Also, the presence of a flavone moiety in compound
1 was indicated by two strong absorption peaks in its
UV spectrum at 275 and 341 nm, respectively. The addition
of a solution of AICl3 shifted the peak at 275 nm
by 37 nm. This shift was indicative of a OH substitution
at the C, position of a flavone ring. Both lH_ and
13C-NMR spectral data for compound 1 were in agreement
with the published spectral values for cirsilineol
(Norr and Wagner, 1992; Youseff and Frahm, 1995) .