Rapid characterization and identification of non-volatile constituents in Pogostemonis Herba by UPLC-Q-TOF-MS combined with UNIFI and an in-house library / 中国中药杂志

This study aimed to characterize and identify the non-volatile components in Pogostemonis Herba by using ultra-perfor-mance liquid chromatography-quadrupole-time of flight-mass spectrometry(UPLC-Q-TOF-MS) combined with UNIFI and an in-house library. The chemical components in 50% methanol extract of Pogostemonis Herba were detected by UPLC-Q-TOF-MS in both positive and negative MS~E continuum modes. Then, the MS data were processed in UNIFI combined with an in-house library to automatically characterize the metabolites. Based on the multiple adduct ions, exact mass, diagnostic fragment ions, and peak intensity of compounds and the fragmentation pathways and retention behaviors of reference substances, the structures identified by UNIFI were further verified and those of the unidentified compounds were tentatively elucidated. A total of 120 compound structures were identified or tentatively identified, including flavonoids, phenylpropanoids, phenolic acids, terpenes, fatty acids, alkaloids, and phenylethanoid glycosides. Sixteen of them were accurately identified by comparison with reference substances, and 53 compounds were reported the first time for Pogostemonis Herba. This study systematically characterized and identified the non-volatile compounds in Pogostemonis Herba for the first time. The findings provide a scientific basis for revealing the pharmacodynamic material basis, establishing a quality control system, and developing products of Pogostemonis Herba.

Identification of metabolites in different parts of Juandan Baihe (Lilium lancifolium) by UPLC-Q-TOF-MS and their hypoglycemic activities / 数字中医药（英文）

Objective @#To identify the main components in the extracts of different parts of Juandan Baihe (Lilium lancifolium) by ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) technology and investigate their hypoglycemic activities.@*Methods@#The MS fragmentation pathways of the main types of compounds in Juandan Baihe (Lilium lancifolium) were studied, and the main components in the extracts were systematically identified using MS fragmentation pathways combined with MS mining technology. Based on the hyperglycemia male mouse model [specific pathogen free (SPF)-grade Kunming mice] induced by streptozotocin (intragastric administration of 80 mg/kg for 3 d), the hypoglycemic effects of extracts of Juandan Baihe (Lilium lancifolium) roots, stems, corms, leaves, and flowers were evaluated by measuring the changes of blood glucose, daily water consumption, daily food intake, and body weight.@*Result@#The MS fragmentation pathways of regalosides, dioscins, phenylpropanoids, flavonoids, and chlorogenic acids in Juandan Baihe (Lilium lancifolium) were clarified, and a mining method for compounds in this plant was constructed. A total of 58 compounds, including 6 chlorogenic acids, 14 regalosides, 13 phenylpropanoids, 5 flavonoids, and 20 dioscins, were identified from the roots, stems, corms, leaves, and flowers of Juandan Baihe (Lilium lancifolium). Among them, 30 compounds were reported for the first time from this plant. The root and corm extracts demonstrated significant hypoglycemic activities by reducing blood glucose levels from 23.76 ± 1.21 and 24.29 ± 1.35 mmol/L to 17.21 ± 1.23 and 18.78 ± 1.49 mmol/L, respectively (P < 0.05). The roots and corms extracts could also attenuate the symptoms of polydipsia (P < 0.01), polyphagia (P < 0.05), and weight loss caused by diabetes.@*Conclusion@#This study clarifies that the roots of Juandan Baihe (Lilium lancifolium) are rich in regalosides and dioscins for the first time, and have significant hypoglycemic activities, providing the foundation for the comprehensive utilization of this plant and the development of hypoglycemic drugs.

Study on fragmentation pathways of three ginkgolides by mass spectrometry / 中国中药杂志

The fragmentation pathways of the three ginkgolides (ginkgolides A, ginkgolides B, ginkgolides C) have been studied with high resolution and high mass accuracy using quadrupole time-of-flight mass spectrometry in negative ion mode in this paper. The results indicate that the three ginkgolides have similar fragmentation pathways, including four kinds of common cleavage pathways and one common characteristic ion. In high quality regions, the typical fragmentation pathways of the three ginkgolides are lactone ring opening with continuous loss of CO, CO₂,and loss of H₂O. In low quality regions, the common characteristic fragment ion of the three ginkgolides at 72.993 6 is formed by C rings cleavage. Also, the common fragment ions of ginkgolides A and ginkgolides B at 141.018 8, 125.023 8, 113.024 0, 97.029 1 are formed by A rings cleavage. The study of fragmentation pathways could be adopted for the structural identification of the ginkgolides and their metabolites.

