A new triterpenoid saponins, raddeanoside R19 （1） was isolated from the rhizome of Anemone raddeana Regel. The effects of raddeanoside R119 on superoxide generation in human neutrophil were evaluated. The compound suppressed the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine （fMLP）, phorbol 12-myristate 13-acetate （PMA） and arachidonic acid （AA） in a different concentration-dependent manner.
