Global Profiling and Novel Structure Discovery Using Multiple Neutral Loss/Precursor Ion Scanning Combined with Substructure Recognition and Statistical Analysis (MNPSS): Characterization of Terpene-Conjugated Curcuminoids in Curcuma longa as a Case Study

Comprehensive identification strategy for rapid profiling of chemical constituents using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry with Rhubarb as an example

In this study, the collision induced dissociation tandem mass spectrometry (CID-MS/MS) fragmentation pathway of chemical components in rhubarb was wholly explored using 34 standards by UHPLC-QTOF-MS/MS in negative ion mode. In consequently, the diagnostic product ions for speedy screening and categorization of chemical components in rhubarb were ascertained based on their MS/MS splitting decomposition patterns and intensity analysis. According to these findings, a fresh two-step data mining strategy had set up. The initial key step involves the use of characteristic product ions and neutral loss to screen for different types of substituents and basic skeletons of compounds. The subsequent key step is to screen and classify different types of compounds based on their characteristic product ions. This method can be utilized for rapid research, classification, and identification of compounds in rhubarb. A total of 356 compounds were rapidly identified or tentatively characterized in three rhubarb species extracts, including 150 acylglucoside, 125 anthraquinone, 65 flavanols and 15 other compounds. This study manifests that the analytical strategy is feasible for the analysis of complex natural products in rhubarb.

Precursor ions-guided comprehensive profiling of triterpenoid saponins from the Eleutherococcus senticosus stems and their neuroprotective effect evaluation

Triterpenoid saponins (TS) are the main constituents of Eleutherococcus senticosus, also termed as Siberian ginseng or Ciwujia, a widely used herb in China, Japan, Korea, and Russia for its beneficial effects on memory enhancement, tonifying, heart-nourishing, and tranquilizing. Although the stems, rhizomes, and roots are used identically, a preliminary experiment found TS were specifically distributed in stems rather than the underground parts. However, a comprehensive profiling of the TS compounds in E. senticosus stems (ESS) is still absent. In this study, an MS/MS molecular networking (MN)-based precursor ions (PIs) discovery strategy was applied to fast track the TS compounds from ESS extract. A total of 80 TS were tracked and characterized, among which 78 ones were reported for the first time in ESS. Furthermore, the TS-rich fraction (ESS-TS) was prepared by a series of chromatography separation, and was found with significant neuralprotective effects on attenuating Aβ25-35-induced neurite atrophy, and promoting the outgrowth of damaged neurite in the Aβ25-35-induced primary cortical neuronal damage model. In conclusion, this study highlighted the existence of TS compounds in ESS, a major medicinal parts nowadays adopted as Ciwujia by the Chinese Pharmacopiea and market. In addition, the TS was found with determined roles in the outgrowth of neuritis, and was proposed as crucial constituent when the E. senticosus was used as the therapeutic agents for neural diseases. These results supplies scientific data for the quality control of E. senticosus and the further development of ESS-TS as memory enhancement agents.

Systematical targeted multicomponent characterization and comparison of Arnebiae Radix and its three confusing species by offline two-dimensional liquid chromatography/LTQ-Orbitrap mass spectrometry

Arnebiae Radix, commonly known as "Zicao," can be easily confused with other compounding species, posing challenges for its clinical use. Here, we developed a comprehensive strategy to systematically characterize the diverse components across Arnebiae Radix and its three confusing species. First, an offline two-dimensional liquid chromatography (2D-LC) system integrating hydrophilic interaction chromatography (HILIC) and reverse phase (RP) separations was established, enabling effective separation and detection of more trace constituents. Second, a polygonal mass defect filtering (MDF) workflow was implemented to screen target ions and generate a precursor ion list (PIL) to guide multistage mass (MSn) data acquisition. Third, a three-step characterization strategy utilizing diagnostic ions and neutral losses was developed for rapid determination of molecular formulas, structure classes, and compound identification. This approach enabled systematic characterization of Arnebiae Radix and its three confusing species, with 437 components characterized including 112 shikonins, 22 shikonfurans, 144 phenolic acids, 131 glycosides, 18 flavonoids, and 10 other compounds. Additionally, 361, 230, 340, and 328 components were identified from RZC, YZC, DZC, and ZZC, respectively, with 142 common components and 30 characteristic components that may serve as potential markers for distinguishing the four species. In summary, this is the first comprehensive characterization and comparison of the phytochemical profiles of Arnebiae Radix and its three confusing species, advancing our understanding of this herbal medicine for quality control.

Shotgun-Based Mass Spectrometry Analysis of Phospholipid and Triacylglycerol Molecular Species and Eicosanoids in Salmon Muscle Tissue on Feeding Microbial Oil

The continuous growth of aquaculture places a growing demand on alternative sources of fish oil (FO). Certain microorganisms provide a sustainable replacement for FO due to their content of EPA and DHA, which are essential for fish health. Appreciable evidence shows that changes in feeding sources may alter the nutritional components of salmon; however, the influence of diets on lipid species remains unclear. In this study, the identification and semi-quantification of lipid molecular species in salmon muscle during feeding with a microbial oil (MO) were carried out by focusing on triacylglycerol (TAG) and diacyl-phospholipid using shotgun-based mass spectrometry analysis. DHA in the MO diet was efficiently incorporated into phospholipid structures on feeding, followed by accumulation in salmon muscle. The MO diet elevated the level of certain EPA-containing TAGs, such as TAG C52:5 (16:0_16:0_20:5) and TAG C54:6 (16:0_18:1_20:5), indicating that the MO diet may be an excellent source for enhancement of the abundance of ω3 lipids. Further, prostaglandins (PGs) PGE2 and PGF3α were identified and quantified for the first time in salmonid tissue.

