Fragmentation Patterns of Phenolic C-Glycosides in Mass Spectrometry Analysis.

BACKGROUND: Many phenolic C-glycosides possess nutritional benefits and pharmacological efficacies. However, the MS/MS fragmentation pattern of phenolic C-glycosides analysis is understudied. This paper aims to determine the MS/MS fragmentation patterns of phenolic C-glycosides. METHOD: Ten compounds with different sugar moieties, aglycones, and substitutes were analyzed to determine the impact of these structural features on MS/MS fragmentation using UPLC-QTOF-MS analysis. RESULTS: The results showed that water loss followed by RDA reaction and alpha cleavage in the C-C bonded sugar moieties are the major fragmentation pathways. Additionally, the sugar cleavage was not affected by the skeleton and the substitute of the aglycones. These results suggested that the fragmentation patterns of phenolic C-glycosides differ from those in the O-glycosides, where the O-C glycosidic bond is the most cleavage-liable bond in MS/MS analysis. CONCLUSIONS: These MS/MS fragmentation patterns can be used for the identification of C-glycosides from dietary components and herbal medicine as well as developing robust methods using MRM methods to quantify C-glycosides.

Gas chromatography properties and mass spectrometry fragmentation of anabolic androgenic steroids in doping control.

Aim: This study aimed to investigate the gas chromatographic properties and mass spectrometric fragmentations of anabolic androgenic steroids (AASs) after trimethylsilylated derivatization. Materials & methods: A total of 113 AASs were analyzed through gas chromatography-mass spectrometry in the full-scan mode. Results: New fragmentation pathways yielding m/z 129, 143 and 169 ions were analyzed. Based on the characteristics of the A-ring, seven classes of drugs were identified and analyzed. Conclusion: The fragmentation pathway of a new classification of 4-en-3-hydroxyl was reported for the first time. The relationship between the chemical structures of AASs and their retention time, along with their molecular ion peak abundance, was also reported herein for the first time.

[Chemical constituents in different parts of Ixeris sonchifolia based on UPLC-LTQ-Orbitrap-MS~n].

The chemical constituents in stem leaf, root, and flower of Ixeris sonchifolia were identified by the ultra performance li-quid chromatography coupled with linear ion trap quadrupole-orbitrap mass spectrometry(UPLC-LTQ-Orbitrap-MS~n). The separation was performed on an Acquity UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 µm) with a mobile phase of water(containing 0.1% formic acid, A)-acetonitrile(B) with gradient elution. With electrospray ionization source, the data of 70% methanol extract from stem leaf, root and flower of I. sonchifolia were collected by high-resolution full-scan Fourier transform spectroscopy, data dependent acquisition, precursor ion scan, and selected ion monitoring in the negative and positive ion modes. The compounds were identified based on accurate molecular weight, retention time, fragment ions, comparison with reference standard, Clog P and references. A total of 131 compounds were identified from the 70% methanol extract of I. sonchifolia, including nucleosides, flavonoids, organic acids, terpenoids, and phenylpropanoids, and 119, 110, and 126 compounds were identified from the stem leaf, root and flower of I. sonchifolia, respectively. In addition, isorhamnetin, isorhamnetin-7-O-sambubioside and caffeylshikimic acid were discovered from I. sonchifolia for the first time. This study comprehensively analyzed and compared the chemical constituents in different parts of I. sonchifolia, which facilitated the discovery of effective substances and the development and application of medicinal material resources of I. sonchifolia.

Chemical constituents in different parts of Ixeris sonchifolia based on UPLC-LTQ-Orbitrap-MS~n / 中国中药杂志

