【作者】 陈娟娟；

【导师】 潘远江；

【作者基本信息】 浙江大学 ， 化学， 2009， 博士

【摘要】 液质联用技术(HPLC/ESI-MSn)结合了色谱强大的分离能力与质谱优越的定性功能,具有灵敏度高,分析速度快,样品消耗量少等优点,并能获得丰富结构信息,已成为了一种对药用植物进行在线分析的强有力工具。本论文运用这一技术,成功地对通光藤中的聚氧孕烷糖苷、黑鳗藤中的齐墩果烷型三萜皂角苷、绿爬山虎中的多酚和姜科植物中的有效成分进行了分析研究,主要内容包括以下四个部分。第一部分应用电喷雾串联质谱法系统探讨并归纳了聚氧孕烷糖苷的质谱裂解规律,在此基础上,运用液质联用技术在线快速识别与分析了药用植物通光藤中18个聚氧孕烷糖苷化合物,通过傅立叶变换离子回旋共振质谱(FTICR-MS)离线确定这些化合物的准确元素组成。在这18个化合物中,5个糖苷分别确定为Marsdenoside K, Tencissoside A, B, C和D,2个鉴定为新糖苷结构,其余11个化合物获得了可能结构。论文还利用能量分辨曲线区分了这18个聚氧孕烷糖苷中的五对同分异构体。第二部分应用电喷雾串联质谱法详细分析总结了药用植物黑鳗藤中齐墩果烷型三萜皂角苷的结构特征与它们的质谱裂解途径之间的关系：即当取代基(除羟基外)位于C21上时,糖苷[M+Na]+离子的多级质谱中能产生直接丢失糖链末端残基的碎片；当取代基(除羟基外)与C22相连接时,则末端糖基不会发生丢失。基于这些碎裂机理,运用液质联用技术在线快速识别与鉴定了12个皂角苷,其中有4个皂角苷是首次在该植物中被报道,另有4个皂角苷被鉴定为新结构化合物,运用一维和二维核磁共振技术确证了通过质谱直接分析推测出的4种皂角苷结构。第三部分应用电喷雾串联质谱法研究了药用植物绿爬山虎中具有抗氧化活性的多酚化合物的多级碎裂机理和结构特征之间的关系,提出了这类化合物主要的碎裂途径和特征碎片离子：含有2,3-二氢-1H-茚-4,6-二醇结构的化合物能形成特征碎片68Da(C302),碎片C2H20(42Da)则是从间苯二酚环上丢失产生的。利用液质联用技术快速识别并分析了该植物浸膏中的15个多酚化合物,其中11个为已知化合物,3个为该植物中首次发现,另外1个被推测为新化合物。利用质谱的能量分辨曲线区分了一对非对映异构体,结合LC-DAD-UV技术区分了四对顺反异构体。第四部分采用液质联用技术分析鉴定了姜科植物中的化合物,共分析鉴定了13个微量成分,其中7个化合物结构通过液相保留时间和标准参照物来确认,另外6个化合物结构则是通过多级质谱裂解来确定,在这6个化合物中,2个为已知化合物,4个化合物被推测为新化合物。根据能量分辨曲线成功地区分了4个化合物可能的构型。此外论文还简要介绍了液质联用技术和串联质谱的工作原理,以及该技术在药用植物中的研究进展。更多还原

【Abstract】 High-performance liquid chromatography combined with electrospray ion trap mass spectrometry possesses high separation efficiency and great capability in on-line structural characterization. With the advantages of high sensitivity, relatively short analysis time and low sample amount, HPLC/ESI-MS" has been widely used as a powerful tool in various medicinial plants online analysis. In this dissertation, the liquid chromatography/electrospray tandem mass spectrometry method was developed to identify the following natural compounds:polyoxypregnane glycosides in Marsdenia tenacissima, oleanane-type saponins in Stephanotis mucronata, polyphenol compounds in Parthenocissus laetevirens and compounds in Zingiber cassumunar. The details are listed in the following:Part I A method based on ESI-MS" was established to analyze of the fragmentation behaviors of polyoxypregnane glycosides. Eighteen polyoxypregnane glycosides from the stems of Marsdenia tenacissima were rapidly identified by HPLC/MS". Offline Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) was also performed to assign the accurate elemental compositions. Among these eighteen polyoxypregnane glycosides, five of them are identified as Marsdenoside K, Tencissoside A, B, C and D; two of them are confirmed as novel compounds; and the other eleven compounds’structures are tentatively suggested. Furthermore, five pairs of isomers were also distinguished from these eighteen compounds through breakdown curves.PartⅡThe relationship between the structural characteristics and MSn fragmentation pathways of oleanane-type saponins in the roots of Stephanotis mucronata were investigated by ESI-MS". We found that direct loss of terminal sugar residue from the [M+Na]+ ion was observed, when the substituent (except hydroxyl group) located at C21 position. However, the terminal sugar did not loss from the [M+Na]+ ion, when the substituent (except hydroxyl group) linked to C22 position. Based on these dissociation behaviors, twelve saponins were identified by HPLC/MS". Four of the; saponins were reported in this plant for the first time and four of the saponins were presumed to be new compounds. The structures of four proposed saponins have been identified by 1D and 2D NMR experiments.Part III The relationship between the structural characteristics and MS" fragmentations of polyphenols in the roots and stems of Parthenocissus laetevirens was investigated by ESI-MS". We found that the fragment C3O2 was presented when the compound possessed a 2,3-dihydro-lH-indene-4,6-diol moiety. Meanwhile, the C2H2O fragment (42 Da) was yielded from the resorcinol ring. Finally, fifteen polyphenol compounds were characterized by HPLC/MS". Eleven of them were identified as known compounds. Three polyphenol compounds were extracted from P. laetevirens for the first time. In addition, one compound was thought as a novel one. Furthermore, a pair of stereoisomers was distinguished by breakdown curves, and the trans-, cis-isomers were identified by HPLC/DAD-UV spectra.PartⅣCompounds extracted from rhizomes of Zingiber cassumunar were analyzed by HPLC/MS". In short, thirteen components were identified. Seven known compounds were qualitatively analysized by retention times of reference standards, and the other six compounds were characterized by MS". Two of the six compounds were identified as known compounds, but the other four were assigned as new compounds. Furthermore, breakdown curves were utilized to distinguish the the configurations of four compounds.In addition, the principle of LC/MSn technique and its recent progress in medicinal plants was reviewed in details.更多还原