Alternariol 9-O-methyl ether dimethyl sulfoxide monosolvate.

3,7-dihy-droxy-9-meth-oxy-1-methyl-6H-benzo[c]chromen-6-one dimethyl sulfoxide monosolvate), C15H12O5·C2H6OS, was isolated from an unidentified endophytic fungus (belonging to class Ascomycetes) of Taxus sp. In the crystal, both the alternariol 9-O-methyl ether (AME) and the dimethyl sulfoxide (DMSO) mol-ecules exhibit crystallographic mirror symmetry. One of the hy-droxy groups makes bifurcated hydrogen bonds, viz. an intra-molecular bond with the carbonyl group and an inter-molecular bond with the carbonyl group in an inversion-related AME mol-ecule. In the crystal, the AME mol-ecules are organized into stacks parallel with the b axis by π-π inter-actions between centrosymmetrically related mol-ecules [the distance between the centroid of the central ring and the centroid of the meth-oxy-substituted benzene ring in the next mol-ecule of the stack is 3.6184 (5) Å]. Pairs of DMSO mol-ecules, linked via centrosymmetric C-H⋯O contacts, are inserted into the voids created by the AME mol-ecules, making O-H⋯O and C-H⋯O contacts with the hosts.