The chemical constituents in stem leaf, root, and flower of Ixeris sonchifolia were identified by the ultra performance li-quid chromatography coupled with linear ion trap quadrupole-orbitrap mass spectrometry(UPLC-LTQ-Orbitrap-MS~n). The separation was performed on an Acquity UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 μm) with a mobile phase of water(containing 0.1% formic acid, A)-acetonitrile(B) with gradient elution. With electrospray ionization source, the data of 70% methanol extract from stem leaf, root and flower of I. sonchifolia were collected by high-resolution full-scan Fourier transform spectroscopy, data dependent acquisition, precursor ion scan, and selected ion monitoring in the negative and positive ion modes. The compounds were identified based on accurate molecular weight, retention time, fragment ions, comparison with reference standard, Clog P and references. A total of 131 compounds were identified from the 70% methanol extract of I. sonchifolia, including nucleosides, flavonoids, organic acids, terpenoids, and phenylpropanoids, and 119, 110, and 126 compounds were identified from the stem leaf, root and flower of I. sonchifolia, respectively. In addition, isorhamnetin, isorhamnetin-7-O-sambubioside and caffeylshikimic acid were discovered from I. sonchifolia for the first time. This study comprehensively analyzed and compared the chemical constituents in different parts of I. sonchifolia, which facilitated the discovery of effective substances and the development and application of medicinal material resources of I. sonchifolia.

Rapid Characterization of Chemical Constituents in Dayuanyin by UPLC-Q-Exactive Orbitrap MS / 中国实验方剂学杂志

ObjectiveTo characterize the chemical constituents of Dayuanyin based on ultra-performance liquid chromatography-quadrupole/electrostatic field orbitrap mass spectrometry（UPLC-Q-Exactive Orbitrap MS）. MethodThe detection was performed on a Thermo Acclaim™ RSLC 120 C18 column（2.1 mm×100 mm， 2.2 μm）， the mobile phase was acetonitrile（A）-0.1% formic acid aqueous solution（B） for gradient elution （0-7.5 min， 10%-19%A； 7.5-12 min， 19%-22.5%A； 12-23 min， 22.5%-27%A； 23-27 min， 27%-56%A； 27-35 min， 56%-84%A； 35-36 min， 84%-90%A）， the flow rate was 0.3 mL·min-1， and the column temperature was 30 ℃. The data were collected in the positive and negative ion modes by heated electrospray ionization（HESI）， and the detection range was m/z 80-1 200. Combining the retention time of the reference substance， fragment ions， databases such as PubChem and related literature， Xcalibur 3.0 was used to identify the chemical constituents of Dayuanyin. ResultA total of 161 compounds were identified， including 14 alkaloids， 60 flavonoids， 16 terpenoids， 26 saponins， 18 phenylpropanoids， 16 organic acids and 11 others. ConclusionThe established method can effectively and quickly identify the chemical components in Dayuanyin， and clarify its chemical composition， which can provide a basis for the development of compound preparations of this famous classical formula.

2,5-Diketopiperazines: A Review of Source, Synthesis, Bioactivity, Structure, and MS Fragmentation.

BACKGROUND: 2,5-Diketopiperazines (DKPs), also called cyclic dipeptides, are the simplest peptide derivatives in nature that are formed by the condensation of two amino acids. They are an important category of bioactive substances with various structures. OBJECTIVE: This review focuses on the natural sources, synthetic processes, biological properties and MS fragmentation regularity of simple DKPs, in order to provide a reference for exploring future scientific and therapeutic potentials of these compounds. METHODS: Pertinent information was collected and organized from several electronic scientific databases (e.g., Web of Science, China Knowledge Resource Integrated, ScienceDirect, PubMed, Wanfang Data and Google Scholar), PhD and MS dissertations. There are 107 articles published from the early 20th century to 2021 that were reviewed in this work. RESULTS: DKPs have been obtained from a broad range of natural resources, including fungi, bacteria, plants, and animals, and have been synthesized by chemical and biological methods. DKPs have various pharmacological activities, including anticancer, antibacterial, antithrombotic, neuron protective, analgesic, and other activities. Mass spectrometry is the most common method for the structural analysis of DKPs. DKPs can be quickly screened and identified by MS according to the mass spectrum fragmentation pattern. CONCLUSION: As a category of relatively unexplored compounds, DKPs have been demonstrated to have various bioactivities, especially with antitumor and antibacterial activities. However, the existing research on DKPs is still in the early stage, and their application in drug development needs to be further studied.

LC and LC-MS/MS studies for identification and characterization of degradation products of d-tubocurarine chloride.

