Flavone C-glycosides from the flowers of Trollius chinensis and their anti-complementary activity

Abstract

Phytochemical investigation of ethanol extract from the flowers of Trollius chinensis Bunge resulted in the isolation of two new flavone C-glycosides (1–2), along with 10 known compounds (3–12). The structures of the new compounds were established as 6‴-(3-hydroxy-3-methylglutaroyl)-2″-O-β-d-galactopyranosyl orientin (1) and 6‴-(3-hydroxy-3-methylglutaroyl)-2″-O-β-d-galactopyranosyl vitexin (2) on the basis of various spectroscopic analysis (including different 1D and 2D NMR spectroscopies, high-resolution electrospray ionization mass spectrometry) and chemical evidences. Bioassay showed that eight flavonoids inhibited complement activation on the classic pathway in vitro, with their IC₅₀ values ranging from 0.88 to 4.02 mM, which may contribute to the applications of the herb in treatment of acute respiratory distress syndrome, etc.

Keywords:

• Trollius chinensis
• flavanoid
• C-glycoside
• anti-complementary activity

Acknowledgements

The authors are grateful to Prof. Guoqiang Song of Shanghai Institute of Materia Medica, Chinese Academy of Sciences for the NMR measurements, and Prof. Daofeng Chen of School of Pharmacy, Fudan University for the anti-complementary activity assay. This work was financially supported by a project funded by the Program of Improving the Standard of Pharmacopoeia of the People's Republic of China (2015), and by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).