七叶一枝花中薯蓣皂苷的分离及结构鉴定研究

本文利用高效液相色谱-串联质谱联用方法研究了七叶一枝花中的薯蓣皂苷。实验采用高效液相色谱分离了七叶一枝花中的3种薯蓣皂苷;通过与电喷雾质谱联用获得了这几种化合物的分子量信息;再用MS/MS获得了这几种化合物进一步的结构信息。采用此方法可快速分析鉴定从七叶一枝花中分离得到的薯蓣皂苷。     

高效液相色谱/电喷雾飞行时间质谱分析太子参中环肽类化合物

采用高效液相色谱/电喷雾飞行时间质谱联用方法(HPLC/ESI-TOFMS)分析太子参中的环肽类化合物。实验采用反相C18色谱柱,二元线性梯度洗脱,分离并检测了太子参中6种环肽类化合物;通过与电喷雾飞行时间质谱联用获得了这几种化合物的准确分子量信息,由于ESI-TOFMS具有高分辨率,能够测定化合物精确的分子质量而不降低灵敏度,对6种环肽类化合物成分进行了定性鉴定。该方法简便、快速、准确。     

人参中皂苷类化合物的HPLC-ESI MS研究

利用高效液相色谱与电喷雾质谱联用技术分析鉴定了人参粗提物中人参皂苷类化合物。实验采用反相C18色谱柱,二元线性梯度洗脱（0．2％的醋酸水溶液和乙腈）,分离并检测了人参中的皂苷类化合物：通过与电喷雾质谱的联用和质谱的源内CID技术获得了其中主要色谱峰相对应化合物的相对分子质量和结构信息。     

高效液相色谱-电喷雾质谱联用法测定人参和西洋参的皂苷类成分

利用高效液相色谱（LC—ELSD）与电喷雾质谱（ESI—MS）联用技术对人参和西洋参中的人参皂苷类成分进行了比较研究。通过液相色谱与质谱联用技术获得了相应化合物的分子量信息;利用质谱的源内CID技术获得了相应化合物的结构信息。根据人参皂苷Rf和拟人参皂苷F11两种同分异构体在质谱中的源内CID裂解规律的不同,建立了人参和西洋参药材的LC-ESI-MS简便、准确的鉴别方法。     

高效液相色谱-四极杆飞行时间质谱分析紫甘蓝和羽衣甘蓝中花色苷

应用高效液相色谱-电喷雾/四极杆飞行时间串联质谱联用技术分析了紫甘蓝和羽衣甘蓝中的花色苷成分.选用Agilent TC-C18色谱柱(250 mm×4.6 mm×5 μm),二元线性梯度洗脱,柱后流出液采用电喷雾四极杆飞行时间质谱的正、负离子模式进行检测.根据一级质谱的分子离子和二级质谱碎片离子,获得化合物的准确分子量...     

高效液相色谱-电喷雾质谱法测定枳壳中黄酮苷类化合物

利用高效液相色谱与电喷雾质谱联用技术研究了枳壳中的黄酮苷类化合物.实验采用反相C18色谱柱,二元线性梯度洗脱,分离并检测了枳壳中的6种黄酮苷类化合物;它们分别是新圣草苷(neoeriocitrin)、异柚皮苷(isonaringin)、柚皮苷(naringin)、橙皮苷(hesperidin)、新橙皮苷(neohesperidin)和新枸橘苷(neoponcirin);通过与电喷雾质谱联用获得了这6种黄酮苷的准分子离子峰([M+H]+)及分子加钠峰([M+Na]+),利用质谱的碰撞诱导解离技术获得了碎片裂解信息.通过这此质谱信息并结合文献,对这6种化合物进行了结构鉴定.     