Forced degradation studies of d-tubocurarine (DTC) was carried out in hydrolytic (acidic, alkaline and neutral), thermal, photolytic and oxidative degradation conditions as per International Conference on Harmonization (ICH) guideline Q1A (R2). The present study revealed that DTC is highly sensitive to oxidative degradation conditions even at room temperature whereas the drug was found to be stable in hydrolytic, photolytic and thermal stress conditions. Separation of DTC and its four degradation products (DPs) (DP-I to DP-IV) formed during stress degradation conditions were achieved on Waters Acquity CSH C18 (1.7 µm, 2.1 mm × 100 mm) column using gradient elution with a mobile phase consisting of Eluent-A: 0.1 % Formic acid Eluent-B: acetonitrile achieved successfully. The detection was carried out at 210 nm wavelength and the flow rate was kept at 0.3 mL/min with a 5 µL injection volume. Also, a highly sensitive and robust HRMS/MS/TOF method was established for the identification and characterization of four DPs formed during the stress study. ESI +ve mode was used throughout the study for ionization of all the DPs. The degradation pathway was also established in the study that is never reported earlier.

Comparative Analysis of Serum Pharmacochemistry of Alismatis Rhizoma Before and After Salt Processing Based on UPLC-Q-TOF-MS / 中国实验方剂学杂志

ObjectiveBased on serum pharmacochemistry and ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS） the transitional components in the serum of rats after intragastric administration of water extract of Alismatis Rhizoma（AR）and salt-processed Alismatis Rhizoma（SAR） were compared. MethodSD rats were randomly divided into blank group, AR group（10 g·kg-1） and SAR group（10 g·kg-1）, 3 rats in each group, the administration groups were given AR and SAR aqueous extracts by gavage, respectively, and the blank group was given an equal volume of drinking water by gavage once in the morning and once in the evening, for 3 consecutive days. Sixty minutes after the last administration, blood was collected from the eye orbits, and the serum samples were prepared. The serum samples were prepared on an ACQUITY UPLC BEH C18 column（2.1 mm×50 mm, 1.7 μm） with the mobile phase of acetonitrile（A）-0.1% formic acid aqueous solution（B） in a gradient elution（0-10 min, 10%-50% A; 10-27 min, 50%-95%A; 27-27.1 min, 95%-10% A; 27.1-30 min, 10%A）, the data were collected at a flow rate of 0.3 mL·min-1 in positive ion mode with a scanning range of m/z 100-1 200. Based on the self-constructed chemical composition library of AR, the total ion flow diagrams and secondary MS fragmentation information of the aqueous extracts of AR and SAR, as well as the administered serum and the blank serum, were compared with each other by UNIFI 1.9.2, so as to deduce the possible blood-migrating constituents and their cleavage patterns in the aqueous extracts, and the response intensity ratios of each chemical component were calculated before and after processing. ResultA total of 20 components, including 5 prototypical components and 15 metabolites, were analyzed and deduced from the serum of rats given aqueous extract of AR. And 14 components, including 5 prototypical components and 9 metabolites, were analyzed and deduced from the serum of rats given aqueous extract of SAR. Of these, 13 components were common to both of them, including 5 prototypical components and 8 metabolites. The 5 prototypical components were 16-oxoalisol A, alisol A 24-acetate, alisol A, alisol B and alisol C. The metabolites were mainly involved in phase Ⅰ metabolism（oxidation） and phase Ⅱ metabolism（glucuronidation）. There was a big change in the intensity of response of the common components before and after salt-processing, and the response intensities of the prototypical components, 16-oxoalisol A, alisol B and alisol C, were elevated, while the type and response intensity of metabolites were generally decreased, and it was hypothesized that the metabolic rate of terpenoids might be slowed down after salt-processing of AR, so that the blood-migrating constituents could participate in the metabolism of the body more in the form of prototypes. ConclusionSalt-processing of AR may promote the absorption of prototypical components into the blood by slowing down the metabolic rate of terpenoids, which can provide support for the research on material basis of AR and SAR.

Identification and characterization of forced degradation products of sertraline hydrochloride using UPLC, ultra-high-performance liquid Chromatography-Quadrupole-Time of flight mass spectrometry (UHPLC-Q-TOF/MS/MS) and NMR.

