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.
Ginkgolides ; chemistry ; Mass Spectrometry ; Spectrometry, Mass, Electrospray Ionization

OBJECTIVES: To analyze the chemical structure of the interfering substance that affects the result of methamphetamine analysis in wastewater. METHODS: A combination of GC-MS and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was used to analyze the mass spectrum characteristics of the interfering substance that affects the result of methamphetamine analysis and to infer its possible structure. Liquid chromatography-triple quadrupole-mass spectrometry (LC-TQ-MS) was used to confirm the control material. RESULTS: Using LC-QTOF-MS in positive electrospray ionization (ESI⁺) mode, the mass-to-charge ratio (m/z) of quasi-molecular ion in the MS¹ mass spectrometry of interfering substance was identical to that of methamphetamine, indicating that the interfering substance was probably an isomer of methamphetamine. The MS² mass spectra obtained at three collision energies of 15 V, 30 V and 45 V were highly similar to methamphetamine, suggesting that the interfering substance contained methylamino and benzyl groups. Further analysis using GC-MS in electron impact (EI) ionization mode showed that the base peak in the mass spectrum of the interfering substance was at m/z 44. The interfering substance was confirmed to be N-methyl-2-phenylpropan-1-amine by compared with the standard reference. CONCLUSIONS The chemical structure of N-methyl-2-phenylpropan-1-amine is highly similar to methamphetamine, which is easy to cause interference for the detection of trace amounts of methamphetamine in wastewater using LC-TQ-MS. Therefore, in the actual analysis, the chromatographic retention time can be used to distinguish between N-methyl-2-phenylpropan-1-amine and methamphetamine.
Methamphetamine ; Wastewater ; Amines ; Gas Chromatography-Mass Spectrometry/methods* ; Mass Spectrometry/methods* ; Spectrometry, Mass, Electrospray Ionization/methods*

Objective To study the identification method for 4'-F-4-methylaminorex （4'-F-4-MAR） in samples without reference substance. Methods Gas chromatography-mass spectrometry （GC-MS）, ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry （UPLC-QTOF-MS）, nuclear magnetic resonance （NMR） and Fourier transform infrared （FTIR） were comprehensively used for the structure identification of 4'-F-4-MAR in samples. Results Under the positive electrospray ionization （ESI⁺） mode, quasi-molecular ion in the first order mass spectrometry of the unknown compound was 195.092 6 and its molecular formula was inferred to be C₁₀H₁₁FN₂O. The fragment ions in the mass spectrometry of the unknown compound were compared with the related fragment ions of 4,4'-dimethylaminorex （4,4'-DMAR） in literature. It was found that the main fragment ions of the unknown compound were all 4 bigger than the corresponding fragment ions of 4,4'-DMAR. Therefore, the unknown compound was inferred to be a 4,4'-DMAR analogue with a methyl substituted by a fluorine in the benzene ring. The equivalent protons at δ=7.30 and δ=7.06 in ¹H-nuclear magnetic resonance （¹H-NMR） spectra and the characteristic spin-spin coupling constants （¹J_C-F=245.2 Hz, ²J_C-F=21.3 Hz, ³J_C-F=8.1 Hz） for ¹³C-¹⁹F interactions in carbon spectra, further proved that the fluorine substituted methyl at the para-position of the benzene ring. Finally, the unknown compound was determined as 4'-F-4-MAR. Conclusion A method that comprehensively used the identification materials 4'-F-4-MAR in GC-MS, UPLC-QTOF-MS, NMR and FTIR is established and the fragmentation mechanism of fragmentation ions of 4'-F-4-MAR created under the two modes -- electron impact （EI） and electrospray ionization under collision induced dissociation （ESI-CID） is deduced. The information will assist forensic science laboratories in identifying this compound or other substances with similar structure in their case work.
Aminorex ; Chromatography, High Pressure Liquid ; Gas Chromatography-Mass Spectrometry ; Mass Spectrometry ; Nitroimidazoles ; Spectrometry, Mass, Electrospray Ionization

To elucidate further sequence selectivity and nature of the binding of anticancer drugs to DNA, the interaction between anticancer drugs, which are minor groove ligands (distamycin A, DM and netropsin, NP) and intercalator (mitoxantrone, MT), and DNA were studied by electrospray ionization mass spectrometry. The 2 : 1 specific complex of DM and AT-rich DNA were observed principally, while only 1 : 1 specific complex of NP and AT-rich DNA were observed. MT specifically binds to GC-rich DNA. In addition, DM binds to DNA containing 5 A/T bases minor groove almost in a 2 : 1 mode and does not bind to DNA containing 3 A/T bases minor groove. NP binds most strongly to DNA containing 4 A/T bases minor groove. The 1 : 1 specific complex of MT and 6-mer DNA was also observed. The result of competitive binding experiment shows that DM binds more strongly to AT-rich DNA than NP does. These results provide bases for investigating the mechanism of interaction between the drugs and DNA and for improving the structure of target drug.
Antineoplastic Agents ; chemistry ; DNA ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; methods

