Two new sesquiterpenes named liguducin-A (1) and -B (4) were isolated from
a Chinese medicinal plant, the dried roots of Ligularia duciformis, togethe
r with four known sesquiterpenes, 4 alpha,10 beta-dihydroxy-1 beta,5 alpha-
H-guai-6-ene (2), 4 alpha-hydroxy-1 beta,5 alpha,11 alpha-H-guai-9-en-12,8
alpha-olide (3), 1 beta-hydroxyeudesm-4,11-dien-3-one (5) and 1 beta,6 alph
a-dihydroxyeudesm-4(15)-ene (6). On the basis of the spectral evidence, the
ir structures were determined.