Sesquiterpene coumarins from Ferula fukanensis and nitric oxide production inhibitory effects

Six new sesquiterpene coumarin derivatives, 2,3-dihydro-7-hydroxy-2R,3R-dimethyl-2-[4,8-dimethyl-3(E),7-nonadien-6-onyl]furo[3,2-c]coumarin (4), fukanefuromarin A (5), fukanefuromarin B (6), fukanefuromarin C (7), fukanefuromarin D (8), and fukanemarin A (9), were isolated from a 80% aqueous methanol extract of the roots of Ferula fukanensis. The structures were elucidated on the basis of spectral evidence, especially heteronuclear multiple-bond connectivity (HMBC), nuclear Overhauser exchange spectroscopy (NOESY), and high-resolution MS. An extract of F. fukanensis (FFE) and the sesquiterpene coumarin derivatives inhibited nitric oxide (NO) production and inducible NO synthase (iNOS) gene expression by a murine macrophage-like cell line (RAW 264.7), which was activated by lipopolysaccharide (LPS) and recombinant mouse interferon-gamma (IFN-gamma).