云南甘草中齐墩果烷型五环三萜化合物的NMR谱的研究

本文研究了云南甘草皂甙元(glyyunnansapogenin)等oleanane类化合物的核磁共振谱。运用PBB,INEPT,DEPT方法,并结合化学位移值规律归属了这些化合物的¹³C-NMR信号。总结出用角甲基的化学位移植范围判定角甲基的取代位置的方法,分析了角甲基被氧取代后对环的化学位移值的影响。按类似olean-12-en,18α-H方式考虑,归属了oleana-11,13(18)-diene化合物的¹³C-NMR信号。讨论了具30→18β内酯或2929→18α内酯类化合物的核磁谱规律。另外,还发现了DE环上有1个OAC取代时,与其偕碳质子的化学位移值规律。

NMR STUDIES OF PENTACYCLIC TRITERPENOIDS OF OLEANANE TYPE FROM GLYCYRRHIZA YUNNANSIS

The NMR spectra of oleanane type triterpenoids, glyyunnansapogenins (I-IX) have been investigated. The assignments of the ¹³C-NMR signals have been made by using PBB, INEPT, DEPT methods and the known chemical shift rules. It was found that the oxygenated substitute at the angular methyl group can be easily recognized by inspecting the chemical shifts of the angular methyl groups, and the effects of oxygenated substitutes to the rings are also analyzed. In the assignments of the ¹³C-NMR signals of olean-11,13 (18)-diene compounds, the junction between D and E ring is considered to be the same as that of 18α-H olean-12-en, compounds. The known chemical shift rules used to the olean-12-en, 11-oxo, 30(or 29) →18β (or 18α) lactone arc also discussed. Another regular chemical shift for the oleanane compounds with one OAc group subsitituted in D or E ring has also been found.