A high performance liquid chromatography with a diode array detector combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry(HPLC-DAD-ESI-IT-TOF-MS~n, HPLC-MS~n) method was established for qualitative analysis of the chemical components of ethyl acetate extract from Sinopodophylli Fructus. The analysis was performed on a Kromasil 100-5 C_(18)(4.6 mm×250 mm, 5 μm) column, with a mobile phase consisted of 0.1% formic acid(A) and acetonitrile(B) for gradient at a flow rate of 1.0 mL·min~(-1). Electrospray ionization ion trap time-of-flight multistage mass spectrometry was applied for qualitative analysis under positive and negative ion modes. With use of reference substance, characteristic fragmentation and their HR-MS data, 102 components were identified, including 67 flavonoids and 35 lignans. Among them, 45 compounds were reported in Sinopodophylli Fructus for the first time and 19 compounds were identified as new compounds. PharmMapper was used to predict the bioactivity of compounds that were first reported in Sinopodophylli Fructus, and 20 compounds of them were identified to have potential anticancer activity. The results showed that there were many isomers in the ethyl acetate extract of Folium Nelumbinis, and a total of 19 groups of isomers were found. Among them, C_(21)H_(20)O_8 had the highest number of isomers(18 compounds), all of which were α-peltatin or its isomers; C_(21)H_(20)O_7 ranked second, with 10 compounds, all of which were 8-prenylquercetin-3-methyl ether or its isomers. In conclusion, an HPLC-MS~n method was established for qualitative analysis of the ethyl acetate extract(with anti-breast cancer activity) from Sinopodophylli Fructus in this study, which will provide the evidence for clarifying pharmacological active ingredients of the ethyl acetate extract from Sinopodophylli Fructus against breast cancer.
Acetates ; Chromatography, High Pressure Liquid ; Fruit ; Spectrometry, Mass, Electrospray Ionization

Phospholipids are key components of cellular membrane and signaling. Among cellular phospholipids, phosphoinositides, phosphorylated derivatives of phosphatidylinositol are important as a participant in essential metabolic processes in animals. However, due to its low abundance in cells and tissues, it is difficult to identify the composition of phosphoinositides. Recent advances in mass spectrometric techniques, combined with established separation methods, have allowed the rapid and sensitive detection and quantification of a variety of lipid species including phosphoinositides. In this mini review, we briefly introduce progress in profiling of cellular phosphoinositides using mass spectrometry. We also summarize current progress of matrices development for the analysis of cellular phospholipids using matrix-assisted laser desorption/ionization mass spectrometry. The phosphoinositides profiling and phospholipids imaging will help us to understand how they function in a biological system and will provide a powerful tool for elucidating the mechanism of diseases such as diabetes, cancer and neurodegenerative diseases. The investigation of cellular phospholipids including phosphoinositides using electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry will suggest new insights on human diseases, and on clinical application through drug development of lipid related diseases.
Animals ; Humans ; Mass Spectrometry/*methods ; Phosphatidylinositols/*metabolism ; Phospholipids/*metabolism ; Spectrometry, Mass, Electrospray Ionization ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

OBJECTIVETo investigate the monoterpene glycosides in Paeonia lactflora by UPLC-MS/MS.

METHODAn Acquity UPLC BEH C18 column (2.1 mm x 50 mm) with 1.7 microm particle size was used. The mobile phase was composed of acetonitrile and 0.1% formic acid in gradient mode. The flow rate was 0.4 mL x min and the chromatographic run time was 9 min for one run. The mass spectrometer equipped with an eletrospray ion source in negative ion mode.

RESULTSTotally six glycosides were analyzed and identified by the established UPLC-MS/MS method.

CONCLUSIONThe method was rapid, sensitive, and extremely useful for rapid identification of glycosides in P. lactiflora.

An HPLC-DAD-MS/MS method was developed for rapid analysis and identification of degradation products of buagafuran. Buagafuran and degradation products were separated on a Zorbax C8 column (5 microm, 4.6 mm x 150 mm) using acetonitrile-water (78 : 22) as mobile phase. The elutes were detected with diode array detector and tandem mass spectrometer via electrospray ionization source in positive ion mode. According to analysis of the retention time, UV spectra and MS, MS/MS data, combined with the possible degradation reaction of buagafuran, the structures of main degradation products were inferred. The results showed that six main degradation products were oxidation or peroxidation productions of buagafuran. Degradation product A was a double bond epoxidation product of buagafuran, degradation products B, C, D and E were the further oxidation products of degradation product A, degradation product F was a peroxidation product of buagafuran. The results indicated that the established method was effective in the rapid identification of the degradation products of buagafuran.
Chromatography, High Pressure Liquid ; methods ; Sesquiterpenes ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; methods ; Tandem Mass Spectrometry ; methods

OBJECTIVETo discuss mass spectrum characterization of five valepotriates including 'monoene' type (didrovaltrate), 'diene' type (valtrate, acevaltrate) and 'four-olefinic' type (baldrinal and homobaldrinal) by electrospray ionization tandem mass spectrometry (ESI-MS(n)).

METHODThis study was carried out on the basis of electrospray ionization tandem mass spectrometric method and analysis of multistage fragments.

RESULTThe fragmentation patterns and structural assignment of 'monoene' type, 'diene' type and 'four-olefinic' type valepotriates in ESI-MSn under positive mode were summarized.

CONCLUSIONThe compounds have a strong pyrolysis rules and it can provide reference date for valepotriates in rapid structural identification, quantitative analysis and pharmacokinetic study.

To analyze and identify the chemical components in Xingbei Zhike Keli by using ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS/MS). The analysis was performed on Agilent Zorbax SB-C₁₈(4.6 mm×250 mm, 5 μm) column, with methanol-0.08% formic acid solution (including 0.1% ammonium formate) as the mobile phase for gradient elution. The flow rate was 1 mL·min⁻¹ and column temperature was 30 °C. The MS spectrum was acquired in both negative and positive ion modes by using electron spray ionization (ESI). These components were further analyzed based on accurate m/z, secondary fragmentation and other information combined with reference substance and literature data. As a result, 87 compounds were successfully identified and predicted, including alkaloids, flavonoids, coumarins and saponins, of which 23 compounds were verified by comparing with reference substances. These results provide reference for the quality control of Xingbei Zhike Keli, and lay the foundation for elucidating their effective components and mechanism of action.
Alkaloids ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; Flavonoids ; Spectrometry, Mass, Electrospray Ionization ; Tandem Mass Spectrometry