高效液相色谱-电喷雾质谱法测定枳壳中黄酮苷类化合物

利用高效液相色谱与电喷雾质谱联用技术研究了枳壳中的黄酮苷类化合物。实验采用反相C18色谱柱，二元线性梯度洗脱，分离并检测了枳壳中的6种黄酮苷类化合物；它们分别是新圣草苷（neoeriocitrin）、异柚皮苷（isonaringin）、柚皮苷（naringin）、橙皮苷（hesperidin）、新橙皮苷（neohesperidin）和新枸橘苷（neoponcirin）；通过与电喷雾质谱联用获得了这6种黄酮苷的准分子离子峰（[M＋H]^＋）及分子加钠峰（[M＋Na]^＋），利用质谱的碰撞诱导解离技术获得了碎片裂解信息。通过这此质谱信息并结合文献，对这6种化合物进行了结构鉴定。     

山茱萸炮制过程中环烯醚萜苷类成分的质谱研究

利用高效液相色谱-电喷雾多级串联质谱(HPLC-ESI-MSn)联用技术, 对传统中药山茱萸炮制过程中环烯醚萜苷类成分的变化进行了研究. 采用反相C18色谱柱, 二元线性梯度洗脱, 分离并获得了山茱萸中7个环烯醚萜苷类化合物. 并通过电喷雾一级质谱获得了上述7种化合物的分子量信息, 利用电喷雾质谱的源内碰撞诱导解离技术, 获得了该类化合物在负离子模式下的碎裂特征, 在此基础上, 对其进行了结构鉴定和含量分析. 首次发现了差向异构体7α-乙氧基莫诺苷和7β-乙氧基莫诺苷化合物. 研究结果表明, 当采用HPLC-ESI-MS法分析山茱萸环烯醚萜苷类化合物时, 通过色谱保留时间色谱峰面积和质谱特征两方面信息能够提供更加准确可靠的定性定量结果.     

朝鲜淫羊藿中黄酮类化合物的高效液相色谱与电喷雾质谱联用研究

利用高效液相色谱与电喷雾质谱联用技术研究了朝鲜淫羊藿中的黄酮类化合物。实验采用反相C18色谱柱，二元线性梯度洗脱，分离并检测了朝鲜淫羊藿中的6种黄酮类化合物；通过与电喷雾质谱联用获得了这几种化合物的分子量信息，利用质谱的源内碰撞诱导解离技术对这几种化合物进行了结构鉴定。     

高效液相色谱-质谱法快速鉴定复方毛冬青冲剂中三萜皂苷活性成分

建立了高效液相色谱-质谱法(HPLC-MS)快速鉴定复方毛冬青冲剂中三萜皂苷活性成分的方法.以甲醇为萃取剂超声萃取复方毛冬青冲剂30 min.采用高效液相色谱-离子阱质谱(HPLC-IT-MS)和高效液相色谱-飞行时间质谱(HPLC-TOF-MS)对萃取液进行分析,选用Agilent Zorbax Eclipse XDB C18色谱柱(250 mm×4.6 mm, 5 μm),以水(含0.1 %甲酸)-乙腈为流动相进行梯度洗脱,柱后流出液采用电喷雾离子阱质谱(ESI-IT-MS)和电喷雾飞行时间质谱(ESI-TOF-MS)的正、负离子模式进行检测.检测结果经离子阱一级质谱(IT-MS1)、离子阱二级质谱(IT-MS2)和分析时间质谱(TOF-MS)信息分析,并与相关文献报道进行比较,鉴定出1种三萜酸和8种三萜皂苷成分,并推测了其它3种可能的三萜皂苷化学成分,通过对照品对比分析,三萜酸确证为Ilexgenin A,其中一种三萜皂苷确证为Ilexsaponin A1.本方法无需对照品即可快速有效地鉴定出复方毛冬青冲剂中的三萜皂苷活性成分,为建立冲剂的质量标准提供了依据.     

ESI-QqTOF-MS/MS and APCI-IT-MS/MS analysis of steroid saponins from the rhizomes of Dioscorea panthaica

Using high-resolution quadrupole time-of-flight mass spectrometry along with an electrospray ionization source (ESI-QqTOF-MS), accurate molecular weights of 13 steroid saponins extracted from the rhizomes of Dioscorea panthaica were acquired and the corresponding molecular formulae obtained. In order to elucidate the fragmentation pathways of steroid saponins in D. panthaica, 10 authentic samples were investigated using ESI-QqTOF-MS/MS. In addition, atmospheric pressure chemical ionization mass spectrometry combined with ion trap tandem mass spectrometry (APCI-IT-MS/MS) was used to analyze the structures of 13 steroid saponins in D. panthaica. Through the analysis of their tandem mass data, diagnostic fragment ions of the spirostanol and furostanol steroid saponins in D. panthaica were detected as m/z 271.2056 and 253.1951. In addition, four pairs of isomers were detected and the possible structures of four unknown steroid saponins in D. panthaica speculated. ESI-TOF and APCI-MS(n) have proved to be effective tools for research on fragmentation mechanism of steroid saponins and the rapid determination of native steroid saponins in extract mixture, thereby avoiding tedious derivation and separation steps.     

