Lotaustralin is a cyanogenic glucoside found in small amounts in tropical root crop cassava (Manihot esculenta), lima bean (Phaseolus lunatus), roseroot (Rhodiola rosea) and other plants. Lotaustralin is the glucoside of methyl ethyl ketone cyanohydrin and a precursor to the toxic compound hydrogen cyanide. Extracted from Rhodiola sacra lotaustralin potently inhibited the histamine release from rat peritoneal exudate cells induced by an antigen-antibody reaction exhibiting antiallergic activity.