The information that H-1''' (δ 3.20) and showed HMBC correlations to C-5 (δ 74.80), C-6 (δ 197.78) and C-10a (δ 164.44) suggested it being adjacent to C-1''' and quaternary carbon C-5 together with the observation of low chemical shift values of C-5 (δ 74.80) which was due to the inductive effect of oxygen, allowed to assign 2"-propanoyl group and hydroxyl group at C-5.