Arsenosugars, also known as arsenic-containing ribofuranosides, are a class of organoarsenic compound and ribose derivative predominantly found in algae, seaweed and marine animals.

Structure

Chemical structure of oxo-arsenosugars and several common functional groups

There are several types of arsenosugar with the main ones being: oxo-, where an oxygen is double bonded to the arsenic; thio-, where a sulfur double bonds to the arsenic; and methyl-arsenosugars, where the arsenic atom is bonded to 2 or 3 methyl groups. The R-group represents an organic group with common ones being glycerol, sulfate, sulfonate and phosphate. There are a total of over 70 known arsenosugars with a known structure.

Occurrence and production

Arsenosugars were first isolated and identified in 1981 from Ecklonia radiata and are found predominantly in marine organisms. Arsenosugars are produced by some algae and bacteria, such as Synechocystis and Chlorella vulgaris which can convert inorganic arsenic, such as arsenite ions, into various organo-arsenic compounds including methlyarsenous acid and dimethylarsinous acid which then get converted to arsenosugars. These arsenosugars may then further be converted into arsenolipids.

Toxicity

Compared to many other organo-arsenic compounds, but similar to arsenobetaine, arsenosugars are generally non-toxic and pose less of a health concern to humans. However, some possible products of metabolism can be toxic, however, little research has been performed into their exact toxicities.