Oosporein from Tremella fuciformis

The title compound [systematic name: 3,3′,6,6′-tetra­hydroxy-4,4′-dimethyl-1,1′-bi(cyclo­hexa-3,6-diene)-2,2′,5,5′-tetra­one], C(14)H(10)O(8), was isolated from Tremella fuciformis. The mol­ecule has 2 symmetry, with the mid-point of the C—C bond linking the cyclo­hexa­dienedione rings located on a twofold rotation axis. In the mol­ecule, the ring is approximately planar, with an r.m.s. deviation of 0.0093 Å, and the two rings make a dihedral angle of 67.89 (5)°. Inter­molecular O—H⋯O hydrogen bonding occurs in the crystal structure.