Comprehensive analysis of different types of ginsenosides in the different parts of American ginseng by targeted and nontargeted MS/MS scanning

To comprehensively study the ginsenosides distribution in the various tissues of American ginseng, the qualitative and quantitative-targeted and nontargeted mass spectroscopic methods were established using the high-performance liquid chromatography coupled with Qtrap triple quadrupole mass spectrometry (HPLC-QtrapQQQ-MS). The total ginsenosides of the root, stem, and leaf of American ginseng were determined by a colorimetric method, and the contents showed the order from high to low root, stem, and leaf. Eighty-two kinds of ginsenosides were detected in the different parts of American ginseng by enhanced mass scan-information-dependent data acquisition (IDA)-enhanced product ion (EPI) scan mode, including 69 from the root, 62 from the stem, and 48 from the leaf. An HPLC-multiple reaction monitoring (MRM) method was established, and 28 representative ginsenosides were further quantified in the three parts. Nearly all ginsenosides had the highest contents in the root and the lowest content in the leaf. Three types of ginsenosides (protopanaxadiol [PPD]-, protopanaxatiol [PPT]-, and oleanolic acid [OA]-types) were analyzed by precursor ion-IDA-EPI and MRM-IDA-EPI scan modes. Root had the most abundant ginsenosides in PPD- and PPT-type ginsenosides. Meanwhile, the OA-type ginsenosides are significantly enriched in the stem and leaf of American ginseng. The results provided a supplement to the quality assessment of American ginseng. PRACTICAL APPLICATION: The distribution profile of ginsenosides in the parts of American ginseng is different. Except for the root, the stem, and leaf of American ginseng have the most abundant ginsenosides in oleanolic acid type. The results reported herein can help the manufacturers choose appropriate materials to extract the ginsenosides.

Targeted characterization and guided isolation of chemical components in Scrophulariae Radix based on LC-MS

How to achieve rapid characterization and efficient isolation of chemical components from traditional Chinese medicines (TCMs) is what the researchers have been exploring. Herein, a strategy integrated diagnostic ion filtering (DIF) and selected ion recording (SIR)-based screen was firstly proposed and successfully applied for targeted characterization and guided isolation of the chemical components from Scrophulariae Radix, one of TCMs. After acquiring the Q-TOF-MS/MS untargeted data, 128 compounds were characterized based on DIF, a self-built database and comparison of the related literatures, in which 38 compounds were reported for the first time. Subsequently, the SIR method of UPLC-QqQ-MS/MS was adopted to guide the isolation of potential new compounds. Finally, three new compounds together with one known compound with the same skeleton were isolated, and unambiguously elucidated by NMR and acid hydrolysis. These results indicated that this integrated analytical approach is effective and reliable in targeted characterizing chemical components and isolating new compounds from the extract of Scrophulariae Radix.

Qualitative and quantitative analysis of triterpenoids in different tissues of Pulsatilla chinensis

Pulsatilla chinensis (P.chinensis) is a traditional Chinese medicine used for the treatment of intestinal amebiasis diseases, vaginal trichomoniasis and bacterial infections. Tritepenoid saponins were important components of P.chinensis. Therefore, we asssessmented expression profiling of triterpenoids in different fresh tissues of P.chinensis by ultra high performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) and ultra high performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QQQ-MS). Firstly, we identified 132 triterpenoids, including 119 triterpenoid saponins, 13 triterpenoid acids and forty seven of them were first determined in Pulsatilla genus, including new aglycones and new ways of rhamnose linking to the aglycone. Secondly, we established the analytical method to analysis triterpenoids content of P.chinensis and comprehensively verified the analytical method by linearity, precision, repeatability, stability and recovery. At last, we quantified 119 triterpenoids simultaneously based on UHPLC-QQQ-MS. The results show that the types and contents of triterpenoids had obvious tissue distribution. New components like rhamnose directly linked to the aglycone mainely distributed in aboveground tissues. Additionally, We identified 15 chemical ingredients as differential components between the aboveground and underground tissues of P.chinensis. This study provides an efficient analysis strategy for the qualitative and quantitative analysis of triterpenoids in P.chinensis even in other traditional Chinese medicines. At the same time, it provides important informations to explain the biosynthetic pathway of triterpenoid saponins in P.chinensis.

Chemical profiling and quantitative analysis on the aqueous extract of Pimpinella anisum fruit by liquid chromatography-tandem mass spectrometry

Anise fruit (Aniseed) has been used for many years as a traditional medicine in various countries throughout the world; however, the chemical material basis of Aniseed water extract (AWE) has not been examined in detail, limiting our understanding of its pharmacological mechanism and methods for practical quality control. A high-efficiency and high-sensitivity LC-triple time-of-flight tandem mass spectrometry (MS/MS) analysis method using data processing method combined with product ion and neutral loss filtering for systematic screening and identification of the constituents of AWE was established. A quantitative method was established by using LC-MS/MS with multiple reaction monitoring for 10 min to determine the concentration of 17 representative constituents. A total of 89 compounds were discovered in AWE, of which 31 were confirmed by the reference standards, while 24 were found in Aniseed for the first time. The qualification analysis results showed that chlorogenic acids and luteolin derivatives were the major compounds. The linearity, sensitivity, precision, stability, repeatability, and accuracy of the method were verified, which demonstrated that the method could meet the requirements for quantification. This work contributes to a better understanding of the chemical material basis of Aniseed and assists in the development of effective analytical methods for natural medicines.

New Evidence for Artemisia absinthium as an Alternative to Classical Antibiotics: Chemical Analysis of Phenolic Compounds, Screening for Antimicrobial Activity

Artemisia absinthium, an important herb of the Artemisia genus, was evaluated in this study for its potential as an alternative to classical antibiotics. The antimicrobial activity of methanol extracts of A. absinthium (MEAA) was evaluated using the broth microdilution method, revealing that A. absinthium exhibited broad-spectrum antibacterial and antifungal activity. Ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS) was used to analyze the chemical profile of the MEAA, with a focus on flavonoids, quinic acids, and glucaric acids. A total of 90 compounds were identified, 69 of which were described for the first time in A. absinthium. Additionally, a new class of caffeoyl methyl glucaric acids was identified. The main active compounds were quantified and screened for antimicrobial activity. A. absinthium was found to be rich in quinic acids and flavonoids. The screening for antimicrobial activity also revealed that salicylic acid, caffeic acid, casticin, and 3,4-dicaffeoylquinic acid had varying degrees of antimicrobial activity. The acute toxicity of MEAA was examined following OECD guidelines. The administration of 5000 mg/kg bw of MEAA did not result in mortality in male and female mice. Furthermore, there were no observed effects on the visceral organs or general behavior of the mice, demonstrating the good safety of MEAA. This study provides new evidence for the use of A. absinthium as an alternative to classical antibiotics in addressing the problem of bacterial resistance.

