Inhibitors of BRD4 protein from the roots of Astilbe grandis stapf ex E.H. Wilson.

A new monoterpene (1) along with eight known compounds were isolated from the roots of Astilbe grandis Stapf ex E.H. Wilson. Their structures were determined by extensive spectroscopic analysis and ECD experiments as (S)-3-(2-hydroxyethyl)-5-(2-methylprop-1-en-1-yl)furan-2(5H)-one (1), caffeic acid (2), mandelic acid (3), sonchifolinin B (4), α-viniferin (5), euscaphic acid (6), cianidanol (7), ß-sitosterol (8), and stigmasterol (9), respectively. Compounds 5 and 6 exhibited inhibitory effects against BRD4 protein with IC50 values of 13.20 and 17.39 µM, respectively. In vitro, compounds 5 and 6 showed moderate cytotoxicity to A549 cells, HCC827 cells and Hela cells with IC50 values ranging from 31.98 to 154.90 µM.