Rapid differentiation of Panax ginseng and Panax quinquefolius by matrix-assisted laser desorption/ionization mass spectrometry

Differential distribution of characteristic constituents in peel and pulp of Aurantii Fructus Immaturus (Citrus aurantium L.) using MALDI mass spectrometry imaging

Aurantii Fructus Immaturus (AFI) was structurally divided into two parts named "peel" and "pulp". The exocarp and mesocarp of materials named "peel". The endocarp separated into multiple compartments and the cystic hair attached to it named "pulp". In order to explore the distribution and content of constituents in AFI, an efficient method to explore the distribution of constituents was developed based on matrix assisted laser desorption/ionization fourier transform ion cyclotron resonance mass spectrometry imaging (MALDI-FTICR-MSI). After simple processing, thirty-two constituents with distinct localization in the mass range of 101-1200 Da were identified by MALDI-FTICR-MSI. In addition, the identified four flavnoids (poncirin, sinensetin, 3,5,6,7,8,3',4'-heptemthoxyflavone, and tangeritin) were analyzed for differences between using LC-MS. Quantitative analysis results supported the quantitative results from MALDI-FT-ICR-MSI. The results implied that different parts had different constituents in AFI, and demonstrated MALDI-MSI have high potential in the direct analysis of constituents.

Quantitative Analysis of Blended Oils Based on Intensity Ratios of Marker Ions in MALDI-MS Spectra

Determination of quantitative compositions of blended oils is an essential but challenging step for the quality control and safety assurance of blended oils. We herein report a method for the quantitative analysis of blended oils based on the intensity ratio of triacylglycerol marker ions, which could be obtained from the highly reproducible spectra acquired by using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to directly analyze blended oils in their oily states. We demonstrated that this method could provide good quantitative results to binary, ternary, and quaternary blended oils, with simultaneous quantitation of multiple compositions, and was applicable for quantitative analysis of commercial blended oil products. Moreover, the intensity ratio-based method could be used to rapidly measure the proportions of oil compositions in blended oils, only based on the spectra of the blended oils and related pure oils, making the method as a high-throughput approach to meet the sharply growing analytical demands of blended oils.

Advances in Fingerprint Analysis for Standardization and Quality Control of Herbal Medicines

Herbal drugs or herbal medicines (HMs) have a long-standing history as natural remedies for preventing and curing diseases. HMs have garnered greater interest during the past decades due to their broad, synergistic actions on the physiological systems and relatively lower incidence of adverse events, compared to synthetic drugs. However, assuring reproducible quality, efficacy, and safety from herbal drugs remains a challenging task. HMs typically consist of many constituents whose presence and quantity may vary among different sources of materials. Fingerprint analysis has emerged as a very useful technique to assess the quality of herbal drug materials and formulations for establishing standardized herbal products. Rather than using a single or two marker(s), fingerprinting techniques take great consideration of the complexity of herbal drugs by evaluating the whole chemical profile and extracting a common pattern to be set as a criterion for assessing the individual material or formulation. In this review, we described and assessed various fingerprinting techniques reported to date, which are applicable to the standardization and quality control of HMs. We also evaluated the application of multivariate data analysis or chemometrics in assisting the analysis of the complex datasets from the determination of HMs. To ensure that these methods yield reliable results, we reviewed the validation status of the methods and provided perspectives on those. Finally, we concluded by highlighting major accomplishments and presenting a gap analysis between the existing techniques and what is needed to continue moving forward.

Characterization of effective phytochemicals in traditional Chinese medicine by mass spectrometry

Traditional Chinese medicines (TCMs) have been widely used in clinical and healthcare applications around the world. The characterization of the phytochemical components in TCMs is very important for studying the therapeutic mechanism of TCMs. In the analysis process, sample preparation and instrument analysis are key steps to improve analysis performance and accuracy. In recent years, chromatography combined with mass spectrometry (MS) has been widely used for the separation and detection of trace components in complex TCM samples. This article reviews various sample preparation techniques and chromatography-MS techniques, including the application of gas chromatography-MS and liquid chromatography-MS and other MS techniques in the characterization of phytochemicals in TCM materials and Chinese medicine products. This article also describes a new ambient ionization MS method for rapid and high-throughput analysis of TCM components.

