Novel drimane-type sesquiterpenoids and nucleosides from the Helicoma septoconstrictum suppress the growth of ovarian cancer cells.

[Display omitted] • This paper has showed four new drimane-type sesquiterpenoids and two new nucleosides from the Helicoma septoconstrictum. • Helicoside C (compounds 4) mediated intracellular ROS and mitochondrial dependent apoptosis in ovarian cancer A2780 cells. • Helicoside C could suppress the STAT3′s phosphorylation in A2780 cells. Four new drimane-type sesquiterpenoids and two new nucleoside derivatives (1–6), were isolated from the fungus Helicoma septoconstrictum. Their structures were determined based on the combination of the analysis of their HR-ESI-MS, NMR, ECD calculations data and acid hydrolysis. All the isolated compounds were detected for their bio-activities against MDA-MB-231, A549/DDP, A2780 and HepG2 cell lines. Helicoside C (4) exhibited superior cytotoxicity against the A2780 cell line with IC 50 7.5 ± 1.5 µM. The analysis of reactive oxygen species (ROS) revealed that Helicoside C induced an increase in intracellular ROS. Furthermore, the flow cytometry and mitochondrial membrane potential (MMP) analyses unveiled that Helicoside C mediated mitochondrial-dependent apoptosis in A2780 cells. The western blotting test showed that Helicoside C could suppress the STAT3′s phosphorylation. These findings offered crucial support for development of H. septoconstrictum and highlighted the potential application of drimane-type sesquiterpenoids in pharmaceuticals. [ABSTRACT FROM AUTHOR]