Secobutanolides Isolated from Lindera obtusiloba Stem and Their Anti-Inflammatory Activity

In this study, a new secobutanolide, named secosubamolide B (3), along with three previously known secobutanolides (1, 2, and 4), were successfully isolated from a methanol extract of the stem of Lindera obtusiloba. The chemical structures of these compounds were elucidated through the analysis of spectroscopic data, and then compared with the existing literature to confirm their identities. Furthermore, the anti-inflammatory effect of these isolated compounds on bone marrow-derived dendritic cells stimulated by lipopolysaccharide (LPS) was evaluated. Compounds 1–3 showed the significant suppression of LPS-triggered IL-6 and IL-12 p40 production, with IC₅₀ values between 1.8 and 24.1 µM. These findings may provide a scientific foundation for developing anti-inflammatory agents from L. obtusiloba.