Chemical demethylation of methylmercury by selenoamino acids.

A new chemical demethylation pathway for methylmercury under physiologically and environmentally relevant conditions is reported. The pathway involves the reaction between methylmercury and a selenoamino acid (L-selenocysteine, L-selenoglutathione, D,L-selenopenicillamine, or L-selenomethionine) via the formation of bis(methylmercuric)selenide and dimethylmercury as intermediates. The final degradation product is HgSe(s).