Differentiating root and rhizome of panax notoginseng based on precursor ion scanning and multi heart-cutting two-dimensional liquid chromatography

Owing to increasing demand for Panax notoginseng-based medicines and health products, establishing a fast, simple, and reliable assay to analyze the chemical differences between its root and rhizome is important. Although previous studies showed that the chemical and biological differences between the root and rhizome of P. notoginseng seem to be small, efforts should be taken to investigate such differences to ensure the safety and efficacy of the products. This work describes a holistic approach that combines characteristic fingerprinting using ultra-high performance liquid chromatography-tandem mass spectrometry parent ion scanning with charged aerosol detection and targeted separation by online heart-cutting two-dimensional liquid chromatography, to identify and evaluate characteristic markers allowing differentiation of the root and rhizome. A total of five potential markers chikusetsusaponin L₅ , ginsenoside Rb₂ , stipuleanoside R_2, malonyl-ginsenoside Rb₁ , and malonyl-ginsenoside Rd, were identified and confirmed by comparing chromatographic retention time, the accurate mass of molecular weight, and the fragments of secondary MS with the available reference materials. The results showed that all five markers were 2.8-7 times higher in content in the rhizome than in the root.

Discovery of unreported ginkgolides of anti-PAF activity using characteristic ion and neutral loss recognition strategy in Ginkgo biloba L

Ginkgolides are the most important bioactive components of Ginkgo biloba L, of which ginkgolide B has been successfully developed and marketed as a drug. The reported ginkgolides are very rare and exhibit a complex matrix due to the chemodiversity of Ginkgo biloba L. Herein, the global profile of characteristic ion and neutral loss recognition strategy were used for to discover eight undescribed ginkgolides, very rare cyclohexane ginkgolides R-V, ginkgolides D-F, and eight known ginkgolides. These ginkgolides were target isolated and identified using high-resolution mass spectrometry, nuclear magnetic resonance spectroscopy, and X-ray crystallography. The undescribed and known ginkgolides exhibited antiplatelet aggregation activities. In particular, compounds U and D had IC₅₀ values of 2.20 ± 0.15 and 6.50 ± 0.87 μM, respectively. This study has enriched the known structural diversity of ginkgolides and extended the application of mass spectrometry to the global profiling of natural products present in Ginkgo biloba L. Moreover, it could help chemists rapidly discover unreported compounds from a complex matrix.

Characterization of prenylated phenolics in Glycyrrhiza uralensis by offline two-dimensional liquid chromatography/mass spectrometry coupled with mass defect filter

Prenylated phenolics are an important class of natural products. In this study, an efficient strategy was established to systematically characterize the prenylated phenolics in Glycyrrhiza uralensis, a popular herbal medicine. Firstly, offline two-dimensional liquid chromatography/mass spectrometry (2DLC/MS) coupled with mass defect filter (MDF) technology was used to preliminarily detect 1631 potential prenylated phenolics. Secondly, the tandem mass spectrometry fragmentation features of different types of prenylated phenolics were investigated using 29 reference standards. Diagnostic fragmentations included neutral loss (NL) of 42 Da for the annular type and NL of 56 Da for the catenulate type in the positive ion mode, and NL of 56 Da for A-ring prenyl groups and NL of 69 Da for B-ring prenyl groups in the negative ion mode. As a result, the prenylation types, substitution sites, and adjacent OH and OCH₃ substitutions of 320 prenylated phenolics in G. uralensis were rapidly characterized. Moreover, three prenylated dihydrostilbenes were purified from the aerial part of G. uralensis to verify the structural characterizations.

A novel hybrid scan approach enabling the ion-mobility separation and the alternate data-dependent and data-independent acquisitions (HDDIDDA): Its combination with off-line two-dimensional liquid chromatography for comprehensively characterizing the multicomponents from Compound Danshen Dripping Pill

Data-dependent acquisition (DDA) and data-independent acquisition (DIA)-based MSⁿ strategies are extensively applied in metabolites characterization. DDA gives accurate MSⁿ information, but receives low coverage, while DIA covers the entire mass range, but the precursor-product ions matching often yields false positives. Currently available MS scan approaches rarely integrate DIA and DDA within a duty circle. Utilizing a Vion™ IM-QTOF (ion mobility-quadrupole time-of-flight) mass spectrometer, we report a novel hybrid scan approach, namely HDDIDDA, which involves three scan events: 1) IM-enabled full scan (MS¹), 2) high-definition MS^E (HDMS^E) of all precursor ions (MS²); and 3) high-definition DDA (HDDDA) of top N precursors (MS²). As a proof-of-concept, the HDDIDDA approach combined with off-line two-dimensional liquid chromatography (2D-LC) was applied to characterize the multiple ingredients from a reputable Chinese patent medicine, Compound Danshen Dripping Pill (CDDP) used for treating the cardiovascular diseases. An off-line 2D-LC system by configuring an XBridge Amide column and an HSS T3 column showed a measurable orthogonality of 0.92 and enhanced the separation of co-eluting components. A fit-for-purpose HDDIDDA methodology was developed in the negative mode to characterize saponins and salvianolic acids, while tanshinones in the positive mode. Computational workflows to efficiently process the acquired HDMS^E and HDDDA data were established, and the searching of an in-house CDDP library (recording 712 compounds) eventually characterized 403 components from CDDP, indicating approximate 12-fold improvement compared with the previous report. The HDDIDDA approach can measure collision cross section of each component, and merges the merits of DIA and DDA in MS² data acquisition.