Identification and structural characterisation of triterpene saponins from the root of Ardisia mamillata Hance by HPLC-ESI-QTOF-MS/MS

Triterpene saponins in medicinal plants attract scientific attentions for their structural diversity and significant bioactivities. In this work, a high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS) method is used to rapidly separate and identify triterpene saponins from the extract of Ardisia mamillata Hance (AMH). In the full scan mass spectrum, the accurate determination of molecular formula is obtained by the predominant ion [M + HCOO]^? in negative ion mode. As a result, 30 triterpene saponins are identified or tentatively identified in the plant extract. Of these, 17 triterpene saponins are new compounds. In conclusion, the HPLC-ESI-QTOF-MS/MS is an efficient technique to separate and identify triterpene saponins in complex matrices of medicinal plant.     

Cellular uptake and photocytotoxicity of glycoconjugated chlorins in HeLa cells

Eight 5,10,15,20-tetrakis[3- or 4-(beta-D-glycopyranosyloxy)phenyl]chlorins were synthesized by means of the Whitlock method with diimide reduction and purified by reversed-phase thin layer chromatography (RP-TLC). All compounds were characterized by (1)H NMR spectroscopy, electron-spray ionization time-of-flight mass spectrometry (ESI-TOF MS), and UV-Vis spectroscopy. ESI-TOF MS could detect the 2H difference in molecular weight between a glycoconjugated chlorin and its corresponding porphyrin (i.e., 5,10,15,20-tetrakis[3- or 4-(beta-D-glycopyranosyloxy)phenyl]porphyrin). The cellular uptake of the eight chlorins was evaluated in HeLa cells. All glycoconjugated chlorins showed higher cellular uptake than tetraphenylporphyrin tetrasulfonic acid (TPPS), and 5,10,15,20-tetrakis[3-(beta-D-xylopyranosyloxy)phenyl]chlorin showed 50-fold higher uptake than TPPS. The photocytotoxicity of 5,10,15,20-tetrakis[3-(beta-D-glucopyranosyloxy)phenyl]chlorin, 5,10,15,20-tetrakis[3-(beta-D-xylopyranosyloxy)phenyl]chlorin and TPPS towards HeLa cells was examined at the concentration of 2x10(-7) M (mol/dm(3)). These photosensitizers had no cytotoxicity in the dark, but their photocytotoxicity decreased in the order of 5,10,15,20-tetrakis[3-(beta-D-glucopyranosyloxy)phenyl]chlorin>5,10,15,20-tetrakis[3-(beta-D-xylopyranosyloxy)phenyl]chlorin>TPPS. The results indicate that the photocytotoxicity is not related simply to cellular uptake.     

高效液相色谱-电喷雾银离子诱导电离飞行时间质谱定性分析高沸点多环芳烃

建立了高效液相色谱-电喷雾飞行时间质谱联用技术快速鉴别高沸点多环芳烃的方法。多环芳烃经色谱柱分离后,通过柱后添加AgNO3溶液诱导其在电喷雾离子源中电离,生成多环芳烃[M]+及其复合[M+Ag]+和[2M+Ag]+特征离子,根据所获得的各特征离子的精确分子量和分子式,可实现多环芳烃类化合物的快速鉴别。将本方法用于美国环保局(USEPA)规定的16种优先控制多环芳烃及原油中多环芳烃类化合物的分析鉴别,结果表明,四环以上的PAHs质谱信号良好,说明本方法适用于四环以上的高分子量、高沸点多环芳烃类化合物的分析鉴别。     

Determination of four major saponins in the seeds of Aesculus chinensis Bunge using accelerated solvent extraction followed by high-performance liquid chromatography and electrospray-time of flight mass spectrometry

