Prospective clinical trial, DEFI 2005: Does an AED algorithm with more CPR impact out-of-hospital cardiac arrest prognosis?
详细信息查看全文 | 推荐本文 |
摘要
The liquid chromatography/electrospray tandem mass spectrometry method was developed for analyses and characterization of oleanane-type saponins in the roots of Stephanotis mucronata. Collision-induced dissociation have been performed in order to elucidate the degradation pathways for the [M+Na]+ ions and their predominant product ions. The following characteristic fragmentation was observed from the title saponins: when the substituent (except hydroxyl group) located at C21 position, direct loss of terminal sugar residue from the [M+Na]+ ion was observed; when the substituent (except hydroxyl group) linked to C22 position, the loss of the terminal sugar cannot occur. To further confirm the structures, offline Fourier transform ion cyclotron resonance tandem mass spectrometry (FTICR-MSn) was performed. The structures of four proposed saponins have been identified by 1D and 2D NMR experiments. In this study, 12 saponins were identified. Among them, to our knowledge, four saponins were reported in this plant for the first time and four saponins were presumed to be new compounds. Hence, the described method has wide applicability to rapidly screen and provide structural information of oleanane-type saponins in crude materials.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700