The present study focused on the forced degradation behavior of sertraline hydrochloride (SRT), selective serotonin reuptake inhibitor (SSRI). The drug was exposed to different stressed conditions (hydrolytic, oxidative, thermal and photolytic) according to ICH Q1A (R2) guidelines. The study revealed that SRT was stable in hydrolytic (acidic, basic and neutral) and thermal degradation conditions. In contrast, five degradation products (DPs) were formed under oxidative and photolytic degradation conditions. The chromatographic separation of drug substance and its DPs was achieved on an Acquity HSS T3 column (100 × 2.1 mm, 1.7 µ) using 0.1% formic acid and acetonitrile as the mobile phase in gradient mode using a UHPLC-DAD system. The DPs were identified and characterized by high-resolution LC/MS and LC/MS/MS in ESI positive mode. Two DPs (DP-I and DP-II) were formed when SRT was exposed to oxidative degradation conditions. Three DPs formed (DP III-V) when exposed to photolytic degradation conditions. All the five major DPs were isolated using Preparative HPLC. The structures of major DPs formed were further confirmed using NMR technique (1D and 2D). The proposed mechanism for the formation of the SRT DPs via the photolytic/oxidative stress degradation pathway are discussed and outlined.

Circulating cell free DNA and citrullinated histone H3 as useful biomarkers of NETosis in endometrial cancer.

BACKGROUND: Cancer mortality is mainly caused by organ failure and thrombotic events. It has been demonstrated that NETosis, a chromatin release mechanism implemented by neutrophils, may contribute to these lethal systemic effects. Our aim was to investigate NETosis biomarkers in endometrial cancer (EC). METHODS: The experiments were conducted on 21 healthy subjects (HS) with no gynecological conditions, and on 63 EC patients. To assess the presence of NETosis features, IHC and IF was performed using antibodies against citrullinated histone H3 (citH3), neutrophil elastase (NE) and histone 2B. Serum levels of cell free DNA (cfDNA), cell free mitochondrial DNA (cfmtDNA) and citH3 were measured by qPCR using one microliter of deactivated serum, and by ELISA assay respectively. Fragmentation pattern of serum cfDNA was analyzed using the Agilent 2100 Bioanalyzer and High Sensitivity DNA Chips. Receiver operating characteristic (ROC) analysis was used to identify a cut off for cfDNA and cfmtDNA values able to discriminate between ECs and HSs. Correlation analysis and multiple correspondence analysis (MCA) between cfDNA, mtcfDNA, citH3 and blood parameters were used to identify the potential association among serum parameters in EC grades. RESULTS: We demonstrated the presence of NETosis features in tissues from all EC grades. Serum cfDNA and cfmtDNA levels discriminate ECs from HSs and a direct correlation between citH3 and cfDNA content and an inverse correlation between cfmtDNA and citH3 in EC sera was observed, not detectable in HSs. MCA indicates cfDNA, cfmtDNA and citH3 as features associated to G1 and G2 grades. A correlation between increased levels of cfDNA, citH3 and inflammation features was found. Finally, serum nucleosomal cfDNA fragmentation pattern varies in EC sera and correlates with increased levels of cfDNA, citH3, lymphocytes and fibrinogen. CONCLUSION: Our data highlight the occurrence of NETosis in EC and indicate serum cfDNA and citH3 as noninvasive biomarkers of tumor-induced systemic effects in endometrial cancer.

Mass spectral analysis of secondary metabolites from Zingiber montanum rhizome extract using UHPLC-HR-ESI-QTOF-MS/MS.