Rapid screening and identification of sesquiterpene lactones in Kudiezi injection based on high-performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry / 中国天然药物

Sesquiterpene lactones are considered as the major active compounds in Kudiezi injection in virtue of their special structures and activities. Herein, an analytical method was developed for rapid screening and identification of sesquiterpene lactones in Kudiezi injection using high-performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry (HPLC-LTQ-Orbitrap) in negative ion mode. First, two sesquiterpene lactone reference standards were analyzed to obtain their characteristic ESI-MS/MS fragmentation patterns. Second, based on extracted ion chromatography (EIC) data-mining method and characteristic fragmentation pathways analysis, sesquiterpene lactones in Kudiezi injection were rapidly screened and identified. Finally, an important parameter Clog P was adopted to discriminate the isomers of sesquiterpene lactones. As a result, 50 sesquiterpene lactones were characterized, including 9 sesquiterpene lactone aglycones, 39 sesquiterpene lactone glycosides, and 2 amino acid-sesquiterpene lactone conjugates. Among them, 13 compounds were tentatively identified as new compounds. The results demonstrated that the established method would be a rapid, effective analytical tool for screening and identification of sesquiterpene lactones in the complex system of natural medicines.

Rapid screening and identification of sesquiterpene lactones in Kudiezi injection based on high-performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry / 中国天然药物

Sesquiterpene lactones are considered as the major active compounds in Kudiezi injection in virtue of their special structures and activities. Herein, an analytical method was developed for rapid screening and identification of sesquiterpene lactones in Kudiezi injection using high-performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry (HPLC-LTQ-Orbitrap) in negative ion mode. First, two sesquiterpene lactone reference standards were analyzed to obtain their characteristic ESI-MS/MS fragmentation patterns. Second, based on extracted ion chromatography (EIC) data-mining method and characteristic fragmentation pathways analysis, sesquiterpene lactones in Kudiezi injection were rapidly screened and identified. Finally, an important parameter Clog P was adopted to discriminate the isomers of sesquiterpene lactones. As a result, 50 sesquiterpene lactones were characterized, including 9 sesquiterpene lactone aglycones, 39 sesquiterpene lactone glycosides, and 2 amino acid-sesquiterpene lactone conjugates. Among them, 13 compounds were tentatively identified as new compounds. The results demonstrated that the established method would be a rapid, effective analytical tool for screening and identification of sesquiterpene lactones in the complex system of natural medicines.

Analysis of bacitracin and its related substances by liquid chromatography tandem mass spectrometry / 药物分析学报

A suitable liquid chromatography quadrupole time-of-flight mass spectrometric (LC–Q-TOF–MS) method was developed for separation and characterization of related substances in bacitracin test drug. The separation was performed on LiChrospher RP-18 column using methanol as mobile phase A and 0.2% ammonium acetate buffer solution as mobile phase B in gradient elution. A total of 12 related substances were detected through high resolution mass spectrometric determination in a positive electrospray ionization mode. They were identified as co-existing active components and degradation products of bacitracin through the analysis and elucidation of both the protonated parents and the product ions of all the related substances and their fragmentation pathways were also proposed.

Fragmentation pathways of five characteristic diterpenoid compounds in Isodon coetsa / 中草药

Objective To study the fragmentation pathways of five 7,20-cyclo-ent-kaurane diterpenoid compounds (rabdocoetsin B, megathyrin B, rabdocoetsin A, enanderianin N, and megathyrin A) in Isodon coetsa. Methods The samples were analyzed by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS2). According to the fragment in MS2 of five compounds, the possible fragmentation pathways of these diterpenoid compounds were inducted. Results In negative mode, the typical fragmentation pathways of these compounds in high-quality areas were mainly loss of substituents on C-1, C-7, and the oxygen bridge on C-20. The fragmentation pathways were different as a result of the difference of the substituents on C-1. The fragment, which in medium and low quality areas, suggested that fracture order of these compounds were A ring to B and then to C ring. Conclusion The study on fragmentation pathways contributed to the structural identification of 7,20-cyclo-ent-kaurane diterpenoid compounds.

