Arsenobetaine

Arsenobetaine is an organoarsenic compound that is the main source of arsenic found in fish.[1][2][3][4] It is the arsenic analog of trimethylglycine, commonly known as betaine. The biochemistry and its biosynthesis are similar to those of choline and betaine.

Arsenobetaine
Structural formula of arsenobetaine
Ball-and-stick model of arsenobetaine
Names
Preferred IUPAC name
(Trimethylarsaniumyl)acetate
Identifiers
3D model (JSmol)
3933180
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard100.162.654 Edit this at Wikidata
EC Number
  • 634-697-3
KEGG
MeSHArsenobetaine
RTECS number
  • CH9750000
UNII
  • InChI=1S/C5H11AsO2/c1-6(2,3)4-5(7)8/h4H2,1-3H3 ☒N
    Key: SPTHHTGLGVZZRH-UHFFFAOYSA-N ☒N
  • InChI=1/C5H11AsO2/c1-6(2,3)4-5(7)8/h4H2,1-3H3
    Key: SPTHHTGLGVZZRH-UHFFFAOYAQ
  • C[As+](C)(C)CC(=O)[O-]
  • C[As+](C)(C)CC([O-])=O
Properties
C5H11AsO2
Molar mass177.99/ g.mol−1
Hazards
GHS labelling:
GHS06: ToxicGHS09: Environmental hazard
Danger
H301, H331, H410
P261, P264, P270, P271, P273, P301+P310, P304+P340, P311, P321, P330, P391, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Arsenobetaine is a common substance in marine biological systems and unlike many other organoarsenic compounds, such as trimethylarsine, it is relatively non-toxic.[5][6] The compound may play a similar role as urea does for nitrogen, as a non-toxic waste compound made in the bodies of animals to dispose of the relevant element.

It has been known since 1920 that marine fish contain organoarsenic compounds, but it was not until 1977 that the chemical structure of the most predominant compound arsenobetaine was determined.[7]

Safety

Whereas arsenous acid (As(OH)3) has an LD50 (mice) of 34.5 mg/kg (mice), the LD50 for the arsenobetaine exceeds 10 g/kg.[8]

References

Further reading