INTRODUCTION: Zingiber montanum (J.Koenig) Link ex A.Dietr. is a popular medicinal plant in Thailand. Its rhizomes have been used as an ingredient in various Thai traditional medicine formulas. While many reports have focused on the chemical constituents and biological activities of this plant, a comprehensive study on secondary metabolite profiling using tandem mass spectrometry has, to this point, never been documented. OBJECTIVE: To analyze the chemical constituents in Z. montanum rhizomes using ultra-high performance liquid chromatography coupled with ultra-high-resolution electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-HR-ESI-QTOF-MS/MS) analyses and to utilize the characteristic fragmentation patterns of these compounds to facilitate their identification. METHODOLOGY: UHPLC-HR-ESI-QTOF-MS/MS in positive ion mode was used for chemical identification of secondary metabolites from the ethanolic extract of the plant material. MS/MS data of some known reference compounds, together with detailed fragmentation pattern information of several compounds obtained from the crude extract, were used to elucidate their chemical structures. RESULTS: In this work, one benzaldehyde, ten phenylbutenoid monomers, six curcuminoids, and nine phenylbutenoid dimers were assigned based on their characteristic fragment ions. Among these compounds, 2-(3,4-dimethoxystyryl)oxirane was tentatively suggested as a potential new compound. Several characteristic fragment ions from these compounds were assigned and the relative ion abundance of these was also used to differentiate the chemical structures of compounds having the same molecular mass. CONCLUSIONS: The results will benefit future high-throughput screening of bioactive compounds and method development for the quality control of raw materials and herbal drugs derived from Z. montanum rhizome extracts.

Identification of Antiprotozoal Compounds from Buxus sempervirens L. by PLS-Prediction.

Various nor-triterpene alkaloids of Buxus (B.) sempervirens L. have shown remarkable in vitro activity against the causative agents of tropical malaria and East African sleeping sickness. To identify further antiprotozoal compounds of this plant, 20 different fractions of B. sempervirens L., exhibiting a wide range of in vitro bioactivity, were analyzed by UHPLC/+ESI-QqTOF-MS/MS. The analytical profiles were investigated by partial least squares regression (PLS) for correlations between the intensity of LC/MS signals, bioactivity and cytotoxicity. The resulting models highlighted several compounds as mainly responsible for the antiprotozoal activity and thus, worthwhile for subsequent isolation. These compounds were dereplicated based on their mass spectra in comparison with isolated compounds recently reported by us and with literature data. Moreover, an estimation of the cytotoxicity of the highlighted compounds was derived from an additional PLS model in order to identify plant constituents with strong selectivity. In conclusion, high levels of antitrypanosomal and antiplasmodial activity were predicted for eight and four compounds, respectively. These include three hitherto unknown constituents of B. sempervirens L., presumably new natural products.

LC-MS/MS studies for identification and characterization of new forced degradation products of dabrafenib and establishment of their degradation pathway.

Dabrafenib (Tafinlar) is used for the treatment of patients with BRAF V600 mutation positive unresectable or metastatic melanoma. Forced degradation study of the drug product and drug substance is very much important in drug development and drug discovery to establish the intrinsic stability and understand its behaviors towards different stress conditions. In the current study, compressive stress testing of dabrafenib has been performed as per the recommendation of ICH guidelines to identify and characterize all major degradation products of dabrafenib (DPD) formed. Drug substances were exposed to different stressed conditions as per ICH recommendations. The present study observed that the dabrafenib drug substance is very much sensitive when exposed to oxidative degradation conditions at 80 °C temperature conditions and also sensitive to photolytic degradation conditions. Dabrafenib is stable when treated in acidic, alkaline, neutral and thermal degradation environments as there is no degradation observed in signification percentage under these stressed conditions. The best separation of eight degradation products and dabrafenib drug substance was obtained in Waters BEH (Ethylene Bridge Hybrid) C-18 column (1.7 µm, 100 mm × 2.1 mm) having mobile phase composed of Formic acid (0.1%) and methanol as Eluent A and Eluent B respectively using 225 nm wavelengths. The volume of injection (5 µL) and flow rate (0.3 mL/min) was set throughout the study. Dabrafenib is highly unstable to oxidative stressed conditions as five major degradation products (DPD-II, DPD-III, DPD-IV, DPD-V and DPD-VII) were obtained when exposed to hydrogen peroxide. When dabrafenib is treated under photolytic degradation conditions, three major DPs were formed (DPD-I, DPD-VI and DP-VIII). These DPs were further identified and characterized on sophisticated HRMS/MS/TOF technique for accurate mass measurement. Characterization of all the degradation products was carried out in the ESI positive mode of ionization. The establishment of the degradation pathway of drug substance and fragmentation pathway of DPs were explained in the present study which was never reported in any literature.

Two New Alkaloids from Fuzi and Their Metabolites Study.

