ORCID Profile
0000-0002-2536-0542
Current Organisation
University of Graz
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Publisher: American Chemical Society (ACS)
Date: 07-11-2018
Publisher: Elsevier BV
Date: 12-2018
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/ENV17N5_ED
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9JA00249A
Abstract: Arsenolipids detected in the brain of the marine fish skipjack tuna ( Katsuwonus pelamis ) using HPLC/mass spectrometry.
Publisher: Wiley
Date: 21-03-2016
Publisher: Oxford University Press (OUP)
Date: 2018
DOI: 10.1039/C7MT00249A
Abstract: Culture experiments exposing unicellular algae to varying arsenate hosphate regimes and determining their arsenometallomes by HPLC–MS shows the interconnection of arsenolipids and water-soluble arsenicals.
Publisher: Wiley
Date: 21-03-2016
Publisher: Wiley
Date: 17-08-2017
Publisher: Wiley
Date: 17-08-2017
Abstract: Lipid-soluble arsenic compounds, also called arsenolipids, are ubiquitous marine natural products of currently unknown origin and function. In our search for clues about the possible biological roles of these compounds, we investigated arsenic metabolism in the unicellular green alga Dunaliella tertiolecta, and discovered an arsenolipid fundamentally different from all those previously identified namely, a phytyl 5-dimethylarsinoyl-2-O-methyl-ribofuranoside. The discovery is of particular interest because 2-O-methylribosides have, until now, only been found in RNA. We briefly discuss the significance of the new lipid in biosynthesis and arsenic biogeochemical cycling.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8JA00276B
Abstract: An HPLC/ICP-QQQ-MS method for the simultaneous quantitative determination of the health relevant anti-oxidant ergothioneine and its selenium-analogue selenoneine in blood cells is presented.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7JA00030H
Abstract: A HPLC/ICP-QQQ-MS method for quantifying the health-relevant sulfur species ergothioneine was developed and applied to human cells and mushrooms.
Publisher: American Chemical Society (ACS)
Date: 02-01-2018
Publisher: Oxford University Press (OUP)
Date: 2018
DOI: 10.1039/C8MT00200B
Abstract: Selenoneine, a naturally occurring form of selenium, is the selenium analogue of ergothioneine, a sulfur species with health relevance not only as a purported antioxidant but likely also beyond. Selenoneine has been speculated to exhibit similar effects. To study selenoneine's health properties as well as its metabolic transformation, the pure compound is required. Chemical synthesis of selenoneine, however, is challenging and biosynthetic approaches have been sought. We herein report the biosynthesis and isolation of selenoneine from genetically modified fission yeast Schizosaccharomyces pombe grown in a medium containing sodium selenate. After cell lysis and extraction with methanol, selenoneine was purified by three consecutive preparative reversed-phase HPLC steps. The product obtained at the mg level was characterised by high resolution mass spectrometry, NMR and HPLC/ICPMS. Biosynthesis was found to be a promising alternative to chemical synthesis, and should be suitable for upscaling to produce higher amounts of this important selenium species in the future.
Publisher: American Chemical Society (ACS)
Date: 28-12-2018
Abstract: Arsenic occurs in marine waters, typically at concentrations of 1-2 μg As kg
Publisher: American Chemical Society (ACS)
Date: 10-12-2018
Publisher: American Chemical Society (ACS)
Date: 31-03-2021
Publisher: Oxford University Press (OUP)
Date: 27-05-2020
DOI: 10.1039/D0MT00073F
Abstract: Arsenolipids include a wide range of organic arsenic species that occur naturally in seafood and thereby contribute to human arsenic exposure. Recently arsenic-containing phosphatidylcholines (AsPCs) were identified in caviar, fish, and algae. In this first toxicological assessment of AsPCs, we investigated the stability of both the oxo- and thioxo-form of an AsPC under experimental conditions, and analyzed cell viability, indicators of genotoxicity and biotransformation in human liver cancer cells (HepG2). Precise toxicity data could not be obtained owing to the low solubility in the cell culture medium of the thioxo-form, and the ease of hydrolysis of the oxo-form, and to a lesser degree the thioxo-form. Hydrolysis resulted amongst others in the respective constituent arsenic-containing fatty acid (AsFA). Incubation of the cells with oxo-AsPC resulted in a toxicity similar to that determined for the hydrolysis product oxo-AsFA alone, and there were no indices for genotoxicity. Furthermore, the oxo-AsPC was readily taken up by the cells resulting in high cellular arsenic concentrations (50 μM incubation: 1112 ± 146 μM As cellular), whereas the thioxo-AsPC was substantially less bioavailable (50 μM incubation: 293 ± 115 μM As cellular). Speciation analysis revealed biotransformation of the AsPCs to a series of AsFAs in the culture medium, and, in the case of the oxo-AsPC, to as yet unidentified arsenic species in cell pellets. The results reveal the difficulty of toxicity studies of AsPCs in vitro, indicate that their toxicity might be largely governed by their arsenic fatty acid content and suggest a multifaceted human metabolism of food derived complex arsenolipids.
Start Date: 2008
End Date: 2012
Funder: National Institutes of Health
View Funded ActivityStart Date: 2008
End Date: 2012
Funder: US National Institutes of Health
View Funded Activity