色散管理孤子传输特性分析

色散管理孤子光波系统的色散图周期由具有正负色散值的两段光纤组成，并且在系统中周期性放置集中放大器及滤波器装置。采用变分法获得了描述此种系统性能的常微分方程组，并利用这组方程数值研究了各种参量对孤子传输性能的影响。研究结果表明，虽然从整体趋势上看，当要求色散管理孤子有较好的稳定性时，应适当降低系统的色散管理强度，但在一定条件下，调整光纤放大器的位置以及正负色散光纤的色散差值，可同时获得相对较大的色散管理强度和好的孤子稳定性；总体来讲，集总放大器的位置会对孤子传输的稳定性、色散管理孤子的能量增强因子、脉冲最佳

有机质谱裂解规律及智能解析方法研究

本学位论文分为四个部分，第一部分报道了用串联质谱快速分析合成药物中的微量杂质成分以及分析中药材中的化学成分。第二部分报道了通过质谱和串联质谱发现并合成新型的PdPincer 催化剂，同时对其活性进行测试。第三部分为串联质谱自动解析软件的设计及应用。第四部分概述了应用在质谱中的各种碎裂方式。 第一部分首先总结了5-溴粉防己碱及其类似物的裂解规律，并以此为根据推测出2 个微量杂质的结构。随后针对无患子（Sapindus mukurossi Gatren.）中的皂苷成分，由ESI-QTOF 得到各个皂苷成份的高分辨质量数据进而得到其分子式，然后利用ESI-IT 电喷雾串联质谱对无患子总皂苷中各皂苷成分的结构进行进一步的鉴定。进而以同样的方式，先通过ESI-QTOF 得到黄山药（Dioscoreapanthaica）总皂苷中各个组分化合物的分子式，然后对已有的薯蓣皂苷标准品做串联质谱分析，以得到该类化合物的裂解规律并给出解析该类化合物的流程图。在此利用计算化学的方法讨论了离子的丰度与裂解活化能之间的关系。然后应用APCI-MS/MS 方法探讨了四对同分异构体和几个已知的化合物，并最后用液质联用对其进行确认，同时还给出了4 个未知化合物的可能结构。 第二部分报道通过质谱和串联质谱发现并合成新型的PdPincer 催化剂，同时对其活性进行测试。钯催化的交联反应是有机合成中C-C 键形成的最有效的方法，且硫脲是一类对空气和水都稳定的化合物，因此我们设计并合成了一系列的硫脲钯催化剂并得到了很好的催化活性。我们在对其中一类环状双硫脲化合物进行质谱实验的时候，在正离子模式下发现了反常的[M.H]+，通过串联质谱进一步确定了它是一种新型的PdPincer 结构。我们将其合成出来并通过X-ray 衍射实验确定了它的结构。同时测定其催化活性并与未形成pincer 的类似物进行比较发现该类化合物具有较宽的底物适用性。 第三部分为串联质谱自动解析软件的设计及应用。通过前面两部分的启示，独立设计开发了AuMass（1.0）。其算法是：先通过查找特殊的碎片离子，中性丢失或碎片离子质量差来确定某类化合物的骨架结构，然后利用该类化合物的自动解析流程来对其周边取代基进行确认。通过它快速地对白芍中的化学成分进行解析，并对未知的化合物进行了推测。为了增加它的解析能力，我又对其它类型的化合物裂解规律进行总结，并给出了自动解析流程。实践证明该软件具有相当好的应用价值。 第四部分综述了应用在质谱上的各类母离子的碎裂技术。这里包括了碰撞诱导裂解（CID）、光诱导碎裂（LID）、电子捕获裂解/电子转移裂解（ECD/ETD）、红外多光子解离（IRMPD）、黑体辐射解离（BIRD）和PQD 裂解技术。 This dissertation consists of four chapters. The first chapter reports the rapidanalysis of trace impurities from synthetical medicine and analysis of the chemicalconstitutents from Chinese herb medicines. The second chapter elaborates the studieson the discorvery and synthesis of new type of Pd Pincer catalyst by using MS andtandem MS together with the testing of its catalyst activity. The third chapter dwellson the designation and development of automatic tandem mass spectrometry analysissoftware. The last chapter presents a review on the dissociation technique of massspectrometry. The first chapter reports the rapid analysis of trace impurities from synthesismedicine and analysis of the chemical constitutents from Chinese herb medicines. The fission mechanism of 5-bromotetrandrine was obtained by analysis of the dissociationpathways of major product, by using which the possible structure of the two traceimpurties was assumed. There are lots of saponins in Sapindus mukurossi. Except forthe good spumescence and decontamination，it possesses the bioactivity of antigenand antitch. First of all, the high resolution mass information was obtained by ESI-QTOF. Hence the possible molecular formulars were acquired too. Then weconducted the further detection of the