Undescribed phenanthrene derivatives and tigliane-type diterpenoids from the roots and stems of Baliospermum yui.

In this study, the phytochemical profile of the roots and stems of Baliospermum yui was investigated for the first time, leading to the isolation of thirteen compounds, including four previously undescribed compounds: phenanthrene monomer baliosperol A (1) and heterodimer baliosperol B (2), and two tigliane-type diterpenoids baliospermins D-E (3-4). Their chemical structures were elucidated by 1D/2D NMR spectroscopy, HRESIMS, ECD calculations and GIAO NMR/DP4+ analysis. Compounds 1-12 were assessed in vitro for their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide-induced RAW264.7 cells, and compounds 1, 2 and 5 showed moderate inhibitory activity with IC50 values ranging from 21.83 ± 1.34 to 30.33 ± 1.48 μM. This study not only represents the first systematic chemical investigation of B. yui, but also highlights its potential as a rich source of tigliane-type diterpenoids.