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organic compounds
Lactosylurea [(4-O--D-galactopyranosyl-1-N--D-glucopyranosyl)urea], C13H24N2O11.2H2O, crystallizes as a dihydrate in the space group P1. There are twelve distinct hydrogen bonds, including one intramolecular hydrogen bond joining the glucose and galactose rings. This structure determination establishes that the reaction of urea with lactose does not lead to rearrangement or to an acyclic form of lactose and that the urea forms a -N-glycoside linkage.