Chemical Constituents and Anti-inflammatory Principles from the Fruits of Forsythia suspensa

Fifty compounds were isolated from the fruits of Forsythia suspensa, including 13 new compounds characterized as eight new diterpenoids (1–8), three new lignans (9–11), a new iridoid (12), and a new triterpenoid (13). Their structures were established on the basis of spectroscopic and spectrometric analysis. Most of the isolated compounds were examined for their anti-inflammatory activity in vitro. The results showed that several compounds displayed significant inhibition of fMLP/CB-induced superoxide anion generation and elastase release, with IC50 values ranging from 0.6 ± 0.1 to 8.6 ± 0.8 μg/mL and from 0.8 ± 0.3 to 7.3 ± 1.1 μg/mL, respectively.