Arsenic compounds phosphatidylarsenocholine

The application of high-sensitivity ICP-MS detectors coupled to HPLC has enabled the detection of trace arsenic compounds present in marine animals. Thus, arsenocholine has been reported as a trace constituent (<0.1% of the total arsenic) in fish, molluscs, and crustaceans (37) and was found to be present in appreciable quantities (up to 15%) in some tissues of a marine turtle (110). Earlier reports (46,47) of appreciable concentrations of arsenocholine in some marine animals appear to have been in error (32). Phosphatidylarsenocholine 45 was identified as a trace constituent of lobster digestive gland following hydrolysis of the lipids and detection of GPAC in the hydrolysate by HPLC/ICP-MS analysis (70). It might result from the substitution of choline with arsenocholine in enzyme systems for the biogenesis of phosphatidylcholine (111). 

Lipid arsenic compounds also occur in marine animals (34,110). The compounds originally present in the lipid fraction were subjected to base and/or acid hydrolysis, and the water-soluble products identified by HPLC-ICPMS. In this way, phosphatidylarsenocholine (see Fig. 2, compound 18) and a phosphatidyl-arsenosugar (see Fig. 2, compound 5) were identified in the digestive gland of lobster (34), and evidence was presented for the presence of lipids containing arsenocholine and dimethylated arsenic moieties in shark tissues (110). 

Uptake of ingested organoarsenicals has also been investigated (67). Separate groups of yelloweye mullet were administered one of five organoarsenic compounds (7, 8, 39, 40, 41). Analysis of the arsenic concentrations in the fish and comparison with a control group showed that the three dimethylated compounds DMAE (39), 40, and 41 were not accumulated by the fish (an accumulation of >0.1% would have been detected), whereas both arsenobetaine and arsenocholine were readily accumulated. Importantly, arsenocholine was rapidly transformed to arsenobetaine within the fish minor metabolites were GPAC and phosphatidylarsenocholine 45. 

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See also in sourсe #XX -- [ , , ]

See also in sourсe #XX -- [ , , ]

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