HRSIMS of jasnudifloside C (3) established the composition
as C43H60O22. Its 1H and 13C NMR spectral features
(Tables 1 and 2) clearly demonstrated the presence of a
triol (9) moiety and two oleoside units, of which one
contained a methylated carboxyl group. This assumption
was supported by hydrolysis of 3, which afforded oleoside
and triol 9. The pattern of ester linkages was determined
by a combination of 1H-1H COSY, HMQC, and HMBC
experiments, which allowed assignment of the signals from
H-7¢¢ and H-10¢¢ as well as the signals of the carbonyls C-7a,
C-7b, C-11a, and C-11b. The HMBC experiments with 3
showed strong interactions between H-7¢¢ and C-7a (ä
173.36), between OMe and C-11a (ä 168.62), and between
H-10¢¢ and C-11b (ä 168.78). Accordingly, the structure of
jasnudifloside C is 3.