A new method based on accelerated solvent extraction (ASE) followed by a reliable high-performance liquid chromatography-diode array detector (HPLC-DAD) and positive ion electrospray-time of flight mass spectrometry (ESI-TOF/MS) analysis has been developed for the characterization and quantification of four major saponins in extracts of the seeds of Aesculus chinensis Bunge (Semen Aesculi). The saponins escin Ia, escin Ib, isoescin Ia and isoescin Ib were extracted from seeds of A. chinesis Bunge via ASE, and the operational parameters of ASE were optimized, such as extraction solvent, extraction temperature, static extraction time and extraction cycles. The optimized procedure employed 70% MeOH as extraction solvent, 120 °C of extraction temperature, 7 min of static extraction time, 60% flush volume and the extraction recoveries of the four compounds were nearly to 100% for two cycles. The HPLC conditions are as follows: SinoChrom ODS BP C₁₈ (4.6 mm × 200 mm, 5 μm) column, acetonitrile and 0.10% phosphoric acid solution as mobile phase, flow rate is 1.0 mL min⁻¹, detection length of UV is 203 nm, injection volume is 10 μL. The results indicated that the developed HPLC method is simple, sensitive and reliable for the determination of four major saponins in seeds of A. chinesis Bunge with a good linearity (r² > 0.9994), precision (relative standard deviation (R.S.D.) <1.5%) and the recovery ranges of 95.2-97.3%. The limits of detection (LOD) of the four compounds were in the range of 0.40-0.75 μg mL⁻¹. This assay can be readily utilized as a quality control method for Semen Aesculi and other related medicinal plants.     

Rapid characterization of triterpene saponins from Conyza blinii by liquid chromatography coupled with mass spectrometry

Conyza blinii Le'vl is a medicinal herb used for the treatment of inflammation in Chinese folk medicine. Its major bioactive constituents are triterpene saponins, most of which contain 6–8 sugar residues. In this report, electrospray ionization tandem mass spectrometry fragmentation behaviors of bisdesmosidic triterpene saponins (conyzasaponin A, B, and C) were studied in both positive and negative ion modes with an ion‐trap mass spectrometer. In full scan mass spectrometry, these saponins gave predominant [M–H]^? and [M+Na]⁺ ions, which determined the molecular weights. In tandem mass spectrometry (MSⁿ, n = 2–4), the [M–H]^? and [M+Na]⁺ ions yielded fragments [Y_0α–H]^? and [B_α+Na]⁺, which were diagnostic for the structures of the triterpene skeleton and sugar chains. The structural elucidation was approved by accurate mass data using IT‐TOF‐MS. An interpretation guideline based on MSⁿ (n = 2–4) diagnostic ions was proposed in order to elucidate the chemical structures of unknown triterpene saponins in C. blinii extract. The saponins in C. blinii were separated by liquid chromatography with a methanol/acetonitrile/water solvent system, and then analyzed by ion‐trap and IT‐TOF mass spectrometers. Based on the interpretation guideline, a total of 35 triterpenoid saponins were tentatively identified. Among them, 15 saponins had been previously reported, and the other 20 saponins were reported from Conyza species for the first time. This study indicates that LC/MS is a powerful technology for the rapid characterization of complicated saponins in herbal extracts. Copyright © 2010 John Wiley & Sons, Ltd.     

Structural determination of saponins extracted from starfish by fast atom bombardment collision-induced dissociation mass spectrometry.

Three saponins were extracted and isolated from starfish by reversed-phase high performance liquid chromatography (HPLC), and analyzed by fast atom bombardment mass spectrometry (FAB-MS). Their molecular weight information could be obtained by the presence of abundant [M+Na]+ ions and weak [M+H]+ ions in FAB-MS spectra. Moreover, high resolution mass measurements of their [M+Na]+ ions were performed at the resolution of 10000 to elucidate the element composition of extracted saponins. The collision-induced dissociation (CID) of sodium-adducted molecules [M+Na]+ yielded diverse product ions via dissociated processes. In the collision-induced dissociation (CID)-MS/MS analysis of [M+Na]+ ion, the sulfate-containing saponins produced characteristic ions such as SO4Na+, [NaHSO4+Na]+, [M+Na-sugar]+ and [M+Na-2sugar]+ ions, whereas the sulfate-free compound showed characteristic ions produced by cleavage of sugar moiety and side chain of aglycone. The fragmentation patterns could provide information on the linkage position of sugar groups in aglycone and sulfate groups.     