structures of its saponins by using ESI-ITtechnology. In the same manner, first the molecular formulars of every constituentfrom Dioscorea panthaica in total saponins were obtained by ESI-QTOF, and thenacquired the fission mechanism of this type of compounds by tandem massexperiment on a series of known and available saponins. In the same time, theanalysis flowchart was concluded. Here the relationship between the ion intensity andthe corresponding dissiociation activation energy was studied by computer chemistry.Then the four pairs of isomers were differentiated by APCI-MS/MS, as well as thecharacterization of known and unknown compounds. The assumption was confirmed by HPLC-MS/MS. Among them the possible structures of four unknown saponinswas presented. The second part was discovery and synthesis of a new type of Pd pincer catalystby MS and tandem MS. The coupling reaction catalyzed by Pd is the most effectivemethod in C-C formation in organic synthesis. Apart from that, thiourea is type ofcompounds that are stable to atmosphere and moisture. Hence we designed a series ofPd thiourea catalysts. Some of them show the excellent catalyst activity. The abnormalparent ion [M.H]+ was founded in positive ESI mode when we conduct some massspectrometry experiments on the bicyclical thiourea Pd complex. The structure wasproposed by mass and tandem mass spectrometry. Because it was a new type of pincer,we want to test its catalyst activity. So the Pd pincer was synthesized and the detailstructure was obtained by x-ray experiment. It shows the more fitness in catalysis ofSuzuki reaction by comparison with the analogue. The third chapter dwells on the design and development of automatic tandemmass spectrometry analysis software. Inspired by the former two chapters, theAuMass (version 1.0) was developed. Its algorithm is: first check the diagnostic ion,diagnostic neutral loss or diagnostic ions mass intervals in database to find out whatthe analyst’s skeleton belongs to, then identify the peripheral functional group by thecorresponding analysis flowchart. The chemical constituents of Paeonia lactiflorawere identified rapidly by using AuMass. To increase the analysis ability, the othertypes of compounds from Chinese herbs was concluded. Actually, the software isproven to have the much valuable application. The last chapter presented the review on the some kinds of fission technique ofmass spectrometry. It involves the collision induced dissociation (CID), laser induceddissociation (LID), electron capture dissociation/electron transfer dissociation(ECD/ETD), infrared multiple photons dissiociation, black body irraditiondissociation and PQD fission technique from Finnigan.

