A5071414120- Metabolomics and Mass Spectrometry Studies
- Analytical Chemistry and Chromatography
- Mass Spectrometry Techniques and Applications
- Analytical chemistry methods development
- Natural product bioactivities and synthesis
- Advanced Chemical Sensor Technologies
- Fermentation and Sensory Analysis
- NMR spectroscopy and applications
- Molecular spectroscopy and chirality
- Atmospheric chemistry and aerosols
- Malaria Research and Control
- Phytochemistry and Biological Activities
- Atmospheric Ozone and Climate
- Pesticide Residue Analysis and Safety
- Pharmacological Effects of Natural Compounds
- Phytochemicals and Antioxidant Activities
- Essential Oils and Antimicrobial Activity
- Spectroscopy and Laser Applications
- Water Quality Monitoring and Analysis
- Ginseng Biological Effects and Applications
- Metabolism and Genetic Disorders
- Parasitic Diseases Research and Treatment
- Analytical Methods in Pharmaceuticals
- Plant biochemistry and biosynthesis
- Electrochemical Analysis and Applications
Bruker (Germany)
2013-2024
Bruker (United States)
2002-2020
Bruker (Switzerland)
2009
Bruker (France)
2008
University of Arizona
2007
University of Ioannina
2003
University of Aveiro
2003
Fraunhofer Society
1996-1999
Fraunhofer Institute for Toxicology and Experimental Medicine
1997-1998
Structure elucidation of natural products usually relies on a combination NMR spectroscopy with mass spectrometry whereby trails MS in terms the minimum sample amount required. In present study, usefulness on-line solid-phase extraction (SPE) LC-NMR for peak storage after LC separation prior to analysis is demonstrated. The SPE unit allows use normal protonated solvents and fully deuterated flushing trapped compounds probe. Thus, solvent suppression no longer necessary. Multiple trapping...
Bacteria are a major source of natural products that provide rich opportunities for both chemical and biological investigation. Although the vast majority known bacterial metabolites derive from free-living organisms, increasing evidence supports widespread existence chemically prolific bacteria living in symbioses. A strategy based on bioinformatic prediction, symbiont cultivation, isotopic enrichment, advanced analytics was used to characterize unique polyketide, nosperin,...
Directly coupled HPLC−NMR−MS was used to identify and confirm the presence of quercetin O-glycosides phloretin in an extract apple peel. From MS MS/MS data, molecular weights intact molecules as well those their sugar moieties were deduced. The NMR data provided information on identity compounds α β conformations position glycosides phloretin. following could be identified: quercetin-3-α-l-rhamnosyl-(1 → 6)-β-d-glucoside (rutin), quercetin-3-β-d-galactoside (hyperin),...
The aim of this study was to investigate the antinociceptive and anti-inflammatory activities epiisopiloturine (1), an imidazole alkaloid found in leaves Pilocarpus microphyllus. activity 1 evaluated using several agents that induce paw edema peritonitis Swiss mice. Paw tissue peritoneal fluid samples were obtained determine myeloperoxidase (MPO) or tumor necrosis factor (TNF)-α interleukin (IL)-1β levels. by acetic acid-induced writhing, hot plate test, pain induction formalin. Compared...
When small B lymphocytes bind antigen in the context of suitable signals, a profound geno-proteomic metamorphosis is activated that generates antibody-secreting cells. To study metabolic changes associated with this differentiation program, we compared exometabolome differentiating murine lymphoma cells and primary by monodimensional proton nuclear magnetic resonance spectroscopy mass spectrometry coupled to liquid chromatography. Principal component analysis, multivariate statistical...
LC-DAD-MS monitored fractionation of a Harpagophytum procumbens DC. (Pedaliaceae) root extract was combined with hyphenated LC-DAD-MS/SPE-NMR technique, thus providing the spectral data needed for structure elucidation. This approach allowed characterization isobaric iridoid glycoside regioisomers present only as minor constituents. The analytes were identified (E/Z) pairs 6'-O-(p-coumaroyl)harpagide (6'-PCHG) and 8-O-(p-coumaroyl)-harpagide (8-PCHG). fact that 8-(Z)-PCHG constitutes new...
Abstract Mass drug administration of ivermectin has been proposed as a possible malaria elimination tool. Ivermectin exhibits mosquito‐lethal effect well beyond its biological half‐life, suggesting the presence active slowly eliminated metabolites. Human liver microsomes, primary human hepatocytes, and whole blood from healthy volunteers given oral were used to identify metabolites by ultra‐high performance liquid chromatography coupled with high‐resolution mass spectrometry. The molecular...
