Iridoid glucosides and phenylethanoid glycosides from Plantago major.

• Five iridoid glucosides and five phenylethanoid glycosides were isolated from Plantago major. • Two new compounds, 10-acetylarborescoside (1) and plantainoside G (6) were elucidated. • This is the first report of phenylethanoid glycoside containing a seco -glucose moiety from natural sources. • Their inhibitory effects on NO production in BV2 cells were evaluated. Using various chromatographic separations, five iridoid glucosides (1 ― 5) and five phenylethanoid glycosides (6 ― 10) were isolated from the Plantago major whole plants and included two new compounds: 10-acetylarborescoside (1) and plantainoside G (6). Their structures were elucidated by detailed analysis of 1D and 2D NMR data, HR QTOF MS data, and experimental and calculated ECD data. The isolated compounds exhibited moderate inhibitory effects on NO overproduction in LPS-stimulated BV2 microglial cells, with IC 50 values ranging from 44.2–62.3 μM. [ABSTRACT FROM AUTHOR]