Cytotoxic substances produced by a fungal strain from a sponge: physico-chemical properties and structures.

Five novel metabolites, trichodenones A-C (1-3), harzialactone A (4) and B (5), have been isolated together with known R-mevalonolactone (6) from the culture broth of a strain of Trichoderma harzianum OUPS-N115 originally separated from the sponge Halichondria okadai. Their structures have been elucidated by spectral evidence. Among them, 1-3 exhibited significant cytotoxicity against cultured P388 cells.