Xanthurenic Acid Monohydrate

In the structure of the title compound, 4,8-dihydroxy-2-quinoline­carboxylic acid monohydrate, C₁₀H₇NO₄.H₂O, the ionized carboxyl group is located in the quinoline ring plane and the N atom of the ring is protonated so that it is positively charged, i.e. the compound may be named 4,8-dihydroxyquinolinium-2-carboxylate monohydrate. The crystal structure is stabilized by intermolecular O—H...O hydrogen bonds involving the water molecule.

-1