Applying Four-Step Characteristic Ion Filtering with HPLC-Q-Exactive MS/MS Spectrometer Approach for Rapid Compound Structures Characterization and Major Representative Components Quantification in Modified Tabusen-2 Decoction

Modified Tabusen-2 decoction (MTBD) is traditional Chinese Mongolia medicine, mainly used to treat osteoporosis. However, the precise material basis of this prescription is not yet fully elucidated. Herein, we establish an HPLC-Q-Exactive MS/MS spectrometer method with four-step characteristic ion filtering (FSCIF) strategy to quickly and effectively identify the structural features of MTBD and determine the representative compounds content. The FSCIF strategy included database establishment, characteristic ions summarization, neutral loss fragments screening, and secondary mass spectrum fragment matching four steps. By using this strategy, a total of 143 compounds were unambiguously or tentatively annotated, including 5 compounds which were first reported in MTBD. Nineteen representative components were simultaneously quantified with the HPLC-Q-Exactive MS/MS spectrometer, and it is suitable for eight batches of MTBD. Methodology analysis showed that the assay method had good repeatability, accuracy, and stability. The method established above was successfully applied to assess the quality of MTBD extracts. Collectively, our findings enhance our molecular understanding of the MTBD formulation and will allow us to control its quality in a better way. At the same time, this study can promote the development and utilization of ethnic medicine.

Full Collision Energy Ramp-MS2 Spectrum in Structural Analysis Relying on MS/MS

Albeit frequently being overlooked, MS² spectrum variation against collision energy (CE) implies auxiliary structural clues for m/z values. Online energy-resolved MS (ER-MS) provides the opportunity to acquire the trajectory of ion intensity against CE for any fragment ion of interest, thus exactly offering the desired momentum to empower the conventional MS² spectrum at a certain CE forward to a full-CE ramp MS² spectrum (FCER-MS²). Efforts were made here to construct an FCER-MS² spectrum and to evaluate its potential toward structural analysis. Flavonoids were employed as a proof of concept. MS² spectra of 76 compounds were recorded by LC-Q-Exactive-MS, and online ER-MS was subsequently programmed using LC-Qtrap-MS to build a breakdown graph for each obvious fragment ion. After defining the greatest value amongst all regressive apices as 100%, the normalized breakdown graphs comprised an FCER-MS² spectrum for each compound. The FCER-MS² spectrum contained the MS² spectrum at any CE as well as optimal CE (OCE) and maximal relative ion intensity (RII_max) of each fragment ion. Except the pronounced isomeric discrimination potential, either OCE or RII_max reflected certain structural properties, such as aglycone, glycosidic bond, and hydroxy, methoxy, and glycosyl substituents. These rules were subsequently applied for flavonoid-focused characterization of a famous herbal medicine, namely Scutellariae Radix, and high-level structural annotation was accomplished for 75 flavonoids. Above all, the FCER-MS² spectrum includes m/z, OCEs, and RII_max features, thus facilitating confidence-advanced structural analysis.

Turmeric and its bioactive constituents trigger cell signaling mechanisms that protect against diabetes and cardiovascular diseases

Turmeric, the rhizome of Curcuma longa plant belonging to the ginger family Zingiberaceae, has a history in Ayurvedic and traditional Chinese medicine for treatment of chronic diseases, including metabolic and cardiovascular diseases (CVD). This parallels a prevalence of age- and lifestyle-related diseases, especially CVD and type 2 diabetes (T2D), and associated mortality which has occurred in recent decades. While the chemical composition of turmeric is complex, curcuminoids and essential oils are known as two major groups that display bioactive properties. Curcumin, the most predominant curcuminoid, can modulate several cell signaling pathways involved in the etiology and pathogenesis of CVD, T2D, and related morbidities. Lesser bioactivities have been reported from other curcuminoids and essential oils. This review examines the chemical compositions of turmeric, and related bioactive constituents. A focus was placed on the cellular and molecular mechanisms that underlie the protective effects of turmeric and turmeric-derived compounds against diabetes and CVD, compiled from the findings obtained with cell-based and animal models. Evidence from clinical trials is also presented to identify potential preventative and therapeutic efficacies. Clinical studies with longer intervention durations and specific endpoints for assessing health outcomes are warranted in order to fully evaluate the long-term protective efficacy of turmeric.

Insight into chemical basis of traditional Chinese medicine based on the state-of-the-art techniques of liquid chromatography-mass spectrometry

Traditional Chinese medicine (TCM) has been an indispensable source of drugs for curing various human diseases. However, the inherent chemical diversity and complexity of TCM restricted the safety and efficacy of its usage. Over the past few decades, the combination of liquid chromatography with mass spectrometry has contributed greatly to the TCM qualitative analysis. And novel approaches have been continuously introduced to improve the analytical performance, including both the data acquisition methods to generate a large and informative dataset, and the data post-processing tools to extract the structure-related MS information. Furthermore, the fast-developing computer techniques and big data analytics have markedly enriched the data processing tools, bringing benefits of high efficiency and accuracy. To provide an up-to-date review of the latest techniques on the TCM qualitative analysis, multiple data-independent acquisition methods and data-dependent acquisition methods (precursor ion list, dynamic exclusion, mass tag, precursor ion scan, neutral loss scan, and multiple reaction monitoring) and post-processing techniques (mass defect filtering, diagnostic ion filtering, neutral loss filtering, mass spectral trees similarity filter, molecular networking, statistical analysis, database matching, etc.) were summarized and categorized. Applications of each technique and integrated analytical strategies were highlighted, discussion and future perspectives were proposed as well.

