采用核磁共振/液相色谱-质谱异相关谱方法开展药用植物草棉活性提取物中多组分的同步结构分析研究

Simultaneous Structural Identification of Constituents in Active Herbal Extract of Gossypium Herbaceam Using Nuclear Magnetic Resonance/Liquid Chromatography-Mass Spectrometry Hetero-Correlation Spectroscopy

基于不完全分离分析策略,建立了NMR/LC-MS异相关谱(NMR/LC-MS HCS)方法对系列混合物样品的LC-MS和NMR谱数据的整合分析,发掘混合物图谱中来自同一组分的LC-MS和NMR谱数据间的内在相关性。以新疆维吾尔民族药用植物草棉(Gossypium herbaceam L.)花瓣的乙醇提取物(AB-8-2)为研究对象,以多通道组合闪式色谱技术为分离手段,不完全分离并获取了组分含量呈连续动态变化的系列混合物,运用NMR/LC-MS HCS方法对提取物中的黄酮苷类成分进行了同步结构分析研究。由于随组分浓度动态变化的多种谱学信号强度间具有强的正相关性,通过NMR/LC-MS HCS图可以获得系列提取物中同一组分的互补性的LC-MS和1H NMR谱数据,包括保留时间(Rt)、质荷比(m/z)和化学位移值(δ)等关键数据。以已解析的关键谱学信号为线索,引入LC-MS/MS谱和二维NMR谱进行综合分析,成功地从AB-8-2中鉴定出12个黄酮醇苷类化合物,其中还包括2组共流出的同分异构体。结果表明:通过该新型分析方法可以在离线的情况下通过"数学联用的方式"实现与在线LC-NMR-MS联用技术相似的分析功能,这种新型谱学分析方法可以简化复杂混合物的分离分析过程,实现结构复杂成分以及多组分无需完全分离的快速同步结构鉴定;尤其对于常规分离条件下难以获得单体的微量成分或极性相近组分群显示出独特的解析能力。

To simplify and accelerate the analytical routes for structure identification of constituents in complex mixture,based on an incomplete separation strategy,MS/NMR hetero-correlation spectroscopy（MS/NMR-HCS） was developed as a new analytical method to discover the intrinsic correlation between LC-MS and NMR data of the same constituent from mixture spectra.The ethanol crude extract of the petals of Gossypium herbaceam was separated into a series of fractions with the concentration of constituent dynamic variation by flash column chromatography.NMR/LC-MS HCS method was applied to identify the flavonol glycosides in these fractions.The complementary spectral information of the same individual constituent in the crude extract was simultaneously obtained from the spectra of mixtures,including retention time（Rt）,mass/charge（m/z） and chemical shift（δ）.And combined the LC-MS/MS and 2D NMR analysis,twelve constituents including two groups of co-eluted isomers were identified successfully.The results demonstrated that NMR/LC-MS HCS combined with the incompleted separation strategy could achieve the similar function of on-line LC-MS-NMR in an off-line mode by such a ＂mathematics hyphenated approach＂.The new analytical strategy has the potential advantages for simplifying and accelerating the analytical routes for structure identification of constituents in complex mixture.Especially,this method is suitable for analysis and identification of minimum-quantity constituents and constituents with similar polarity which are hardly obtained in routine experimental conditions.