Phytochemical investigation of a supercritical fluid extract Glycyrrhiza uralensis has led to the isolation 20 known isoflavonoids and coumarins, glycycarpan (7), new pterocarpan. The presence two isoflavan-quinones, licoriquinone A (8) B (9), in fraction subjected gel filtration on Sephadex LH-20 is due suspected metal-catalyzed oxidative degradation licoricidin (1) licorisoflavan (2). major compounds extract, as well 8, were evaluated for their ability inhibit growth several oral...
The application of LC-NMR/MS for the direct identification carbohydrates in beer has been studied. Carbohydrates are major components, and their structural characterization by NMR alone is seriously hindered strong spectroscopic overlap. Direct analysis enables rapid (1−2 h) dextrins with degree polymerization (DP) up to nine monomers, degassing being only sample treatment required. Although presence α(1→6) branching points easily indicated each subfraction separated LC, difficulties arise...
Metabolism is essential to understand human health. To characterize metabolism, a high-resolution read-out of the metabolic status under various physiological conditions, either in health or disease, needed. Metabolomics offers an unprecedented approach for generating system-specific biochemical definitions phenotype through capture variety metabolites single measurement. The emergence large cohorts clinical studies increases demand technologies able analyze number measurements, automated...
Recently the number of studies investigating triterpenoid saponins has drastically increased due to their diverse and potentially attractive biological activities. Currently literature contains chemical structures few hundreds plant animal origin. Triterpenoid consist a triterpene aglycone with one or more sugar moieties attached it. However, similar physico-chemical properties, isolation identification large diversity remain challenging. This study demonstrates methodology screen using...
Coupling of HPLC to NMR was applied for the first time analysis environmental samples, i.e., water samples from an ammunition hazardous waste site. Using continuous flow mode at very low rates (< or = 0.017 mL/min) and large volume injection (400 microL), confirmation many nitroaromatic compounds could be achieved down microgram-per-liter level after solid phase extraction a groundwater sample former production At rate 0.006 mL/min, it is possible detect less than 29 nmol (5 micrograms)...
Human cytochrome P450 3A4 forms a series of minor testosterone hydroxylation products in addition to 6β‐hydroxytestosterone, the major product. One these, formed at next highest rate after 6β‐ and 2β‐hydroxy products, was identified as 1β‐hydroxytestosterone. This product characterized from mixture oxidation using an HPLC‐solid phase extraction‐cryoprobe NMR/time‐of‐flight mass spectrometry system, with estimated total ≈ 6 µg this Mass established formula C 19 H 29 O 3 (MH + 305.2080). The...
Dehydroabietic acid (DHA) (1) is one of the main compounds in Scots pine wood responsible for aquatic and microbial toxicity. The degradation 1 by Trametes versicolor Phlebiopsis gigantea liquid stationary cultures was followed HPLC-DAD-ELSD. Both fungi rapidly degraded DHA relative to a control. More breakdown products were observed T. than P. gigantea. After 13 days, four identified means spectroscopic methods cultures: 1beta-hydroxy-DHA (2), 1beta,7alpha-dihydroxy-DHA (3),...
This paper presents an industrial scale process for extraction, purification, and isolation of epiisopiloturine (EPI) (2(3H)-Furanone,dihydro-3-(hydroxyphenylmethyl)-4-[(1-methyl-1H-imidazol-4-yl)methyl]-, [3S-[3a(R*),4b]]), which is alkaloid from jaborandi leaves (Pilocarpus microphyllus Stapf). Additionally the first time a set structural spectroscopic techniques were used to characterize this alkaloid. EPI has shown schistomicidal activity against adults young forms, as well reduction egg...
The aim of the present study was to explore capabilities combination 1H NMR (proton nuclear magnetic resonance) mixture analysis and HPLC-SPE-NMR/TOF-MS (high-performance liquid chromatography coupled solid-phase extraction resonance time-of-flight mass spectrometry) for characterization xenobiotic contaminants in groundwater samples. As an example, extracts two samples taken from a former ammunition destruction site Switzerland were investigated. spectra postcolumn SPE enriched compounds,...
Two methods for the quantitative determination of compounds in continuous-flow HPLC/NMR are described. The first method uses an internal standard (caffeine) known concentration directly mixed into mobile phase, while with second method, a amount is injected onto column during chromatographic run. latter was validated using several nitroaromatic and explosives. Deviations between calculated amounts analytes usually below 10% relative deviation ranges from 2% upper microgram range to 40% at...