An integrated approach for structural characterization of Gui Ling Ji by traveling wave ion mobility mass spectrometry and molecular network

Gui Ling Ji (GLJ), an ancient reputable traditional Chinese medicine (TCM) formula prescription, has been applied for the treatment of oligospermia and asthenospermia in clinical practice. However, its inherent compounds have not yet been systematically elucidated, which hampers developing standards or guidelines for quality evaluation and even the understanding of pharmacological effects. In this study, an integrated approach has been established for comprehensive structural characterization of GLJ. Mass spectrometry datasets of GLJ and each of the single herb medicines in this prescription have been developed by dynamic exclusion fast data-dependent acquisition and high-definition data-independent acquisition modes on ultra-high-performance liquid chromatography coupled with travelling wave ion mobility quadrupole time-of-flight mass spectrometry (UPLC-TWIMS-QTOF-MS). A global natural product social molecular networking (GNPS) platform was then applied for the visualization of chemical space of GLJ and further for the high throughput identification of the targeted or untargeted compounds due to the support of data-transmitting from each single herbal medicine to the formula GLJ. Moreover, drift time, predicted CCS, and diagnostic fragment ions were induced for annotating isomer compounds. Consequently, based on molecular network and library hits, a total of 257 compounds from GLJ, which were classified into 4 structural types, were positively or tentatively characterized. Among them, 20 potential new compounds were detected and 30 pairs of isomers were comprehensively distinguished. The established strategy was effective for attribution, classification, recognition of various constituents, and also was valuable for integrating large amounts of disordered MS/MS data and mining trace compounds in other complex chemical or biochemical systems.

An integrated approach for structural characterization of Gui Ling Ji by traveling wave ion mobility mass spectrometry and molecular network.

An enhanced strategy integrating offline superimposed two-dimensional separation with mass defect filter and diagnostic ion filter: Comprehensive characterization of steroid alkaloids in Fritillariae Pallidiflorae Bulbus as a case study

The inherent complexity of traditional Chinese medicines necessitates the application of multi-dimensional information to accomplish comprehensive profiling and confirmative identification of their chemical components. In this study, we display an enhanced strategy by integrating offline superimposed two-dimensional separation (S-2D-LC) with mass defect filter and diagnostic ion filter to comprehensively characterize the alkaloid composition of Fritillariae Pallidiflorae Bulbus (FPB). The superimposed HILIC × RP and UPCC × RP offline two-dimensional liquid chromatography system was constructed with superior orthogonality (R²=0.004 and R²=0.001) for chromatographic separation. In total, 70 fractions were collected after the first-dimensional chromatographic separation (HILIC and UPCC) and then analyzed by the second-dimensional reversed phase (RP) liquid chromatography coupled with Q-TOF/MS/MS in FAST DDA acquisition mode. A four-step interpretation strategy combining mass defect filter with diagnostic ion filter was developed to rapidly characterize alkaloids in Fritillaria species. Ultimately, a sum of 529 Fritillaria alkaloids were characterized from two botanical origins of FPB. The integrated strategy is practical to efficiently expose and comprehensively characterize more trace and isomeric components in complex herbal medicines.

A global profiling strategy using comprehensive two-dimensional liquid chromatography coupled with dual-mass spectrometry platforms: Chemical analysis of a multi-herb Chinese medicine formula as a case study

Although ultraviolet detector or mass spectrometer could be coupled with two-dimensional liquid chromatography (2DLC) to analyze complex constituents, full detection and identification of the compounds are difficult. Suffering from biased UV detection and insufficient MS data interpretation, a number of minor compounds are neglected though they are separated. In this study, we report a global chemical profiling strategy using comprehensive 2DLC coupled with dual-MS platforms, including Orbitrap-MS and QqQ-MS. It was exemplified by an 11-herb Chinese medicine formula Xiaoer-Feire-Kechuan (XFK). Firstly, constituents in XFK were separated on a CSH C₁₈ × Phenyl-Hexyl 2DLC system with a practical peak capacity of 990.5 and an orthogonality of 90.3%. Secondly, untargeted mass spectral data was collected using dd-MS² scan on an Orbitrap-MS. In total 542 peaks were detected, which was 4 times of that detected by 2DLC/UV (131 peaks). A total of 108 compounds were tentatively identified. Thirdly, targeted mass spectral data was collected for 8 characteristic substructures using neutral loss and precursor ion (NL/PRE) scan on a QqQ-MS. Extracted ion chromatogram was used to recognize minor constituents. An additional of 151 compounds were detected. Our study indicated that comprehensive 2DLC coupled with dd-MS² and NL/PRE-MS is a powerful technique for the global profiling of multi-component systems.

An integrated strategy for comprehensive characterization of metabolites and metabolic profiles of bufadienolides from Venenum Bufonis in rats

Comprehensive characterization of metabolites and metabolic profiles in plasma has considerable significance in determining the efficacy and safety of traditional Chinese medicine (TCM) in vivo. However, this process is usually hindered by the insufficient characteristic fragments of metabolites, ubiquitous matrix interference, and complicated screening and identification procedures for metabolites. In this study, an effective strategy was established to systematically characterize the metabolites, deduce the metabolic pathways, and describe the metabolic profiles of bufadienolides isolated from Venenum Bufonis in vivo. The strategy was divided into five steps. First, the blank and test plasma samples were injected into an ultra-high performance liquid chromatography/linear trap quadrupole-orbitrap-mass spectrometry (MS) system in the full scan mode continuously five times to screen for valid matrix compounds and metabolites. Second, an extension-mass defect filter model was established to obtain the targeted precursor ions of the list of bufadienolide metabolites, which reduced approximately 39% of the interfering ions. Third, an acquisition model was developed and used to trigger more tandem MS (MS/MS) fragments of precursor ions based on the targeted ion list. The acquisition mode enhanced the acquisition capability by approximately four times than that of the regular data-dependent acquisition mode. Fourth, the acquired data were imported into Compound Discoverer software for identification of metabolites with metabolic network prediction. The main in vivo metabolic pathways of bufadienolides were elucidated. A total of 147 metabolites were characterized, and the main biotransformation reactions of bufadienolides were hydroxylation, dihydroxylation, and isomerization. Finally, the main prototype bufadienolides in plasma at different time points were determined using LC-MS/MS, and the metabolic profiles were clearly identified. This strategy could be widely used to elucidate the metabolic profiles of TCM preparations or Chinese patent medicines in vivo and provide critical data for rational drug use.

