Pulcherrins D–R, potential anti-inflammatory diterpenoids from the roots of Caesalpinia pulcherrima

Bioactivity-guided isolation and purification of the dichloromethane extract from the roots of Caesalpinia pulcherrima yielded 15 new cassane-type diterpenes, named pulcherrins D–R (1–15) together with eight known compounds. The structures of the new metabolites were determined on the basis of spectroscopic analyses including 1D- and 2D-NMR and mass spectroscopy. The anti-inflammatory activity of isolated compounds was investigated with the lipopolysaccharide (LPS)–induced murine macrophage RAW 264.7 cell lines. Compounds 8, 9, 11–15, and 17–23 showed potent NO inhibitory activity.