This acyl moiety was assumed to be the same as that in euphormisin
M23 on the basis of comparison of 1H and 13C NMR data of 3 with
those of the reported data5 and the observation of HMBC correlations
from H-3′ to C-4′ and C-7′, from H-2 to C-1, C-3, and C-6,
and from H-4 to C-3 and C-5 (Figure 4).