Determination of lipid‐soluble arsenic species in seaweed‐eating sheep from Orkney

Devalla, S; Feldmann, Jörg

doi:10.1002/aoc.550

Cited by 47 publications

(38 citation statements)

References 17 publications

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“…Although the watersoluble products from the enzyme treatments were incorrectly assigned at that time, they were later correctly ascribed to arsenosugars. [1,[15][16][17] Our definitive results on the structures of the major arsenolipids in algae are consistent with the earlier observations. Collectively, the data suggest that the arsenosugarphospholipids might be the target arsenic species synthesised by algae, and that the arsenosugars are merely degradation products of compounds excess to the algae's requirements.…”

supporting

confidence: 92%

Arsenosugar phospholipids and arsenic hydrocarbons in two species of brown macroalgae

et al. 2012

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Environmental context. Although organoarsenic compounds occur in marine organisms at high concentrations, the origin and role of these compounds is unknown. Arsenic-containing lipids (arsenolipids) are newly discovered compounds in fish. We identify a range of arsenolipids in algae and propose that algae are the origin of these unusual arsenic compounds in marine ecosystems.Abstract. Fourteen arsenolipids, including 11 new compounds, were identified and quantified in two species of brown algae, Wakame (Undaria pinnatifida) and Hijiki (Hizikia fusiformis), by high resolution mass spectrometry, high performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Both algal species contained arsenosugar-phospholipids as the major type of arsenolipid, and arsenic-hydrocarbons were also significant components, particularly in Hijiki. The origin of the various arsenolipids, and the possible significance of their relative quantities, is briefly discussed. Arsenic-containing organic compounds are abundant in marine ecosystems where they are thought to play a pivotal role in the cycling and detoxification of potentially toxic inorganic arsenic (arsenate) present in seawater. [1] Although most of the arsenic compounds identified so far have been water-soluble species, the early work on arsenic marine chemistry focussed on lipidsoluble compounds, so called arsenolipids. [2][3][4] Identification of these arsenolipids proved difficult, however, and it was not until 1988 that an arsenolipid was first rigorously characterised and identified as an arsenosugar-containing phospholipid [5] (see Table 1, compound As-PL958).Subsequently, the range of naturally occurring arsenolipids has been extended with the discovery of arsenic-containing fatty acids in fish oils, [6] and arsenic-containing hydrocarbons in fish oils, [7] fish liver, [8] sashimi tuna [9] and fish meal. [10] The origin of these compounds was presumed to be algae. We report the arsenolipid profiles of two species of brown algae, determined mainly by high performance liquid chromatography-mass spectrometry (HPLC-MS), and we briefly discuss the possible biosynthetic origin of these unusual compounds.Samples of Wakame (Undaria pinnatifida, 40 AE 3 mg As g À1 dry mass) and Hijiki (Hizikia fusiformis, 113 AE 5 mg As g À1 dry mass), A obtained from a Japanese commercial source, were extracted with a mixture of chloroform and methanol using a modification B of the classical procedure of Bligh and Dyer. [11] The lipid fraction containing 6.7 % (Wakame) and 1.6 % (Hijiki)A Determination of arsenic contents. Total arsenic analyses were performed on portions of the dry powders, extracts or combined fractions from the silica columns by ICP-MS (Agilent 7500ce) in helium collision cell mode following a microwave-assisted acid mineralisation step. The method was validated by analysis of reference material NIES No. 9 Sargasso (certified As content 115 AE 5 mg As g À1 ); we obtained 116 AE 2 mg As g À1 (n ¼ 3). BExtraction and purification of arsenolipid...

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confidence: 92%

Arsenosugar phospholipids and arsenic hydrocarbons in two species of brown macroalgae

et al. 2012

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“…Angiosperms have been shown to contain a low proportion and a limited number of polar lipids. 38 Arsenic lipids have been found to be associated with polar phospholipids in macro algae 39,40 and the absence of polar lipids in angiosperms may explain the low proportions of arsenic found in the lipid fractions of angiosperms in this study. The proportion of arsenic in the water-soluble fractions were also relatively low and not consistent between angiosperms (Table 8).…”

Section: Fractionation Of Arsenicmentioning

confidence: 66%

“…Internal standards were added on-line to compensate for any acid side effects and instrument drift. 21 The potential interference to arsenic (m/z 75) from 40 Other elements were corrected for interferences as outlined in Maher et al…”

Section: Total Arsenic and Element Analysismentioning

confidence: 99%

Arsenic and selected elements in marine angiosperms, south‐east coast, NSW, Australia

