Meroterpenoid Dimers from Ganoderma Mushrooms and Their Biological Activities Against Triple Negative Breast Cancer Cells

(±)-Dimercochlearlactones A−J (1–10), ten pairs of novel meroterpenoid dimers and one known spirocochlealactone A (11), were isolated from Ganoderma mushrooms. The structural elucidation of new compounds, including their absolute configurations, depends on spectroscopic analysis and electronic circular dichroism (ECD) calculations. Biological studies showed that (+)- and (–)-2, (–)-3, and (+)- and (–)-11 are cytotoxic toward human triple negative breast cancer (TNBC) cells (MDA-MB-231) with IC(50) values of 28.18, 25.65, 11.16, 8.18, and 13.02 μM, respectively. Wound healing assay revealed that five pairs of meroterpenoids (±)-5−(±)-8 and (±)-10 could significantly inhibit cell mobility at 20 μM in MDA-MB-231 cells. The results provide a new insight into the biological role of Ganoderma meroterpenoids in TNBC.