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Extension-mass defect filter model could reduce about 39% interfering ions.

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The optimized acquisition mode enhanced about 4 times acquisition capability than regular DDA mode.

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147 metabolites were characterized with metabolic network prediction, and the metabolic pathways were deduced in plasmas.

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The quantitative method of 14 prototypes was established by LC-MS/MS for metabolic profiles study.

Multi-marker scans coupled to high-resolution mass spectrometry strategy for global profiling combined with structure recognition of unknown trace chlorogenic acids in Lonicera Flos

Deep investigation, profiling of chemical diversity of constituent compounds and discovery of novel structures is a great challenge. A novel comprehensive and effective approach to mine trace unknown compounds combined with structure recognition in complex matrix is developed, in order to profiling potential Chlorogenic acids (CGAs) in Lonicera Flos (LFs): using multiple neutral loss/precursor ion (NL/PI) markers scans combined with high resolution mass spectrometry (HRMS). The workflow included (i) Fragmentation rules deduced by Q-orbitrap and selection of multiple NL/PI markers. (ii) Multiple NL/PI marker scans and grouping of peaks that had responses on two or more channels. (iii) Alignment of peaks in Full-MS scan and multiple NL/PI scans. (iv) The precursor ions list was introduced to mine novel CGAs according to simulated molecular formula. (v) Identification and structure recognition with the aid of HRMS. The procedure proved to be valid to screen and identify 51 CGAs from Lonicera Flos (LFs) with 16 categories, especially dihydroxyphenyl and glucoside for the first time. Its application could also be extended for global profiling of other complicated chemical systems, such as Chinese medicinal formulas.

Analytical Methods for Quantification and Identification of Intact Glucosinolates in Arabidopsis Roots Using LC-QqQ(LIT)-MS/MS

Glucosinolates are biologically active secondary metabolites in Brassicaceae plants that play a critical role in positive and negative interactions between plants and root-associated microbial communities. The aim of this study was to develop a reversed-phase liquid chromatography method to quantify and identify intact glucosinolates in the root of Arabidopsis thaliana (Arabidopsis) grown in non-sterile natural soil by using liquid chromatography-hybrid triple quadruple-linear ion trap (LC-QqQ(LIT)) mass spectrometry. The Synergi Fusion C18-based column was found to be effective for sufficient retention and separation of nine intact glucosinolates without the need for time-consuming desulfation or ion-pairing steps. Method validation results showed satisfactory inter-day and intra-day precision for all glucosinolates except for 4-hydroxyglucobrassicin. Good inter-day and intra-day accuracy and recovery results were observed for glucoiberin, gluconapin, glucobrassicin, 4-methoxyglucobrassicin and neoglucobrassicin. However, for 4-hydroxyglucobrassicin, glucoraphanin and glucoerucin corrections to quantification results might be necessary since the recovery and accuracy results were not optimal. Matrix effects were shown to have a negligible effect on the ionization of all target analytes. The established liquid chromatography–tandem mass spectrometry (LC-MS/MS) method was applied to quantify target intact glucosinolates in Arabidopsis root crude extract of four different wild-type accessions where differences in terms of concentration and composition of intact glucosinolates were observed. Employment of sensitive and selective precursor ion survey scan of m/z 97 in combination with the information-dependent acquisition (IDA) of the enhanced product ion (EPI) dependent scan (Prec97-IDA-EPI) using LC-QqQ(LIT) provided high confidence in structural characterization of diverse intact glucosinolate profiles in complex Arabidopsis root crude extract.

Offline two-dimensional liquid chromatography coupled with ion mobility-quadrupole time-of-flight mass spectrometry enabling four-dimensional separation and characterization of the multicomponents from white ginseng and red ginseng

Inherent complexity of plant metabolites necessitates the use of multi-dimensional information to accomplish comprehensive profiling and confirmative identification. A dimension-enhanced strategy, by offline two-dimensional liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (2D-LC/IM-QTOF-MS) enabling four-dimensional separations (2D-LC, IM, and MS), is proposed. In combination with in-house database-driven automated peak annotation, this strategy was utilized to characterize ginsenosides simultaneously from white ginseng (WG) and red ginseng (RG). An offline 2D-LC system configuring an Xbridge Amide column and an HSS T3 column showed orthogonality 0.76 in the resolution of ginsenosides. Ginsenoside analysis was performed by data-independent high-definition MSE (HDMSE) in the negative ESI mode on a Vion™ IMS-QTOF hybrid high-resolution mass spectrometer, which could better resolve ginsenosides than MSE and directly give the CCS information. An in-house ginsenoside database recording 504 known ginsenosides and 58 reference compounds, was established to assist the identification of ginsenosides. Streamlined workflows, by applying UNIFI™ to automatedly annotate the HDMSE data, were proposed. We could separate and characterize 323 ginsenosides (including 286 from WG and 306 from RG), and 125 thereof may have not been isolated from the Panax genus. The established 2D-LC/IM-QTOF-HDMSE approach could also act as a magnifier to probe differentiated components between WG and RG. Compared with conventional approaches, this dimension-enhanced strategy could better resolve coeluting herbal components and more efficiently, more reliably identify the multicomponents, which, we believe, offers more possibilities for the systematic exposure and confirmative identification of plant metabolites.

