The present study was designed to develop a practical strategy to tackle the problem of lacking standard compounds and limited references for identifying structure-related compounds in Streptocaulon griffithii Hook. f...The present study was designed to develop a practical strategy to tackle the problem of lacking standard compounds and limited references for identifying structure-related compounds in Streptocaulon griffithii Hook. f., especially those in trace concentrations, with a focus on antitumor activity. The cardiac glycosides(CGs)-enriched part was determined using in vitro bioactive assays in three cancer cell lines and then isolated using macroporous resins. The MS and MS/MS data were acquired using a high performance liquid chromatography coupled with hybrid quadrupole-time of flight(HPLC-Q-TOF-MS) system. To acquire data of trace compound in the extract, a multiple segment program was applied to modify the HPLC-Q-TOF-MS method. A mass defect filter(MDF) approach was employed to make a primary MS data filtration. Utilizing a MATLAB program, the redundant peaks obtained by imprecise MDF template calculated with limited references were excluded by fragment ion classification, which was based on the ion occurrence number in the MDF-filtered total ion chromatograms(TIC). Additionally, the complete cleavage pathways of CG aglycones were proposed to assist the structural identification of 29 common fragment ions(CFIs, ion occurrence number ≥ 5) and diagnostic fragment ions(DFIs, ion occurrence number < 5). As a result, 30 CGs were filtered out from the MDF results, among which 23 were identified. This newly developed strategy may provide a rapid and effective tool for identifying structure-related compounds in herbal medicines.展开更多
文摘采用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱(ultra-high performance liquid chromatography-quadrupole/exactive Orbitrap mass spectrometry,UPLC-Q-Exactive Orbitrap MS)和质量亏损过滤技术(mass defect filter,MDF)对三叶青黄酮类化合物进行定性分析。通过查阅文献,确定三叶青黄酮类物质母核作为MDF模板,根据取代基的数目和种类确定MDF的质量范围、质量亏损范围,采用UPLC-Q-Exactive Orbitrap MS采集—MDF-Orbitrap Traditional Chinese Medicine Library(OTCML)数据库检索—Mass Frontier验证的鉴定策略,对三叶青乙醇冷浸液所含的黄酮类物质进行定性分析,共鉴定出41种黄酮类化合物,其中19个为首次发现。该方法对于准确识别三叶青黄酮类化合物,进而科学评价三叶青质量、促进三叶青合理开发具有一定的指导意义。
基金supported by the National Natural Science Foundation of China(Nos.81673567 and 81703382)
文摘The present study was designed to develop a practical strategy to tackle the problem of lacking standard compounds and limited references for identifying structure-related compounds in Streptocaulon griffithii Hook. f., especially those in trace concentrations, with a focus on antitumor activity. The cardiac glycosides(CGs)-enriched part was determined using in vitro bioactive assays in three cancer cell lines and then isolated using macroporous resins. The MS and MS/MS data were acquired using a high performance liquid chromatography coupled with hybrid quadrupole-time of flight(HPLC-Q-TOF-MS) system. To acquire data of trace compound in the extract, a multiple segment program was applied to modify the HPLC-Q-TOF-MS method. A mass defect filter(MDF) approach was employed to make a primary MS data filtration. Utilizing a MATLAB program, the redundant peaks obtained by imprecise MDF template calculated with limited references were excluded by fragment ion classification, which was based on the ion occurrence number in the MDF-filtered total ion chromatograms(TIC). Additionally, the complete cleavage pathways of CG aglycones were proposed to assist the structural identification of 29 common fragment ions(CFIs, ion occurrence number ≥ 5) and diagnostic fragment ions(DFIs, ion occurrence number < 5). As a result, 30 CGs were filtered out from the MDF results, among which 23 were identified. This newly developed strategy may provide a rapid and effective tool for identifying structure-related compounds in herbal medicines.
