- a white, crystalline, water-soluble powder, C6H10O8, obtained by the oxidation of certain gums, milk sugar, or galactose, and used chiefly in organic synthesis.
- a colourless crystalline solid carboxylic acid found in milk sugar and used in the manufacture of pyrrole. Formula: C 4 H 4 (OH) 4 (COOH) 2
