Comprehensive Characterization of Lignans from <i>Forsythia viridissima</i> by UHPLC-ESI-QTOF-MS, and Their NO Inhibitory Effects on RAW 264.7 Cells

• Main Authors: Jungmoo Huh, Chang-Min Lee, Seoyoung Lee, Soeun Kim, Namki Cho, Young-Chang Cho
• Format: Article
• Language: English
• Published: MDPI AG 2019-07-01
• Series: Molecules
• Subjects: <i>Forsythia viridissima</i>; lignan dimers; lignans; lignan glycosides; LC-MS^e analysis; anti-inflammatory activity; RAW 264.7
• Online Access: https://www.mdpi.com/1420-3049/24/14/2649

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 <i>F. viridissima</i> by UHPLC-ESI-QTOF-MS. Lignan glycosides (<b>1</b> and <b>2</b>), lignans (<b>3</b> and <b>4</b>), and lignan dimers (<b>5</b>&#8722;<b>10</b>) were identified by analysis of their exact masses and MS^e spectra along with the characteristic mass fragmentation patterns and molecular formulas. We further investigated NO inhibitory effects of <i>F. viridissima</i> fractions and their major lignan derivatives to evaluate those anti-inflammatory effects. The methylene chloride fraction of <i>F. viridissima</i> as well as compounds <b>8</b> and <b>10</b> showed potent dose-dependent NO inhibitory effects on RAW 264.7 cells. Corresponding to the NO inhibition by compounds <b>8</b> and <b>10</b>, 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 <i>F. viridissima</i> roots could be potential anti-inflammatory agents and these are related to major lignans including dimeric dibenzylbutyrolactone lignans.