Five new compounds from Hosta plantaginea flowers and their anti-inflammatory activities.

Five new compounds hostines A-E (1-5), together with eighteen known compounds (6-23), were obtained from the flowers of Hosta plantaginea (Lam.) Aschers, a traditional folk herbal medicine widely used in Mongolian. The structures of the undescribed compounds were determined by using detailed spectroscopic (1D/2D NMR) and HR-ESI-MS data analysis. The biological evaluation revealed that hostine C (3), hostine D (4), hostine E (5), stellarine (16), and phenethyl-O-β-d-glucopuranoside (19) possessed the significant anti-inflammatory activities, these compounds significantly inhibited the NO release of RAW 264.7 cells induced by LPS. The possible mechanism of NO inhibition of new bioactive compounds was also investigated using molecular docking, which revealed the interactions of bioactive compounds with the iNOS protein.