Former study suggests alkaloids from herbs of Aconitum genus plants possess excellent bioactivities, which exert great value for related deeper chemical constituent investigation. Herein, chemical isolation was performed and four alkaloids were isolated from Fuzi, of which two were new ones, and the other two were reported NMR data for the first time. Their chemical structures were identified by NMR data, high resolution MS, UV and IR analysis. Additionally, the MS fragmentation patterns were explored, formerly, that of hetisane alkaloid was rarely reported, and fragmentation mechanism of the diagnostic ion was proposed. Based on these fragment pathway, metabolites and metabolic pathways of four compounds were investigated in rat liver microsomes using UPLC-Q/TOF-MS, and dehydrogenation product was firstly found from metabolites of hetisane alkaloid.

Mass Spectrometric Analysis of Cyclotides from Clitoria ternatea: Xxx-Pro Bond Fragmentation as Convenient Diagnostic of Pro Residue Positioning.

Cyclotides, a class of macrocyclic plant peptides, characterized by a cyclic backbone and three inter-locking disulfide bonds, may be divided into two major structural subfamilies, Möbius and Bracelet, based on the presence or absence of a specific proline residue. The present study describes the suite of cyclotides obtained from Clitoria ternatea, characterized by LC-MS and MS/MS techniques. Notable variations in product ion distributions were observed in cyclotides belonging to different structural subfamilies based on the number and positions of proline residues. For instance, Cter M which is an abundant Möbius cyclotide in this plant containing three proline residues, displayed distinct b- and y- ion characteristics in the MS/MS spectra compared to Cliotide T1, another commonly identified cyclotide but belonging to the Bracelet subfamily having two proline residues. The distinct fragmentation pattern of prototypical cyclotides of each structural subfamily, determined by Xxx-Pro bond fragmentation, was used to rapidly identify and sequence a novel cyclotide ctr pep 30 from this plant.

[Study on fragmentation patterns of coumarins in Notopterygium inchum with ultrahigh performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry].

To demonstrate the fragmentation patterns of simple coumarins furanocourmarin(C_7-C_8), furanocourmarin(C_6-C_7) and dihydrofuran coumarin by mass spectrometry, with fraxin, scopoletin, isopsoralen, pimpinellin, isoimperatorin, notopterol and noda-kenin as study subjects, so as to provide a basis for rapid identification of compounds in different subtypes of coumarins. Ultrahigh performance liquid chromatography combined with quardrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was implemented in both positive and negative ion modes. Masslynx software was employed to provide the elemental constituents of each detected ion based on its accurate molecular weight. Chemdraw 2014 was used to cultivate mass number of each inferred structure. The fragment pattern of each compound was determined based on the structures inferred from all the relevant ions. And the patterns were drawn by Chemdraw 2014. The deviation between the calculated molecular weight of the inferred structure and the detected value of the ions was used to assess the correctness of the inferred structures in the fragmentation patterns. The results showed that with UPLC-Q-TOF, neutral loss of CO_2 and CO was reflected in lactone and furan skeletons from the courmarin structure. An even mass was attributed to the loss of an odd number of methyl radicals from compounds with a methoxy substituent. Furanocourmarin(C_7-C_8) produced a protonated molecular ion([M+H]~+), while the other courmarin subtypes produced either a sodium adduct of the molecular ion([M+Na]~+) or a sodium adduct of the molecular ion([M+Na]~+) with a protonated molecular ion([M+H]~+). The m/z 203.03 was a diagnostic ion for furanocourmarin(C_6-C_7), and the m/z 147.04 was supplementary evidence for furanocourmarin(C_6-C_7) identification. The characteristic ion of furanocourmarin(C_7-C_8) was m/z 131.05, while m/z 187.04 was the characteristic ion of dihydrofuran coumarin. The m/z 203.03 ion for furanocourmarin(C_7-C_8) was pretty weak. In negative ion mode, furanocourmarin(C_7-C_8) did not have any signals that were different from the other subtypes of courmarins. The fragmentation patterns in negative ion mode for the other subtypes of courmarins were similar to those in positive ion mode. Four types of fragmentation patterns were identified as forcourmarins from Notopterygium inchum. This study provides the basis for the rapid identification of courmarin subtypes by mass spectrometry.

