The crystal and molecular structure of ellagic acid dihydrate: a dietary anti-cancer agent.

The crystal and molecular structure of ellagic acid dihydrate has been determined by X-ray diffraction techniques. This acid inhibits the carcinogenic properties of a variety of chemical compounds including benzo[alpha]pyrene-7,8-diol-9,10-epoxide, aflatoxin B1, N-methyl-N-nitrosourea, 3-methyl-cholanthrene and 7,12-dimethylbenz[alpha]anthracene. Ellagic acid dihydrate forms triclinic crystals with unit cell dimensions: a = 7.656(1) A, b = 9.563(1)A, c = 4.623(1) A, alpha = 97.88(1) degrees, beta = 103.2(1) degrees, gamma = 102.22(1) degrees, V = 315.9 A3, space group = P1. There is a center of symmetry in the crystal coinciding with the center of the molecule, so that there is only one molecule in the unit cell. Ellagic acid is planar and molecules are interconnected by hydrogen bonds to water, giving rise to layers of molecules throughout the crystal. Its activity and anti-cancer properties are compared with those of a similar naturally occurring compound, quercetin.