Comprehensive Characterization of Lignans from by UHPLC-ESI-QTOF-MS, and Their NO Inhibitory Effects on RAW 264.7 Cells.

Lignans are known to be an important class of phenylpropanoid secondary metabolites. In the course of our studies on the chemodiversity of lignans, the necessity arose to develop a method for the fast detection and identification of bioactive lignan subclasses. In this study, we detected 10 lignan derivatives of different extracts of by UHPLC-ESI-QTOF-MS. Lignan glycosides ( and ), lignans ( and ), and lignan dimers (-) were identified by analysis of their exact masses and MS spectra along with the characteristic mass fragmentation patterns and molecular formulas. We further investigated NO inhibitory effects of fractions and their major lignan derivatives to evaluate those anti-inflammatory effects. The methylene chloride fraction of as well as compounds and showed potent dose-dependent NO inhibitory effects on RAW 264.7 cells. Corresponding to the NO inhibition by compounds and , lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) expression was notably reduced by both compounds. Our combined data with the bioactive results and the component analysis by UHPLC-ESI-QTOF-MS suggest that the methylene chloride fraction of roots could be potential anti-inflammatory agents and these are related to major lignans including dimeric dibenzylbutyrolactone lignans.