Differentiation of bisphenol F diglycidyl ether isomers and their derivatives by HPLC-MS and GC-MS-comment on the published data.

Positional isomers of bisphenol F diglycidyl ether (BFDGE) have been analyzed by high-pressure liquid chromatography-mass spectrometry and by gas chromatography-mass spectrometry (HPLC-MS, GC-MS). Positional isomers of BFDGE derivatives (BFDGEx2H2O, BFDGExH2OxHCl) have been analyzed by HPLC-MS. On the basis of the obtained fragmentation patterns, the elution order of the isomers has been unequivocally determined, in standard solutions and in the sample of liquid obtained after rinsing an empty mackerel fish can with acetonitrile. Under HPLC condition, para,para isomers are eluted first, then ortho,para isomers' elution follows, and ortho,ortho isomers are eluted last. Under GC condition, the reverse elution order has been obtained. For the first time, two ortho,para isomers of BFDGExH2OxHCl have been detected and their elution order has been determined. The obtained results are of key importance for determination of the isomer distribution of BFDGE and its derivatives in food samples.

Identification of Chemical Constituents in Chaishi Tuire Granules by UPLC-ESI-Q-TOF-MS/MS / 中国实验方剂学杂志

Objective:To rapidly identify the chemical constituents of Chaishi Tuire granules by ultra-performance liquid chromatography-electrospray/quadrupole time-of-flight tandem mass spectrometry （UPLC-ESI-Q-TOF-MS/MS）. Method:Chromatographic separation was conducted on a Phenomenex^® Luna omega C₁₈ column （2.1 mm×100 mm， 1.6 μm） with 0.1% formic acid aqueous solution （A）-acetonitrile （B） as the mobile phases for gradient elution （0-20 min， 5%-40%B； 20-40 min， 40%-95%B； 40-43 min， 95%B）， the flow rate was set at 0.3 mL·min^-1. MS data were collected in positive and negative ion modes， the scanning range was <italic>m</italic>/<italic>z</italic> 150-1 500 and electrospray ionization （ESI） was employed. The chemical constituents of Chaishi Tuire granules were identified by comparing with the retention time and the mass data of the reference substances， as well as the accurate mass， MS/MS fragment ions， mass spectrometry databases （PubChem， MassBank， ChemicalBook and others） and related literature. Result:A total of 85 chemical constituents were identified， including 28 flavonoids， 24 phenylpropanoids， 11 terpenoids， 10 alkaloids， 4 quinones， and 8 others. Among them， 19 constituents derived from Lonicerae Japonicae Flos， 14 constituents derived from Scutellariae Radix， 10 constituents derived from Isatidis Radix， 9 constituents derived from Taraxaci Herba， 9 constituents derived from Forsythiae Fructus， 4 constituents derived from Bupleuri Radix， 4 constituents derived from Anemarrhenae Rhizoma， and 4 constituents derived from Rhei Radix et Rhizoma. Conclusion:Chaishi Tuire granules is rich in phytochemicals， which are derived from many of traditional Chinese medicines. This study can lay a foundation for the quality control， material basis and <italic>in vivo</italic> metabolic analysis of this preparation.

Difference Analysis of Chemical Constituents in Different Varieties of Puerariae Flos by UPLC-Q-TOF-MS / 中国实验方剂学杂志

