aimed to establish and validate an analytical method for the determination of nabumetone and 6-methoxy-2-naphthylacetic acid (6-MNA) in human plasma after a single therapeutic dose of the drug. Two methods based on HPLC with UV and MS detection were compared. Optimal results in sample preparation were achieved using solid phase extraction. The recovery reached approximately 84% and 86-90% for nabumetone and 6-MNA, respectively. A reverse C18 column was used for HPLC separation of the analytes. The limit of UV detection was 50 nM and 0.1 microM for 6-MNA and nabumetone, respectively. The limit of MS detection was 1 microM and 0.5 microM for 6-MNA and nabumetone, respectively. Precision ranged between 4.2-14.4% and 4.6-8.5% using UV and MS detection for nabumetone, respectively. The respective values for 6-MNA were 2.4-12.5% and 2.1-9.4%. Accuracy ranged between 93.4-109.6% in UV detection and 86.2-107.9% using UV and MS detection for nabumetone, respectively. The respective values for 6-MNA were 87.8-107.4% and 86.3-106.4%. The method was subsequently applied to determine the pharmacokinetic parameters of nabumetone and 6-MNA in a group of 24 healthy volunteers.

• MeSH
• butanony krev   MeSH
• hmotnostní spektrometrie * MeSH
• inhibitory enzymů krev   MeSH
• kyseliny naftalenoctové krev   MeSH
• lidé MeSH
• nabumeton MeSH
• spektrofotometrie ultrafialová * MeSH
• vysokoúčinná kapalinová chromatografie * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 6-methoxy-2-naphthylacetic acid MeSH Prohlížeč
• butanony MeSH
• inhibitory enzymů MeSH
• kyseliny naftalenoctové MeSH
• nabumeton MeSH