3-氧,11α-羟基、Δ12-齐墩果烯及其类似化合物的13C NMR分析

化合物1-8属于近似结构的齐墩果烷型三萜,它们分别为:β-amyrin(1);3-氧,Δ^11,13(18)-齐墩果二烯(2);3β-羟基,Δ^11,13(18)-齐墩果二烯(3);3β,24-二羟基,Δ11,13(18)-齐墩果二烯(4);3,11-二氧,Δ¹²-齐墩果烯(5);3-氧,Δ9^(11),12-齐墩果二烯(6);3-氧,11α-羟基,Δ¹²-齐墩果烯(7);3β,11α-二羟基,Δ¹²-齐墩果烯(8).它们的¹³C NMR化学位移归属已确定,并通过了DEPT谱的验证.按结构特点分为三组:2~4为第一组,1,5,7,8为第二组,6为第三组.本文重点讨论了它们的¹³C NMR化学位移由其结构特点引起的变化,得到了化学位移与结构相关的有意义的结果.

13C NMR ANALYSIS OF 3-OXE,11-HYDROXY-OLEAN-12-ENE AND ITS ANALOGUE

Compounds 1-8 belong to oleanane type triterpenoids with similiar structures, ¹³C NMR spectra of β-amyrin (1); 3-oxo-olean-11,13(18)-diene (2); 3β-hydroxy olean-11,13(18)-diene (3); 3β,24-dihydroxy-olean-11,13(18)-diene (4); 3,11-dioxo-olean-12-ene (5); 3-oxo-olean-9(11),12-diene (6); 3-oxo, 11α-hydroxy-olean-12-ene(7); 3β,11α-dihydroxy-oean-12-ene-(8) were studied, and spectral assignments were carried out. The assignments were checked by their DEPT spectra. They were divided into three guoups, 2-4 in the first guoup; 1,5,7,8 in the second and 6 in the third. This paper investigated and discussed mainly the changes of their ¹³C NMR chemical shift values which were taken place by the structural characterization and substituted groups. Some significant results of chemical shifts in relation to structures were obtained.