Dithiodiketopiperazine derivatives from endophytic fungi <i>Trichoderma harzianum</i> and <i>Epicoccum nigrum</i> HarwokoHarwoko DaletosGeorgios StuhldreierFabian LeeJungho WesselborgSebastian FeldbrüggeMichael E. G. MüllerWerner KalscheuerRainer AncheevaElena ProkschPeter 2019 <p>A new epidithiodiketopiperazine (ETP), pretrichodermamide G (<b>1</b>), along with three known (epi)dithiodiketopiparazines (<b>2-4</b>) were isolated from cultures of <i>Trichoderma harzianum</i> and <i>Epicoccum nigrum</i>, endophytic fungi associated with medicinal plants <i>Zingiber officinale</i> and <i>Salix</i> sp., respectively. The structure of the new compound (<b>1</b>) was established on the basis of spectroscopic data, including 1D/2D NMR and HRESIMS. The isolated compounds were investigated for their antifungal, antibacterial and cytotoxic potential against a panel of microorganisms and cell lines. Pretrichodermamide A (<b>2</b>) displayed antimicrobial activity towards the plant pathogenic fungus <i>Ustilago maydis</i> and the human pathogenic bacterium <i>Mycobacterium tuberculosis</i> with MIC values of 1 mg/mL (2 mM) and 25 µg/mL (50 µM), respectively. Meanwhile, epicorazine A (<b>3</b>) exhibited strong to moderate cytotoxicity against L5178Y, Ramos, and Jurkat J16 cell lines with IC<sub>50</sub> values ranging from 1.3 to 28 µM. Further mechanistic studies indicated that <b>3</b> induces apoptotic cell death.</p> <p></p>