作者針對文獻關于 ent- kauran- 16 β,17- diol(Ⅰ)碳信號指認有誤的問題,用化學合成方法和 2 D-NMR技術對 的結(jié)構(gòu)進行全面分析和論證,首次歸屬了每個氫質(zhì)子的信號,并再次證實其結(jié)構(gòu)中的 C- 1、C- 7和 C- 14互為顛倒,該研究對 ent- kaurane骨架二萜結(jié)構(gòu)的鑒定有實際意義。

The authors, in their study of the structure of fritillebin A, an ent-kauran diterpenoid dimer, by 2D-NMR, found that one of its hydrolytic product, the ent-kaurane-16β，17-diol (Ⅰ), though, in all respects, were identical with the authentic sample, yet the 2D-NMR, and especially the NOESY showed an error in the attribution of carbon signals, reported in the literature. To further proved the identity of I in their possession, the compound was compared with the product obtained from ent-kaurane by oxidizing with KMnO₄ in argon in the presence of phase transfer catalyst, which proved that the synthetic product was in all respects identical to (Ⅰ) obtained from natural origin. But on attribution of each proton signal, it was found that the chemical shift of C-1, C-7 and C-14 should be 40.3, 42.1 and 37.3 instead of 42.0， 37.2 and 40.4 respectivly as reported in the literature. The authors further noticed that similar errors also appeared in other compounds reported, therefore the correction of these errors may provide some practical significance for the structural elucidation of ent-kaurane diterpenoids.