(22E,24R)-3β,5α,9α-Trihy-droxy-ergosta-7,22-dien-6-one monohydrate.

The title ergosterol compound, C(28)H(44)O(4)·H(2)O, is composed of four fused rings (three six-membered and one five-membered) and a side chain. It is a derivative of ergosterol and was isolated from a marine-derived halotolerant fungus, Cladosporium cladosporioides PXP-49. In the crystal, mol-ecules are assembled by classical O-H⋯O hydrogen bonds, forming a two-dimensional network, with base vectors [100] and [010]. The absolute configuration was assigned from the measured optical rotation and reference to the literature. An intra-molecular O-H⋯O hydrogen bond occurs.