Madl Tobias, Sterk Heinz, Mittelbach Martin, Rechberger Gerald N
Department of Organic and Bioorganic Chemistry, Institute of Chemistry, Karl Franzens University, Graz, Austria.
J Am Soc Mass Spectrom. 2006 Jun;17(6):795-806. doi: 10.1016/j.jasms.2006.02.013. Epub 2006 Apr 17.
A nano-HPLC electrospray ionization multi-stage tandem mass spectrometry (nLC-ESI-MS/MS) approach was applied to a complex crude triterpene saponin extract of Chenopodium quinoa seed coats. In ESI-MS/MS spectra of triterpene saponins, characteristic fragmentation reactions are observed and allow the determination of aglycones, saccharide sequences, compositions, and branching. Fragmentation of aglycones provided further structural information. The chemical complexity of the mixture was resolved by a complete profiling. Eighty-seven triterpene saponins comprising 19 reported and 68 novel components were identified and studied by MS. In addition to four reported, five novel triterpene aglycones were detected and characterized according to their fragmentation reactions in ESI-MS/MS and electron ionization mass spectrometry (EI-MS). As a novelty fragmentation pathways were proposed and analyzed based upon quantum chemical calculations using a hybrid Hartree-Fock density functional method. Accuracy of the assignment procedure was proven by isolation and structure determination of a novel compound. As the relative distribution and composition of saponins varies between different cultivars and soils, the presented strategy allows a rapid and complete analysis of Chenopodium quinoa saponin distribution and composition, and is particularly suitable for quality control and screening of extracts designated for pharmaceutical, agricultural, and industrial applications.
采用纳升高效液相色谱-电喷雾电离多级串联质谱法（nLC-ESI-MS/MS）对藜麦种皮的复杂粗三萜皂苷提取物进行分析。在三萜皂苷的电喷雾电离串联质谱（ESI-MS/MS）图谱中，观察到了特征性裂解反应，这些反应有助于确定苷元、糖序列、组成和分支情况。苷元的裂解提供了更多的结构信息。通过完整的图谱分析解决了混合物的化学复杂性问题。通过质谱鉴定并研究了87种三萜皂苷，其中包括19种已报道的成分和68种新成分。除了4种已报道的三萜苷元外，还根据它们在电喷雾电离串联质谱（ESI-MS/MS）和电子电离质谱（EI-MS）中的裂解反应检测并表征了5种新的三萜苷元。作为一项创新，基于使用混合Hartree-Fock密度泛函方法的量子化学计算提出并分析了裂解途径。通过分离和鉴定一种新化合物证明了归属程序的准确性。由于不同品种和土壤中皂苷的相对分布和组成各不相同，本文提出的策略能够快速、全面地分析藜麦皂苷的分布和组成，特别适用于药物、农业和工业应用提取物的质量控制和筛选。