A holistic strategy for discovering structural analogues of drug residues in meat using characteristic structural fragments filtering by high-resolution Orbitrap mass spectrometry

A holistic strategy for discovering structural analogs was established using characteristic structural fragments filtering by high-resolution Orbitrap mass spectrometry and successfully employed for discovering potential hazards in meat. The mass spectrometry fragmentation mechanisms of 113 compounds (including sulphonamides, tetracyclines, benzimidazoles, steroid hormones, cephalosporins, β-blockers) were investigated and a new strategy for screening of characteristic fragment ions was proposed. To process the data acquired by two scan modes, firstly an integrated filtering strategy was conducted to facilitate the characterisation of multi-class drugs. The integrated filtering strategy was applied to reduce interference in the raw data, which could help extracting the MS1 characteristics of the homolog-type chemical substances and expand the screening of the compounds as effectively as possible. This strategy was based on a combination of nitrogen rule, neutral loss and multiple characteristic fragment ions filtering. The method was validated by rapid screening and identification of targeted compounds in spiked samples. Particularly, the successful detection of several new compounds indicated that this strategy had significant advantages over individual filtration methods and could be a promising method for screening and identifying newly homolog-type drug residues in complex samples.

Analysis of curcuminoids and volatile components in 160 batches of turmeric samples in China by high-performance liquid chromatography and gas chromatography mass spectrometry

Turmeric (Curcuma longa L.) is a popular herbal medicine worldwide. Curcuminoids and volatile constituents are its major bioactive components. To improve the quality control of turmeric, we determined the contents of three main curcuminoids in 160 batches of turmeric samples collected from five major production areas of China by HPLC, and analyzed the volatile components by GC/MS. The results indicated that samples with red cross sections (2.75 ± 0.82 mg/g) contained significantly higher amounts of curcuminoids than samples with yellow sections (1.23 ± 0.60 mg/g) (p < 0.001). This result was consistent with empirical standard of TCM pharmacists. The contents of curcuminoids in samples from Hainan (4.51±0.25%), Guizhou (3.17±0.41%), and Sichuan (2.25±0.54%) were relatively high and consistent. Moreover, the GC/MS profiles of turmeric may be affected by storage and processing. This study sets a good example for comprehensive quality control of herbal medicines.

Targeted characterization of acylated compounds from Scrophulariae Radix using liquid chromatography coupled with Orbitrap mass spectrometry and diagnostic product ion-based data analysis

Acylated compounds are often present in herbal medicines. In this study, a diagnostic product ion-based strategy was established to comprehensively characterize acylated compounds in Scrophulariae Radix. After untargeted data acquisition using ultra-high performance liquid chromatography coupled with Orbitrap mass spectrometry, the data were processed by three-stage diagnostic product ions. First, diagnostic product ions corresponding to the acyl groups (cinnamoyl, p-coumaroyl, feruloyl, and caffeoyl) were used to search 90 compounds. Second, these compounds were divided into three categories using diagnostic product ions for phenylethanoid glycosides, iridoid glycosides, and phenylpropanoids, respectively. Last, the linkage position of the acyl group to iridoid glycosides was discriminated via the third-stage diagnostic product ions. As a result, 90 acylated compounds were characterized, and 37 of them were reported from Scrophulariae Radix for the first time.

Center-of-Mass iso-Energetic Collision-Induced Decomposition in Tandem Triple Quadrupole Mass Spectrometry

Two scan modes of the triple quadrupole tandem mass spectrometer, namely Collision Induced Dissociation Precursor Ion scan and Neutral Loss scan, allow selectively pinpointing, in a complex mixture, compounds that feature specific chemical groups, which yield characteristic fragment ions or are lost as distinctive neutral fragments. This feature of the triple quadrupole tandem mass spectrometer allows the non-target screening of mixtures for classes of components. The effective (center-of-mass) energy to achieve specific fragmentation depends on the inter-quadrupole voltage (laboratory-frame collision energy) and on the masses of the precursor molecular ion and of the collision gas, through a non-linear relationship. Thus, in a class of homologous compounds, precursor ions activated at the same laboratory-frame collision energy face different center-of-mass collision energy, and therefore the same fragmentation channel operates with different degrees of efficiency. This article reports a linear equation to calculate the laboratory-frame collision energy necessary to operate Collision-Induced Dissociation at the same center-of-mass energy on closely related compounds with different molecular mass. A routine triple quadrupole tandem mass spectrometer can operate this novel feature (iso-energetic collision-induced dissociation scan; i-CID) to analyze mixtures of endogenous metabolites by Precursor Ion and Neutral Loss scans. The latter experiment also entails the hitherto unprecedented synchronized scanning of all three quadrupoles of the triple quadrupole tandem mass spectrometer. To exemplify the application of this technique, this article shows two proof-of-principle approaches to the determination of biological mixtures, one by Precursor Ion analysis on alpha amino acid derivatized with a popular chromophore, and the other on modified nucleosides with a Neutral Fragment Loss scan.

Real-time toxicity prediction of Aconitum stewing system using extractive electrospray ionization mass spectrometry

Due to numerous obstacles such as complex matrices, real-time monitoring of complex reaction systems (e.g., medicinal herb stewing system) has always been a challenge though great values for safe and rational use of drugs. Herein, facilitated by the potential ability on the tolerance of complex matrices of extractive electrospray ionization mass spectrometry, a device was established to realize continuous sampling and real-time quantitative analysis of herb stewing system for the first time. A complete analytical strategy, including data acquisition, data mining, and data evaluation was proposed and implemented with overcoming the usual difficulties in real-time mass spectrometry quantification. The complex Fuzi (the lateral root of Aconitum)–meat stewing systems were real-timely monitored in 150 min by qualitative and quantitative analysis of the nine key alkaloids accurately. The results showed that the strategy worked perfectly and the toxicity of the systems were evaluated and predicated accordingly. Stewing with trotters effectively accelerated the detoxification of Fuzi soup and reduced the overall toxicity to 68%, which was recommended to be used practically for treating rheumatic arthritis and enhancing immunity. The established strategy was versatile, simple, and accurate, which would have a wide application prospect in real-time analysis and evaluation of various complex reaction systems.