Direct characterization of bitter acids in a crude hop extract by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

The applicability of on-line coupling of reversed-phase high-performance liquid chromatography to atmospheric pressure ionization tandem mass spectrometry for the separation and characterization of hop acids mixture from the crude extract of Humulus lupulus was investigated. The solvent system consisting of acetonitrile-aqueous formic acid was used to give proper separation of the six main hop bitter acids within 30 min. Further structural information about the components was acquired by collision-induced dissociation (CID). On the basis of analyses of the fragmentation patterns of the major alpha- and beta-bitter acids respectively, identification of the minor ones was performed using selected reaction monitoring (SRM) with a group of qualitatively relevant selected precursor-product ion transitions for each bitter acid in a single high performance liquid chromatography (HPLC) run. Using this technique, six minor hop acids, including "adprelupulone" observed for the first time in natural resources, were detected along with the six major acids. This hyphenated techniques provides potency for rapid qualitative determination of analogs and homologs in mixtures. (C) 2004 American Society for Mass Spectrometry.

Screening and Structural Characterization of alpha-Glucosidase Inhibitors from Hawthorn Leaf Flavonoids Extract by Ultrafiltration LC-DAD-MSn and SORI-CID FTICR MS

In vitro a-glucosidase inhibition assays and ultrafiltration liquid chromatography with photodiode array detection coupled to electrospray ionization tandem mass spectrometry (ultrafiltration LC-DAD-ESI-MSn) were combined to screen a-glucosidase inhibitors from hawthorn leaf flavonoids extract (HLFE). As a result, four compounds were identified as alpha-glucosidase inhibitors in the HLFE, and their structures were confirmed to be quercetin-3-O-rha-(1-4)-glc-rha and C-glycosylflavones (vitexin-2 ''-O-glucoside, vitexin-2 ''-O-rhamnoside and vitexin) by high-resolution sustained off resonance irradiation collision-induced dissociation (SORI-CID) data obtained by Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS).

Identification of Phenylethanoid Glycosides in Plant Extract of Plantago asiatica L. by Liquid Chromatography-Electrospray Ionization Mass Spectrometry

The present work describes a liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) method for rapid identification of phenylethanoid glycosides in plant extract from Plantago asiatica L. By using a binary mobile phase system consisting of 0.2% acetic acid and acetonitrile under gradient conditions, a good separation was achieved on a reversed-phase C-18 column. The [M-H](-) ions, the molecular weights, and the fragment ions of phenylethanoid glycosides were obtained in the negative ion mode using LC-ESI-MS. The identification of the phenylethanoid glycosides (peaks 1-3) in the extract of P. asiatica L. was based on matching their retention time, the detection of molecular ions, and the fragment ions obtained by collision-induced dissociation (CID) experiments with those of the authentic standards and data reported in the literature.

Analysis on Iridoid Glycosides in Crude and Processed Extracts from Cornus Officinals by Liquid Chromatography-electrospray Ionization Mass Spectrometry

The iridoid glycosides in crude and processed extracts from cornus officinals have been analyzed by high performance liquid chromatography-electrospray ionization mass spectrometry. Samples were analyzed by a reversed-phase C18 column using a binary eluent under gradient conditions. Seven iridoid glycosides could be separated and detected. The [M-H](-) ions of iridoid glycosides in the negative ion mode were observed, which reflect their molecule mass information. An in-source collision induced dissociation (in-source CID) experiment was carried out in order to identify the structures and to measure the contents of iridoid glycosides. The epimers were discovered in the experiment for the first time, namely 7 alpha-O-ethyl-morroniside and 7 beta-O-ethylmorroniside.

Analysis of Saponins from Leaves of Aralia elata by Liquid Chromatography and Multi-stage Tandem Mass Spectrometry

Four saponins were isolated from the leaves of Aralia elata, and established using NMR and other spectroscopic methods, as well as data reported in the literature. Three Aralia saponins from the leaves of Aralia elata sharing the same structures as those isolated from the root bark suggested that the leaves would be a good substitute for the root bark of Aralia elata. These four Aralia saponins were then extensively investigated using complementarily positive and negative electrospray ionization multistage tandem mass spectrometry (ESI-MSn). Two isomers of saponins with different sugar linkages were then successfully differentiated by positive ESI-MSn and verified with different retention times and the collision-induced dissociation (CID) spectra by LC-MS. A simple and effective LC-MS method was thus developed for the rapid identification and screening of these saponins in plant extracts from leaves of Aralia elata.

A study of the non-covalent interaction between flavonoids and DNA triplexes by electrospray ionization mass spectrometry

The binding interactions of 22 flavonoids (9 aglycones and 13 glycosides) with DNA triplexes were investigated using electrospray ionization mass spectrometry (ESI-MS). The results revealed that the hydroxyl positions of aglycones. the locations and numbers of saccharide, as well as the aglycone skeletons play roles in the triplex-binding properties of flavonoids. The presence of 3-OH, or 3'-OH, or replacement of 4'-OH with methoxy group in aglycones decreased the fraction of bound DNA sharply. Flavonoid glycosides exhibit higher binding affinities towards the DNA triplexes than their aglycone counterparts. Glycosylations of flavones at the 8-C position and isoflavones at the 7-O position show higher binding affinities than those on the other positions of ring A of aglycones. Glycosylation with a disaccharide on 0 position of flavonol results in higher binding affinity than that with monosaccharide. Flexibility of the ring B is favorable for its interaction with DNA triplex. According to sustained off-resonance irradiation collision-induced dissociation (SORI-CID) experiments, glycosylation and non-planarity of flavonoid aglycones lead to different dissociation pathways of the flavonoid/triplex complexes.