Abstract
A depside derivative, named pericodepside (2), along with the known depside proatranorin III (1), was isolated from the solid cultivation of an Ascochyta rabiei strain that heterologously expresses atr1 and atr2 that are involved in the biosynthesis of atranorin in a fruticose lichen, Stereocaulon alpinum. The structure of 2 was determined by 1D and 2D NMR and MS spectroscopic data. The structure of 2 consisted of a depside-pericosine conjugate, with the depside moiety being identical to that found in 1, suggesting that 1 acted as an intermediate during the formation of 2 through the esterification process. Pericodepside (2) strongly suppressed cell invasion and proliferation by inhibiting epithelial-mesenchymal transition and the transcriptional activities of β-catenin, STAT, and NF-κB in U87 (glioma cancer), MCF-7 (breast cancer), and PC3 (prostate cancer) cell lines.