Speciation of arsenic compounds in some marine organisms

1994 ◽  
Vol 28 (9) ◽  
pp. 1598-1604 ◽  
Author(s):  
Sean X. C. Le ◽  
William R. Cullen ◽  
Kenneth J. Reimer
2009 ◽  
Vol 60 (9) ◽  
pp. 885 ◽  
Author(s):  
W. Maher ◽  
S. Foster ◽  
F. Krikowa

Although over 50 arsenic species have been identified in marine organisms, the biochemical pathways by which these species are formed are not known. In this paper, we present an overview of bioconversions of arsenic species that occur in marine food chains based on studies conducted by our laboratory as well as the work of others. Phytoplankton and macroalgae only contain dimethylarsenoribosides or simple methylated arsenic compounds such as dimethylarsenate and dimethylarsenoethanol. Marine animals contain mostly arsenobetaine and a range of other arsenic species that may be precursors of arsenobetaine formation. The formation of arsenobetaine in marine animals from dimethylarsenoribosides may occur through a two-stage conversion pathway: arsenoriboside or trimethylarsonioriboside degradation to arsenocholine followed by quantitative oxidation to arsenobetaine. The minor arsenic species found in marine organisms are sulfur analogues of compounds found in the S-adenosylmethionine-methionine salvage and the dimethylsulfoniopropionate metabolic pathway of animals. A key intermediate in these pathways would be arsenomethionine, which could possibly be formed from dimethylarsinite, dimethylarsenoribosides or an arsenic-containing analogue of S-adenosylmethionine. Examining arsenic species in whole ecosystems has the advantage of using the pattern of arsenic species found to postulate the biochemical pathways of their formation.


2010 ◽  
Vol 82 (2) ◽  
pp. 373-381 ◽  
Author(s):  
Kevin A. Francesconi

The presence of arsenic in marine samples was first reported over 100 years ago, and shortly thereafter it was shown that common seafood such as fish, crustaceans, and molluscs contained arsenic at exceedingly high concentrations. It was noted at the time that this seafood arsenic was probably present as an organically bound species because the concentrations were so high that if the arsenic had been present as an inorganic species it would certainly have been toxic to the humans consuming seafood. Investigations in the late 1970s identified the major form of seafood arsenic as arsenobetaine [(CH3)3As+CH2COO–], a harmless organoarsenic compound which, following ingestion by humans, is rapidly excreted in the urine. Since that work, however, over 50 additional arsenic species have been identified in marine organisms, including many important food products. For most of these arsenic compounds, the human toxicology remains unknown. The current status of arsenic in seafood will be discussed in terms of the possible origin of these compounds and the implications of their presence in our foods.


1993 ◽  
Vol 10 (4) ◽  
pp. 421 ◽  
Author(s):  
J. S. Edmonds ◽  
K. A. Francesconi ◽  
R. V. Stick

ChemInform ◽  
2010 ◽  
Vol 25 (11) ◽  
pp. no-no
Author(s):  
J. S. EDMONDS ◽  
K. A. FRANCESCONI ◽  
R. V. STICK

Author(s):  
V. Ramadas ◽  
G. Chandralega

Sponges, exclusively are aquatic and mostly marine, are found from the deepest oceans to the edge of the sea. There are approximately 15,000 species of sponges in the world, of which, 150 occur in freshwater, but only about 17 are of commercial value. A total of 486 species of sponges have been identified in India. In the Gulf of Mannar and Palk Bay a maximum of 319 species of sponges have been recorded. It has been proved that marine organisms are excellent source of bioactive secondary metabolites and number of compounds of originated from marine organisms had been reported to possess in-vitro and in-vivo immuno stimulatory activity. Extracts from 20 sponge species were tested for bacterial symbionts and bioactive compounds were isolated from such associated bacterial species in the present study.


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