Three New Ionone Glycosides from Rhododendron capitatum Maxim.

Six ionone glycosides ( 1 - 3 and 5 - 7 ), including three new ones, named capitsesqsides A-C ( 1 - 3 ), together with an eudesmane sesquiterpenoid glycoside ( 4 ) and three known triterpenoid saponins ( 8 - 10 ) were isolated from Rhododendron capitatum . The structures of these compounds were determined by extensive spectroscopic techniques (MS, UV, 1D-NMR, and 2D-NMR) and comparison with data reported in the literature. The absolute configurations were determined by comparison of the experimental and theoretically calculated ECD curves and LC-MS analyses after acid hydrolysis and derivatization. The anti-inflammatory activities of these compounds were evaluated in the LPS-induced RAW264.7 cells. Molecular docking demonstrated that 2 has a favorable affinity for NLRP3 and iNOS.