Triterpenoid saponins from the rhizome of Impatiens pritzellii var. hupehensis

Abstract

• Two new triterpenoid saponins were isolated from Impatiens pritzellii var. hupehensis . • The structures were successfully determined by spectroscopic and chemical methods. • The compounds showed clear proliferative inhibition of T-lymphocyte cells. • These compounds may be the main active constituents in Impatiens pritzellii var. hupehensis against healing rheumatoid arthritis. Two new oleanane-type triterpene glycosides, 3- O - β - d -glucuronopyranosyl -echinocystic acid-28- O - β - d -apiofuranosyl-(1→3)[ O - β - d -xylopyranosyl)(1→4)]- O - α - l -rhamnopyranosyl-(1→2)- β - l -arabinopranoside ( 1 ) and 3- O - β - d -glucurono pyranosyl-echinocystic acid-28- O - β - d -apiofuranosyl-(1→3)[ O - β - d -xylopyranosyl -(1→4)]- O - α - l -rhamnopyranosyl-(1→2)- β - d -xylopyranoside ( 2 ) along with two known compounds impatienoside G ( 3 ) and scaberoside A 2 ( 4 ), were isolated from an n -butanol fraction of the 50 % aqueous ethanol extract of the rhizome of Impatiens pritzellii var . hupehensis . The compounds were separated by silica gel column chromatography and RP-HPLC. Their structures were elucidated through the analysis of 1D and 2D NMR spectra and HRESIMS data. The T-lymphocyte proliferation activity of the isolated terpenoid saponins was evaluated by using the CCK-8 colorimetric method.