On the basis of the 'one strain, many compounds' (OSMAC) strategy, chemical investigation of the marine-derived fungus Trichothecium roseum resulted in the isolation of trichomide cyclodepsipeptides (compounds 1⁻4) from PDB medium, and destruxin cyclodepsipeptides (compounds 5⁻7) and cyclonerodiol sesquiterpenes (compounds 8⁻10) from rice medium. The structures and absolute configurations of novel (compounds 1, 8, and 9) and known compounds were elucidated by extensive spectroscopic analyses, X-ray crystallographic analysis, and ECD calculations. All isolated compounds were evaluated for cytotoxic, nematicidal, and antifungal activities, as well as brine shrimp lethality. The novel compound 1 exhibited significant cytotoxic activities against the human cancer cell lines MCF-7, SW480, and HL-60, with IC50 values of 0.079, 0.107, and 0.149 μM, respectively. In addition, it also showed significant brine shrimp lethality, with an LD50 value of 0.48 μM, and moderate nematicidal activity against Heterodera avenae, with an LC50 value of 94.9 μg/mL. This study constitutes the first report on the cytotoxic and nematicidal potential of trichomide cyclodepsipeptides.
Keywords: cyclodepsipeptides; cytotoxic activity; marine-derived fungus; nematicidal activity; sesquiterpenes.