Visualizing the spatial distribution of endogenous molecules in wolfberry fruit at different development stages by matrix-assisted laser desorption/ionization mass spectrometry imaging

Wolfberry fruit has been attracting attention for centuries in Asian countries as a traditional herbal medicine and valuable nourishing tonic. Revealing the spatial distribution changes of important endogenous molecules during plant development is of great significance for investigating the physiological roles, nutritional and potential functional values of phytochemicals in wolfberry fruit. However, their spatial distribution information during fruit development has not been extensively explored due to the lack of efficient analytical techniques. In this work, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was performed to visualize the spatial distribution of the endogenous molecules during fruit development. From the mass spectrum imaging, the choline, betaine and citric acid were distributed evenly throughout the entire fruit at all development stages. The hexose was distributed in the endocarp and flesh tissue, while sucrose was located in the seeds. Additionally, several phenolic acids and flavonoids were accumulated in the exocarp during fruit development, which indicated that they seemingly played protective roles in wolfberry fruit growth progress against abiotic and biotic stress. From the collected data, we found that the signal intensities of citric acid were decreased, while choline, betaine, hexose and sucrose were increased with fruit development. These results indicate that MALDI-MSI may become a favorable tool for studying of the spatial distribution and effective use of endogenous molecules, which provide a simple and intuitive way for authenticity identification, classification of drug food homologous foods and further understanding the physiological roles of endogenous molecules.

Metabolomic approach for rapid differentiation of Fritillaria bulbs by matrix-assisted laser desorption/ionization mass spectrometry and multivariate statistical analysis

The bulbs of Fritillaria have been used for centuries as food and medicinal products in many Asian countries. Different Fritillaria species have distinct pharmacological effects despite of their similar appearances. Effective differentiation of Fritillaria species can avoid adulteration and is crucial to its clinical uses. In this paper, a hybrid method of matrix assisted laser desorption/ionization mass spectrometry and multivariate statistical analysis was developed for the rapid and reliable differentiation of Fritillaria species for the first time. Significantly different patterns for five Fritillaria species were obtained by MALDI-MS after instant sample extractions. Different groups of Fritillaria were confidently differentiated via an orthogonal partial least square model. In addition, a metabolomic taxonomy of five Fritillaria species was obtained based on MALDI-MS data.

Quality Analysis of American Ginseng Cultivated in Heilongjiang Using UPLC-ESI--MRM-MS with Chemometric Methods

American ginseng (Panax quinquefolium) has long been cultivated in China for the function food and medicine. Here, ultra-high performance liquid chromatography was coupled with electrospray ionization and triple quadrupole mass spectrometry (UPLC-ESI⁻-TQ-MS) for simultaneous detection of 22 ginsenosides in American ginseng cultivated in Mudanjiang district of Heilongjiang. The extraction conditions also were optimized by a Box Behnken design experiment. The optimized result was 31.8 mL/g as ratio of liquid to raw materials, 20.3 min of extraction time, and 235.0 W of extraction powers. The quantitative MS parameters for these 22 compounds were rapidly optimized by single factor experiments employing UPLC-ESI⁻-multiple reaction monitoring or multiple ion monitoring (MRM/MIM) scans. Furthermore, the established UPLC-ESI⁻-MRM-MS method showed good linear relationships (R² > 0.99), repeatability (RSD < 3.86%), precision (RSD < 2.74%), and recovery (94–104%). This method determined 22 bioactive ginsenosides in different parts of the plant (main roots, hairy roots, rhizomes, leaves, and stems) and growth years (one year to four years) of P. quinquefolium. The highest total content of the 22 analytes was in the hairy roots (1.3 × 10⁵ µg/g) followed by rhizomes (7.1 × 10⁴ µg/g), main roots (6.5 × 10⁴ µg/g), leaves (4.2 × 10⁴ µg/g), and stems (2.4 × 10⁴ µg/g). Finally, chemometric methods, hierarchical clustering analysis (HCA) and partial least squares discrimination analysis (PLS-DA), were successfully used to classify and differentiate American ginseng attributed to different growth years. The proposed UPLC-ESI⁻-MRM-MS coupled with HCA and PLS-DA methods was elucidated to be a simple and reliable method for quality evaluation of American ginseng.

UPLC Orbitrap HRMS Analysis of Panax quinquefolium L. for Authentication of Panax Genus with Chemometric Methods

Ginsenosides in Panax quinquefolium L. were determined using developed ultra-performance liquid chromatography coupled to high resolution mass spectrometry (UPLC-HRMS) method with electrospray ionization and orbitrap MS analyzer in negative ionization mode. Optimal UPLC separation was achieved using a mixture of acetonitrile and water with 0.1% formic acid as the mobile phase in linear gradient elution. The MS parameters were optimized for reliable detection with enhanced selectivity and sensitivity, and improved identification and quantification of ginsenosides. The applicability of this method was demonstrated on ginsenosides from Panax quinquefolium L. (American ginseng), Panax ginseng (Chinese ginseng) and Panax notoginseng (Sanchi) roots and products. The differences between Chinese and Northern American Panax quinquefolium L., main roots and hair roots, and products from different pharmacy were investigated. The results were also confirmed by principal component analysis and partial least squares discriminatory analysis. It indicated that the strategy can be extended to rapid and accurate authentication of Panax genus.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2011-2012

This review is the seventh update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2012. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, and fragmentation are covered in the first part of the review and applications to various structural types constitute the remainder. The main groups of compound are oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:255-422, 2017.