Objective:To compare the chemical constituents of Puerariae Flos from three different varieties of <italic>Pueraria montana</italic> var. <italic>lobata</italic>， <italic>P. montana</italic> var. <italic>thomsonii</italic> and <italic>P</italic>. <italic>montana</italic> var<italic>. montana</italic>. Method:Ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry （UPLC-Q-TOF-MS） was used with the mobile phase of 0.1% formic acid aqueous solution （A）-acetonitrile （B） for gradient elution （0-20 min， 10%-30%B； 20-30 min， 30%-55%B； 30-35 min， 55%-95%B； 35-37 min， 95%B； 37-40 min， 95%-10%B）， the flow rate was 0.25 mL·min^-1. Electrospray ionization （ESI） was used to scan and collect MS data in positive and negative ion modes with scanning range of <italic>m</italic>/<italic>z</italic> 50-1 500. The chemical components from different sources of Puerariae Flos were identified in combination with the chemical composition database and literature information. After the obtained data were normalized by MarkerView^TM 1.2.1， they were imported into SICMA-P 14.1 software for principal component analysis （PCA） and orthogonal partial least squares discriminant analysis （OPLS-DA） to select the main differentiated components among the three different varieties. Result:A total of 35 compounds were identified from three different varieties of Puerariae Flos， including 22 isoflavones， 6 flavonoids and 7 saponins. The flowers of <italic>P</italic>. <italic>lobata</italic>， <italic>P. montana</italic> var. <italic>thomsonii</italic> and <italic>P</italic>. <italic>montana</italic> var<italic>. montana</italic> contained 32， 35， 33 compounds， respectively. And 18 differential compounds were screened under the positive and negative ion modes， including kakkalide， tectoridin， 6″-<italic>O</italic>-xylosyl-tectoridin， 4'-methyltectorigenin-7-glucoside， glycitin， 6″-<italic>O</italic>-xylosyl-glycitin， irisolidone， kaikasaponin Ⅲ， 6″-<italic>O</italic>-malonylglycitin， kakkalidone， tectorigenin， rutin， soyasaponin BB， vitexin， biochanin A， genistin， kakkatin， azukisaponin Ⅱ. Conclusion:This research is the first to systematically study the chemical constituents of the flower of <italic>P</italic>. <italic>montana</italic> var<italic>. montana</italic>， although the flower of <italic>P</italic>. <italic>montana</italic> var<italic>. montana</italic> is used as adulterants， it has high contents of tectoridin and 6″-<italic>O</italic>-xylosyl-tectoridin， which has great potential for development. The efficacy components such as kakkalide and tectoridin in Puerariae Flos from the three sources of varieties are obviously different， and it is necessary to carefully consider the application of these three varieties as Puerariae Flos.

Analysis of Chemical Constituents in Qizhi Jiangtang Capsules Based on UPLC-QE-Orbitrap-MS / 中国实验方剂学杂志

Objective:To systematically analyze the chemical constituents of Qizhi Jiangtang capsules by ultra performance liquid chromatography-quadrupole-electrostatic field orbital trap high resolution mass spectrometry （UPLC-QE-Orbitrap-MS）. Method:Analysis was conducted on a ACQUITY UPLC HSS T3 column （2.1 mm×100 mm， 1.8 μm） with acetonitrile （A）-water （B） as the mobile phase for gradient elution （0-13 min， 1%-25%A； 13-21 min， 25%-35%A； 21-28 min， 35%-85%A； 28-30 min， 85%-100%A； 30-32 min， 100%-1%A）. The flow rate was 0.2 mL·min^-1， the column temperature was 30 ℃， and the volume of sample injection was 3 μL. Electrospray ionization （ESI） was used to collect data in the negative and positive ion modes with the scanning range of <italic>m</italic>/<italic>z</italic> 100-1 500. Meanwhile， a variety of MS analytic methods were used， including comparing with the information of control substances， self-built compounds database and literature references， diagnostic ion filtering， Compound Discoverer 3.0 software， for identification of the chemical components. Result:Based on the above strategy， a total of 52 compounds were identified in Qizhi Jiangtang capsules， and the sources of these compounds were identified. Amino acids were mainly derived from Hirudo， phenylpropanoids were derived from Astragali Radix and Rehmanniae Radix， iridoid glycosides were derived from Rehmanniae Radix， coumarins and triterpenes were derived from Astragali Radix， flavonoids were from Astragali Radix and Polygonati Rhizoma. Conclusion:The established UPLC-QE-Orbitrap-MS analytical method can comprehensively and rapidly analyze and identify of the chemical constituents in Qizhi Jiangtang capsules. Many of the ingredients have been proved by modern pharmacological studies to have the effect of improving related symptoms of diabetes and its complications， reflecting the characteristics of synergistic action of multiple components in Qizhi Jiangtang capsules. This study can provide reference for the further research on the pharmacodynamic material basis and the quality control of Qizhi Jiangtang capsules.