Direct qualitative analysis of triacylglycerols by electrospray mass spectrometry using a linear ion trap

Triacylglycerols (TAGs) isolated from a biological sample provide a challenge for mass spectrometric analysis because of the complexity of naturally occurring TAGs, which may contain different fatty acyl substituents resulting in a large number of molecular species having the identical elemental composition. We have investigated the use of mass spectrometry to obtain unambiguous information as to the individual TAG molecular species present in a complex mixture of triacylglycerols using a linear ion trap mass spectrometer. Ammonium adducts of TAGs, [M+NH4]+, were generated by electrospray ionization, which permitted the molecular weight of each TAG molecular species to be determined. The mechanisms involved in the decomposition of the [M+NH4]+ and subsequent fragment ions were investigated using deuterium labeling, MS/MS, and MS3 experiments. Collision induced decomposition of [M+NH4]+ ions resulted in the neutral loss of NH3 and an acyl side-chain (as a carboxylic acid) to generate a diacyl product ion. MS/MS data were used to identify each acyl group present for a given [M+NH4]+ ion, and this information could be combined with molecular weight data to identify possible TAG molecular species present in a biological extract. Subsequent MS3 experiments on the resultant diacyl product ions, which gave rise to acylium (RCO+) and related ions, enabled unambiguous TAG molecular assignments. These strategies of MS, MS/MS, and MS3 experiments were applied to identify components within a complex mixture of neutral lipids extracted from RAW 264.7 cells.     

Structural characterization and identification of iridoid glycosides,saponins, phenolic acids and flavonoids in Flos Lonicerae Japonicae by a fast liquid chromatography method with diode‐array detection and time‐of‐flight mass spectrometry

A fast liquid chromatography method with diode‐array detection (DAD) and time‐of‐flight mass spectrometry (TOF‐MS) has been developed for analysis of constituents in Flos Lonicerae Japonicae (FLJ), a traditional Chinese medicine derived from the flower bud of Lonicera japonica. The chromatographic analytical time decreased to 25 min without sacrificing resolution using a column packed with 1.8‐µm porous particles (4.6 × 50 mm), three times faster than the performance of conventional 5.0‐µm columns (4.6 × 150 mm). Four major groups of compounds previously isolated from FLJ were structurally characterized by DAD‐TOF‐MS: iridoid glycosides showed maximum UV absorption at 240 nm; phenolic acids at 217, 242, and 326 nm; flavonoids at 255 and 355 nm; while saponins had no absorption. In electrospray ionization (ESI)‐TOF‐MS experiments, elimination of a glucose unit (162 Da), and successive losses of H₂O, CH₃OH and CO, were generally observed in iridoid glycosides; saponins were characterized by a series of identical aglycone ions; phenolic acids typically generated a base peak at [M–H–caffeoyl]^? by loss of a caffeic acid unit (162 Da) and several marked quinic acid moiety ions; cleavage of the glycosidic bond (loss of 162 or 308 Da), subsequent losses of H₂O, CO, RDA and C‐ring fragmentation were the most possible fragmentation pathways for flavonoids. By accurate mass measurements within 4 ppm error for each molecular ion and subsequent fragment ions, as well as the ‘full mass spectral’ information of TOF‐MS, a total of 41 compounds including 13 iridoid glycosides, 11 phenolic acids, 7 saponins, and 10 flavonoids were identified in a methanolic extract of FLJ. Copyright © 2009 John Wiley & Sons, Ltd.     

Characterization of spirostanol saponins in Solanum torvum by high-performance liquid chromatography/evaporative light scattering detector/electrospray ionization with multi-stage tandem mass spectrometry

High-performance liquid chromatography with an evaporative light scattering detector and electrospray ionization multistage tandem mass spectrometry (HPLC/ELSD/ESI-MS(n)) was used to identify spirostanol saponins in a saponin extract of Solanum torvum. The fragmentation behavior of saponins was studied using ESI-MS(1-3) in positive ion mode. The MS(n) spectra of the [M+H](+) ions provide structural information including aglycone type and the nature and sequence of sugars. The use of ELSD allowed the profiling of the nonchromophore-containing saponins in this plant. The MS analysis established in this study with known saponins was successfully applied to tentatively identify two new siprostanol glycosides, neosolaspigenin 6-O-beta-D-quinovopyranoside and solagenin 6-O-[beta-D-xylopyranosyl-(1 --> 3)-O-beta-D-quinovopyranoside].