Gancochlearols E - I, meroterpenoids from Ganoderma cochlear against COX-2 and triple negative breast cancer cells and the absolute configuration assignment of ganomycin K.

Five new meroterpenoids, gancochlearols E - I (1, 3-6), and one compound ganomycin K (2) were isolated from the fruiting bodies of G. cochlear. Their structures were assigned by 1D and 2D NMR, MS, and CD analysis. Rh2(OCOCF3)4-induced ECD method was used to clarify the absolute configuration of secondary alcohol in 1 and 2. Biochemical evaluation showed that all the isolates significantly inhibit COX-2 enzyme in vitro with the IC50 values range from 1.03 μM to 2.71 μM. Further cellular assay revealed that (+)-3 and (-)-6 could suppress metastatic phenotype of triple-negative breast cancer (TNBC) cells via impeding the epithelial-mesenchymal transition (EMT).