Thomson

Maher

Foster

2007

Applied Organom Chemis

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The leaves of four angiosperm species, the mangrove Avicennia marina, the samphire Sarcocornia quinqueflora, the seablight Suaeda australis and the seagrass Posidonia australis, were sampled from three locations from the south-east coast of NSW. Mean total arsenic concentrations (mean ± SD) in dry mass for all locations were A. marina (0.38 ± 0.18 to 1.2 ± 0.7 µg g −1 ), S. quinqueflora (0.13 ± 0.06 to 0.46 ± 0.22 µg g −1 ), S. australis (0.03 ± 0.06 to 0.05 ± 0.03 µg g −1 ) and P. australis (0.34 ± 0.10 to 0.65 ± 0.26 µg g −1 ). Arsenic concentrations were significantly different between species and locations but were consistently low compared with marine macroalgae species. Significant relationships were found between arsenic and iron concentrations for A. marina, S. quinqueflora and P. australis and a negative relationship between arsenic and zinc concentrations for S. quinqueflora. No relationship between arsenic and phosphorus concentrations was found in this study. Angiosperms contained predominantly inorganic arsenic in the water-extractable and residue fractions with minor concentrations of DMA in the water-soluble fraction. P. australis also contained dimethylated glycerol and phosphate arsenoriboses. The presence of arsenobetaine, arsenocholine, trimethylated glycerol arsonioribose and an unknown cation in P. australis is most likely due to the presence of epiphytes on fronds. There is no evidence to suggest that angiosperms produce arsenobetaine as arsenic is mostly present as inorganic arsenic. In conclusion, marine angiosperms only accumulate low arsenic concentrations and uptake appears to be dependent on iron uptake but not phosphorus uptake. Marine angiosperms mainly cycle inorganic arsenic with little biomethylation of arsenic occurring.

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“…The exact arsenic content of all arsonoliposome preparations was determined by graphite furnace atomic absorption spectroscopy (GFAAS), as previously described [20,21]. In brief, 20 lL of arsonoliposomes were digested with nitric acid at 808C and after this the residue was dissolved in a mixture of 0.5 mL 0.4% v/v nitric acid and 0.5 mL of H 2 O 2 .…”

Section: Preparation Of Arsonoliposomesmentioning

confidence: 99%

Does the lipid membrane composition of arsonoliposomes affect their anticancer activity? A cell culture study

Zagana

Haikou

Giannopoulou

et al. 2009

Molecular Nutrition Food Res

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Sonicated arsonoliposomes were prepared using arsonolipid with palmitic acid acyl chain (C16), mixed with phosphatidylcholine (PC)-based or 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)-based, and cholesterol (Chol) with C16/DSPC/Chol 8:12:10 molar ratio. PEG-lipid (1,2-distearoyl-sn-glycero-3-phosphoethanolamine conjugated to polyethylenoglycol 2000) containing vesicles (PEGylated-arsonoliposomes; PC-based and DSPC-based) were also prepared. The cytotoxicity of these arsonoliposomes towards different cancer cells (human promyelocytic leukaemia NB4, Prostatic cancer PC3, human breast adenocarcinoma MDA-MB-468, human T-lymphocyte (MT-4) and also towards human umbilical vein endothelial cells (HUVECs) was evaluated by calculating the arsonoliposome-induced growth inhibition of the cells by the MTT assay. IC-50 values were interpolated from cell number/arsonoliposome concentration curves. The results reveal that all types of arsonoliposomes evaluated significantly inhibit the growth of most of the cancer cells studied (PC3, NB4, MT4) with the exception of the MDA-MB-468 breast cancer cells which were minimally affected by arsonoliposomes; in some cases even less than HUVEC. Nevertheless, for the same cell type the differences between the different types of arsonoliposomes were significant but not proportional to their stability, indicating that the formation of arsonoliposomes with very stable membranes is not a problem for their anticancer activity. Thereby it is concluded that arsonoliposome composition should be adjusted in accordance to their in vivo kinetics and the desired, for each specific application, biodistribution of As and/or encapsulated drug.

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Determination of lipid‐soluble arsenic species in seaweed‐eating sheep from Orkney

Cited by 47 publications

References 17 publications

Arsenosugar phospholipids and arsenic hydrocarbons in two species of brown macroalgae

Arsenosugar phospholipids and arsenic hydrocarbons in two species of brown macroalgae

Arsenic and selected elements in marine angiosperms, south‐east coast, NSW, Australia

Does the lipid membrane composition of arsonoliposomes affect their anticancer activity? A cell culture study

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