Structurally Diverse Coumarins from Peucedanum praeruptorum and Their Anti-inflammatory Activities via NF-B Signaling Pathway

The phytochemical study of Peucedanum praeruptorum led to the isolation of twenty-five coumarins (1-25). Of which, (+/-) praeruptol A (+/- 1), one pair of previous undescribed seco-coumarin enantiomers were obtained. Their structures were established according to HR-ESI-MS, NMR, X-ray single crystal diffraction analysis, as well as ECD calculation. All compounds were tested for anti-inflammatory activity in the RAW264.7 macrophage model, and eight compounds (7-10, and 13-16) exhibited significant inhibitory effects with IC50 values ranging from 9.48 to 34.66 mu M. Among them, compound 7 showed the strongest inhibitory effect, which significantly suppressed the production of IL-6, IL-1 beta, and TNF-alpha, as well as iNOS and COX-2 in a concentration-dependent manner. Further investigated results showed that compound 7 exerted an anti-inflammatory effect via the NF-kappa B signaling pathway.