Fragmentation pathways of six aconitine alkaloids using HPLC-Q-TOF-MS technology / 中草药

Objective: To study the fragmentation pathways of six aconitine-type alkaloids (aconitine, hypaconitine, mesaconitine, benzoylaconitine, benzoylhypaconitine, and benzoylmesaconitine) in mass spectra (MS). Methods: The samples were analyzed by liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). Results: In positive mode, The typical fragmentation pathways of the six aconitine-type alkaloids were mainly continuous loss of CH3OH and H2O. The characteristic fragmentation pathway of diester-diterpene type aconitine was losing an acetic acid molecule from C-8 position; However this fragmentation could not be observed in MS of mono-ester aconitine alkaloids. Conclusion: The study on fragmentation pathways could be adopted for the structural identification of the six aconitine-type alkaloids.

Simultaneous Determination of 20 Anti-Obesity Drugs Illegally Added in Weight-loss Functional Foods by Matrix Solid Phase Dispersion-High Performance Liquid Chromatography Tandem Mass Spectrometry / 分析化学

An analytical method based on high performance liquid chromatography tandem mass spectrometry has been developed for the simultaneous determination of 20 anti-obesity drugs ( fenfluramine, phenylpropanolamine, sibutramine, sertraline, rimonabant, bupropion, citalopram, fluoxetine, benfluorex, topiramate, zonisamide, caffeine, phenolphthalein, emodin, indapamide, bumetanide, torasemide, triamterene, orlistat, phenformin). that were extracted from various weight-loss functional foods by ethanol-acetone(7:3, V/V)and purified by primary secondary amine (PSA) and octadecyltrimethoxysilane(ODS) under ultrasonication. The analysis was carried out on HPLC-MS /MS by electrospray ionization using multiple reaction monitoring after the chromatographic separation on Waters Atlantis T3 (3 μm, 150 mm × 2. 1 mm) column. Identification was achieved by the retention time and the ion ratio, quantification was done by the external standard method. The limits of detection for the appetite suppressants were 0. 05-3. 0 mg/kg. The mean recoveries at the three spiked levels were 67 . 1%-101 . 4%, with the intra-day precision less than 10%and the inter-day precision less than 15%. The method is reliable, accurate, reproducible and suitable for the determination of the anti-obesity drugs in different weight-loss functional foods.

ESI/MS Study on Fragmentation Pathways of Schisandrin B by the Discovery Studio / 世界科学技术-中医药现代化

This study was aimed to find the fragmentation pathways of Schisandrin B using the Discovery Studio by electrospray ionization mass spectrometry (ESI-MSn). The first and multi-stage mass spectrum diagrams were obtained. The results showed that mass spectrometry fragments of Schisandrin B was analyzed under the positive mode, the cracking rings are mainly occurred, and free radicals such as H2O, -CH3 and -OCH3 were lost. It was concluded that this study enriched the mass spectral decomposition, and provided basis for the study on chemical constituents of lignan compounds.

Simultaneous Determination of 11 Appetite Suppressants in Weight-loss Functional Foods by Accelerated Solvent Extraction- High Performance Liquid Chromatography Tandem Mass Spectrometry / 分析化学

An analytical method based on high performance liquid chromatography tandem mass spectrometry has been developed for the determination of 11 appetite suppressants (fenfluramine,phenylpropanolamine,sibutramine,sertraline,rimonabant,bupropion,citalopram,fluoxetine,benfluorex,topiramate,zoni-samide). Various weight-loss functional foods were extracted under accelerated solvent extraction and separated on Waters Atlantis T3( 150 mm×2.1 mm,3μm) column. The analysis was carried out on HPLC-MS/MS by electrospray ionization using multiple reaction monitoring. Identification was achieved by ihe retention time and the ion ratio,quantification was done by the external standard curves. The limits of detection for the appetite suppressants were 0.05-4.0 mg/kg. The mean recoveries at the three spiked levels(low,middle,high) were 78.3% - 103. 6% ,with the intra-day precision less than 12% and the inter-day precision less than 15%. The method is reliable,sensitive,reproducible,and adapts to the determination of the appetite suppressants in different weight-loss functional foods.

Mechanisms of catalpol and jasminoidin by electrospray ionization mass spectrometry / 中草药

Objective To study the collision-induced dissociation fragmentation pathways of the jasminoidin and catalpol in ESI-Msn. Methods The samples were studied by using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-Msn) both in positive and negative. Results The collision-induced dissociation fragmentation pathways of both compounds were described. In the spectrum of two compounds, the loss of glucose residue and whole glucose were observed in positive mode, while only the loss of glucose residue could be observed in negative mode. Furthermore, we found that as the effect of the substituting groups, the fragment ions of jasminoidin were more in positive mode and those of catalpol were more in negative mode. Conclusion Conclusion The established method could be used for the sensitive and rapid identification of this kind of iridoid glycosides。