Prenylated Bibenzyls from the Chinese Liverwort and Their Mitochondria-Derived Paraptotic Cytotoxic Activities.

Nine new prenylated bibenzyls, radstrictins A-I (-), and 11 known congeners were obtained from the Chinese liverwort . Their structures were identified by analysis of HRMS, NMR, and electronic circular dichroism data. Radstrictins A-F (-) were isolated as a racemate or scalemic mixtures. All the isolated compounds were subjected to cytotoxicity assessment. Methyl 2,4-dihydroxy-3-(3-methyl-2-butenyl)-6-phenethylbenzoate () exhibited significant activity against human lung cancer cell lines A549 and NCI-H1299 with IC values of 6.0 and 5.1 μM, respectively. Further research revealed that cell death triggered by occurred via mitochondria-derived paraptosis.