A new chlorine-containing iridoid glycoside from Plantago maxima.

A phytochemical investigation on the whole plant of Plantago maxima Juss. ex Jacq led to the isolation of a new and rare chlorinated iridoid glycoside named plantomoside (1), along with three known compounds, geniposidic acid (2), 10-deoxygeniposidic acid (3), and viteoid II (4). The structure of 1 was determined through 1 D and 2 D NMR spectroscopic data analysis, HR-ESI-MS, and acid hydrolysis.