Characterization of Turmeric and Curry Samples by Liquid Chromatography with Spectroscopic Detection Based on Polyphenolic and Curcuminoid Contents

This paper deals with the characterization of turmeric and related products using the compositional fingerprints of curcuminoids (e.g., curcumin, demethoxycurcumin and bisdemethoxycurcumin) and other phenolic compounds (e.g., hydroxybenzoic and hydroxycinnamic acids and flavonoids) as the source of analytical information. Under this approach, the quantitative determination of analytes becomes unnecessary and even data from unknown components can be advantageously exploited for sample exploration and authentication. The methodology relied on sample extraction with hydro-organic solvents to recover the components of interest and further analysis of the corresponding extracts by liquid chromatography with diode array detection (HPLC-DAD). Extraction conditions were optimized focusing on the independent recovery of curcuminoids and polyphenols. Two different HPLC methods under reversed-phase mode were used to generate the chromatographic fingerprints at 420 and 280 nm for the specific monitoring of curcuminoids and polyphenols, respectively. Both extraction and separation steps were optimized under experimental design approaches to achieve the richest compositional fingerprints in terms of variety of components. The resulting data was subsequently treated chemometrically by principal component analysis (PCA) and related classification methods to achieve a better overall description of samples. Polyphenolic fingerprints were appropriate to discriminate among turmeric and mixed spices, while curcuminoid fingerprints could be useful to distinguish turmeric varieties.

Molecular species fingerprinting and quantitative analysis of saffron (Crocus sativus L.) for quality control by MALDI mass spectrometry

Herein we describe a rapid, simple, and reliable method for the quantitative analysis and molecular species fingerprinting of saffron (Crocus sativus L.) by direct MS and MS/MS analysis. Experimentally, powdered saffron was subjected to a brief treatment with a 0.3% TFA water/acetonitrile solution, and the resulting mixture was directly placed on the MALDI plate for analysis. This approach allowed the detection of the commonly observed crocins C-1-C-6 and flavonols, together with the identification of the unknown highly glycosylated crocins C-7, C-8 and C-9, and carotenoid-derived metabolites. The strategy endorsed the simultaneous detection and characterization of saffron and adulterant markers using crude extracts of the adulterant itself and synthetic sets of adulterated authentic saffron samples. The implementation of the strategy was to measure the amount of an unknown adulterant from the crude extract using curcumin as a non-isotopic isobaric internal standard. The relationship between the saffron and curcumin molar ratios were established with a correlation coefficient of 0.9942. The ANOVA regression model was significant, F(1, 72) = 13 595.82, p < 0.001, y = (0.0116 ± 0.0001)x + (-0.1214 ± 0.0086). No matrix effects were observed and good results were obtained with respect to instrumental repeatability (*RSD% < 2%) and LOD (1.1%). The analysis of commercial samples of saffron using the proposed approach showed the suitability of the method for routine analysis (minimal sample preparation and very short measuring time per sample).

An enhanced strategy integrating offline two-dimensional separation and step-wise precursor ion list-based raster-mass defect filter: Characterization of indole alkaloids in five botanical origins of Uncariae Ramulus Cum Unicis as an exemplary application

Comprehensive chemical profiling is of great significance for understanding the therapeutic material basis and quality control of herbal medicines, which is challenging due to its inherent chemical diversity and complexity, as well as wide concentration range. In this study, we introduced an enhanced strategy integrating offline two-dimensional (2D) separation and the step-wise precursor ion list-based raster-mass defect filter (step-wise PIL-based raster-MDF) scan by tandem LTQ-Orbitrap mass spectrometer. A comprehensive analysis of indole alkaloids in five botanical origins of Uncariae Ramulus Cum Unicis (Gou-Teng) was used as an exemplary application. A positively charged reversed phase (PR) × conventional RP LC system in different pH conditions was constructed with the orthogonality of 74%. A theoretical step-wise PIL among 310-950 Da with the step-size of 2 Da was developed to selectively trigger fragmentations and extend the coverage of potential indole alkaloids. Simultaneously, by defining parent mass width (PMW) of the step-wise PIL to ±55 mDa, a raster-MDF screening was achieved in the acquisition process. Additionally, subtype classification and structural elucidation were facilitated by a four-step interpretation strategy. As a result, a total of 1227 indole alkaloids were efficiently exposed and characterized from five botanical origins of Gou-Teng, which showed high chemical diversity. A systematic comparison among five species was first performed and only 66 indole alkaloids were common. For method validation, three new alkaloid N-oxides were isolated and unambiguously identified by NMR. The present study provides a novel data-dependent acquisition method with improved target coverage and high selectivity. The integrated strategy is practical to efficiently expose and comprehensively characterize complex components in herbal medicines.

Rapid profiling of polymeric phenolic acids in Salvia miltiorrhiza by hybrid data-dependent/targeted multistage mass spectrometry acquisition based on expected compounds prediction and fragment ion searching

Phenolic acids are the major water-soluble components in Salvia miltiorrhiza (>5%). According to previous studies, many of them contribute to the cardiovascular effects and antioxidant effects of S. miltiorrhiza. Polymeric phenolic acids can be considered as the tanshinol derived metabolites, e.g., dimmers, trimers, and tetramers. A strategy combined with tanshinol-based expected compounds prediction, total ion chromatogram filtering, fragment ion searching, and parent list-based multistage mass spectrometry acquisition by linear trap quadropole-orbitrap Velos mass spectrometry was proposed to rapid profile polymeric phenolic acids in S. miltiorrhiza. More than 480 potential polymeric phenolic acids could be screened out by this strategy. Based on the fragment information obtained by parent list-activated data dependent multistage mass spectrometry acquisition, 190 polymeric phenolic acids were characterized by comparing their mass information with literature data, and 18 of them were firstly detected from S. miltiorrhiza. Seven potential compounds were tentatively characterized as new polymeric phenolic acids from S. miltiorrhiza. This strategy facilitates identification of polymeric phenolic acids in complex matrix with both selectivity and sensitivity, which could be expanded for rapid discovery and identification of compounds from complex matrix.