Discovery of four new malabaricane saponins, malabarosides A-D, from the aerial parts of Dysphania ambrosioides with nitric oxide production inhibitory activity.

The plant Dysphania ambrosioides has long been best known for its traditional use as a medicine to treat worms and other intestinal parasites, as well as for treating wounds. Phytochemical study of the methanol extract of the aerial parts of D. ambrosioides led to the isolation of four undescribed 13α-malabaricane saponins named malabarosides A-D (1-4). Their chemical structures were determined based on extensive spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR spectra. These compounds moderately inhibited nitric oxide (NO) production in lipopolysaccharide activated RAW264.7 cells with IC50 values ranging from 52.6 to 61.0 µM. This is the first malabaricane-type triterpenoid reported from the family Amaranthaceae.