The title compound, C(16)H(12)O(6)·H(2)O, isolated from the halotolerant fungus Aspergillus variecolor B-17, is also known as questinol monohydrate. In the crystal structure, O-H⋯O hydrogen bonds link the mol-ecules, forming a three-dimensional network. π-π stacking inter-actions consolidate the supra-molecular structure [the shortest inter-planar distances are 3.456 (3), 3.366 (4) and 3.382 (4) Å].