Aβ-42 lowering agents from the marine-derived fungus Dichotomomyces cejpii.

The ascomycete Dichotomomyces cejpii was isolated from the marine sponge Callyspongia cf. C. flammea. Three new steroids (1-3), two of which are present as glycosides, with an untypical pattern of carbon-carbon double bounds, were obtained from fungal extracts, as well as the known xanthocillin X dimethyl ether (4). Compounds 2 and 4 were evaluated in an Alzheimer's disease cellular assay and found capable of preventing the enhanced production of amyloid β-42 in Aftin-5 treated cells. Aβ-42 lowering agents are considered as candidates for the treatment of neurodegenerative Alzheimer's disease.