Bioactive Neo-Clerodane Diterpenoids from Baccharis trimera: Identification and Hepatoprotective mechanisms

Using ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) combined with molecular networking, three previously undescribed neoclerodane diterpenoids and 17 known analogues were identified from the neoclerodane diterpenoid-rich fraction of Baccharis trimera. The fragmentation patterns of this compound class in mass spectrometry were also characterized. Four previously undescribed neoclerodane diterpenoids (Compounds 1-4) were subsequently isolated and structurally elucidated as baccharisacetal A, epibaccharisacetal A, baccharisacetal B, and epibaccharisacetal B through multiple chromatographic and spectroscopic techniques. These compounds exhibited significant protective effects against alcohol-induced hepatic injury in LX-2 cells and in a zebrafish model by decreasing malondialdehyde, alanine aminotransferase, and aspartate aminotransferase levels, while increasing superoxide dismutase activity and glutathione content. Computational absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling indicated favorable pharmacokinetic and safety characteristics. Network pharmacology and molecular docking analyses indicated that the PI3K/Akt pathway may mediate the hepatoprotective effects, a mechanism further corroborated by Western blotting.