目的正确归属从地胆草中分离得到的两对牻牛儿内酯型的立体异构体即地胆草种内酯(scabertopin)和异地胆草种内酯(isoscabertopin)以及异去氧地胆草内酯(isodeoxyelephantopin)和去氧地胆草内酯(deoxyelephantopin)的1 H NMR谱信号; 方...目的正确归属从地胆草中分离得到的两对牻牛儿内酯型的立体异构体即地胆草种内酯(scabertopin)和异地胆草种内酯(isoscabertopin)以及异去氧地胆草内酯(isodeoxyelephantopin)和去氧地胆草内酯(deoxyelephantopin)的1 H NMR谱信号; 方法利用NOESY技术, 并结合这4个化合物的1 H NMR谱信息.结果地胆草牻牛儿内酯型立体异构体化合物十元环中3位上的两个质子以及9位上的两个质子在1 H NMR谱中的信号位置都是相反的.结论分析两对立体异构体的NOESY谱差异, 可以对其1 H NMR谱中3位和9位亚甲基的质子信号进行正确归属.展开更多
A new compound was isolated from Helichrysum arenarium(L.) Moench and Phyllostachys nigra vear.hnouis(Bean) Stepf ex Rendle respectively at the same time by the column chromatography on silica gel,Sephadex LH-20 and e...A new compound was isolated from Helichrysum arenarium(L.) Moench and Phyllostachys nigra vear.hnouis(Bean) Stepf ex Rendle respectively at the same time by the column chromatography on silica gel,Sephadex LH-20 and elucidated as 6,7-dimethoxy-4-hydroxy-1-naphthoic acid by the physico-chemcial characters and spectroscopic methods(UV,IR,1D,2D-NMR,ESI-MS).展开更多
文摘目的正确归属从地胆草中分离得到的两对牻牛儿内酯型的立体异构体即地胆草种内酯(scabertopin)和异地胆草种内酯(isoscabertopin)以及异去氧地胆草内酯(isodeoxyelephantopin)和去氧地胆草内酯(deoxyelephantopin)的1 H NMR谱信号; 方法利用NOESY技术, 并结合这4个化合物的1 H NMR谱信息.结果地胆草牻牛儿内酯型立体异构体化合物十元环中3位上的两个质子以及9位上的两个质子在1 H NMR谱中的信号位置都是相反的.结论分析两对立体异构体的NOESY谱差异, 可以对其1 H NMR谱中3位和9位亚甲基的质子信号进行正确归属.
文摘A new compound was isolated from Helichrysum arenarium(L.) Moench and Phyllostachys nigra vear.hnouis(Bean) Stepf ex Rendle respectively at the same time by the column chromatography on silica gel,Sephadex LH-20 and elucidated as 6,7-dimethoxy-4-hydroxy-1-naphthoic acid by the physico-chemcial characters and spectroscopic methods(UV,IR,1D,2D-NMR,ESI-MS).