Triterpenoid saponins with antifeedant activities from stem bark of Catunaregam spinosa (Rubiaceae) against Plutella xylostella (Plutellidae).

Seven triterpenoid saponins, including four new compounds, catunarosides A-D (1-4), and three known compounds, swartziatrioside (5), aralia-saponin V (6), araliasaponin IV (7) were isolated from the stem bark of Catunaregam spinosa, a Chinese mangrove associate. Their structures were elucidated on the basis of their spectral data and hydrolysis experiments. The antifeedant activities of compounds 1-7 against Plutella xylostella were also evaluated.