Two new and three known steroidal saponins were isolated from the fres
h bulbs of Lilium regale and two known saponins from those of L. henry
i. The structures of the new saponins were established by extensive sp
ectral data, hydrolysis and chemical correlation as oxy-3-methylglutar
oyl]-spirost-5-ene-3beta,27-diol a-D-glucopyranosyl-(1-->3)]-beta-D-gl
ucopyranoside and (25S)-spirost-5-ene-3beta,17alpha,27-triol -D-glucop
yranosyl-(1-->4)]-beta-D-glucopyranoside. Inhibitory activity of the s
aponins on cyclic AMP phosphodiesterase was evaluated.