Identification and differentiation of Panax ginseng, Panax quinquefolium, and Panax notoginseng by monitoring multiple diagnostic chemical markers

To differentiate traditional Chinese medicines (TCM) derived from congeneric species in TCM compound preparations is usually challenging. The roots of Panax ginseng (PG), Panax quinquefolium (PQ) and Panax notoginseng (PN) are used as popular TCM. They contain similar triterpenoid saponins (ginsenosides) as the major bioactive constituents. Thus far, only a few chemical markers have been discovered to differentiate these three species. Herein we present a multiple marker detection approach to effectively differentiate the three Panax species, and to identify them in compound preparations. Firstly, 85 batches of crude drug samples (including 32 PG, 30 PQ, and 23 PN) were analyzed by monitoring 40 major ginsenosides in the extracted ion chromatograms (EICs) using a validated LC–MS fingerprinting method. Secondly, the samples were clustered into different groups by pattern recognition chemometric approaches using PLS-DA and OPLS-DA models, and 17 diagnostic chemical markers were discovered. Aside from the previously known Rf and p-F₁₁, ginsenoside Rs₁ could be a new marker to differentiate PG from PQ. Finally, the above multiple chemical markers were used to identify the Panax species in 60 batches of TCM compound preparations.

Localization of ginsenosides in Panax ginseng with different age by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry imaging

The root of Panax ginseng C.A. Mey. (P. ginseng) is one of the most popular traditional Chinese medicines, with ginsenosides as its main bioactive components. Because different ginsenosides have varied pharmacological effects, extraction and separation of ginsenosides are usually required for the investigation of pharmacological effects of different ginsenosides. However, the contents of ginsenosides vary with the ages and tissues of P. ginseng root. In this research, an efficient method to explore the distribution of ginsenosides and differentiate P. ginseng roots with different ages was developed based on matrix assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF-MSI). After a simple sample preparation, there were 18 peaks corresponding to 31 ginsenosides with distinct localization in the mass range of m/z 700-1400 identified by MALDI-TOF-MSI and MALDI-TOF-MS/MS. All the three types of ginsenosides were successfully detected and visualized in images, which could be correlated with anatomical features. The P. ginseng at the ages of 2, 4 and 6 could be differentiated finely through the principal component analysis of data collected from the cork based on the ion images but not data from the whole tissue. The experimental result implies that the established method for the direct analysis of metabolites in plant tissues has high potential for the rapid identification of metabolites and analysis of their localizations in medicinal herbs. Furthermore, this technique also provides valuable information for the component-specific extraction and pharmacological research of herbs.

Field-induced wooden-tip electrospray ionization mass spectrometry for high-throughput analysis of herbal medicines

This study demonstrates the first application of field-induced wooden-tip electrospray ionization (ESI) mass spectrometry (MS) for high-throughput analysis of herbal medicines. By application of an opposite and sample-contactless high voltage on the MS inlet rather than wooden tips, a high-throughput analysis device is easily set up, and a relatively fast analysis speed of 6 s per sample was successfully achieved. In addition, fast polarity switching between positive and negative ion detection mode is readily accomplished, which provides more complete chemical information for quality assessment and control of herbal medicines. By using the proposed method, various active ingredients present in different herbal medicines were rapidly detected, and the obtained mass spectra were served as the samples' fingerprints for tracing the origins, establishing the authenticity, and assessing the quality consistency and stability of herbal medicines. Our experimental results demonstrated that field-induced wooden-tip ESI-MS is a desirable method for high-throughput analysis of herbal medicines, with promising prospects for rapidly differentiating the origin, determining the authenticity, and assessing the overall quality of pharmaceuticals.

Metabolomic approach for discrimination of processed ginseng genus (Panax ginseng and Panax quinquefolius) using UPLC-QTOF MS

Discriminating between two herbal medicines (Panax ginseng and Panax quinquefolius), with similar chemical and physical properties but different therapeutic effects, is a very serious and difficult problem. Differentiation between two processed ginseng genera is even more difficult because the characteristics of their appearance are very similar. An ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF MS)-based metabolomic technique was applied for the metabolite profiling of 40 processed P. ginseng and processed P. quinquefolius. Currently known biomarkers such as ginsenoside Rf and F11 have been used for the analysis using the UPLC-photodiode array detector. However, this method was not able to fully discriminate between the two processed ginseng genera. Thus, an optimized UPLC-QTOF-based metabolic profiling method was adapted for the analysis and evaluation of two processed ginseng genera. As a result, all known biomarkers were identified by the proposed metabolomics, and additional potential biomarkers were extracted from the huge amounts of global analysis data. Therefore, it is expected that such metabolomics techniques would be widely applied to the ginseng research field.