Planteose, a carbohydrate isolated from tobacco seeds, can be hydrolyzed in dilute acid to yield one equiva-lent each of D-fructose, D-glucose, and D-galactose. Almond emulsion (an enzyme preparation that hydrolyzes a-galactosides) catalyzes the hydrolysis of planteose to D-galactosc and sucrose. Planteose does not react with bromine water. Treatment of planteose with (CH3)2SO4/NaOH, followed by dilute acid hydrolysis, yields, among other compounds, 1,3,4-tri-O-methyl-D-fructose. Suggest a structure for planteose.