Occurrence of Dimethyl-β-Propiothetin in Marine Phytoplankton

Abstract

Dimethyl-β-propiothetin has been reported from several species of freshwater and marine multicellular algae. Cultures of 14 species of unicellular marine algae were treated with cold aqueous alkali. Dimethyl sulphide was liberated from Syracosphaera carterae, Skeletonema costatum, Amphidinium carteri, Phaeodactylum tricornutum, Tetraselmis sp. and Cyclotella cryptica, and is assumed to arise from dimethyl-β-propiothetin. The amounts of alkali-labile material varied, on a wet weight basis, from 0.07 to 2.9% (as thetin salt) in different organisms. The presence of the thetin in S. carterae was confirmed by other means. The thetin, and particularly its degradation products, acrylic acid and dimethyl sulphide, may influence actual fishing operations and also affect the quality of fishery products. The metabolic and ecological significance of these materials are reviewed and discussed.