Bioassay-guided isolation of hepatoprotective lignans from <i>Vernonia cinerea</i>: DeepSAT-driven structural elucidation and predictive mechanistic insights against drug-induced liver injury

Three new dibenzylbutane lignans, vernolignans A-C (1-3), along with three known compounds (4-6), were isolated from <i>Vernonia cinerea</i> through a bioactivity-guided isolation process. The planar structures of the new compounds (1-3) were elucidated through comprehensive analysis of HR-ESI-MS and 1D/2D NMR data, with the assistance of AI-based structure annotation tool DeepSAT. The absolute configurations of 1-3 were determined by comparing the experimental and calculated ECD spectra. Compounds 2 and 3 exhibited significant improvements in cell viability and attenuated acetaminophen-induced alanine aminotransferase levels in murine hepatocytes at 20 μM. Bioinformatics analysis and molecular docking suggested that BRAF might be a potential target for these lignans.