Two new spirotrifuranocoumarins, rivulotririns A and B (I and 2), were isol
ated from the underground part of Pleurospermum rivulorun. They are charact
erized as two stereoisomers having a different configuration at the C-2 pos
ition resulting from the condensation of two heraclenol and one isogosferol
units, respectively, on the basis of spectral analysis.