On-line coupling of macroporous resin column chromatography with direct analysis in real time mass spectrometry utilizing a surface flowing mode sample holder

Metabolite Fingerprinting for Identification of Panax ginseng Metabolites Using Internal Extractive Electrospray Ionization Mass Spectrometry

Ginseng, a kind of functional food and medicine with high nutritional value, contains various pharmacological metabolites that influence human metabolic functions. Therefore, it is very important to analyze the composition and metabolites of ginseng. However, the analysis of active metabolites in ginseng samples usually involves various experimental steps, such as extraction, chromatographic separation, and characterization, which may be time-consuming and laborious. In this study, an internal extractive electrospray ionization mass spectrometry (iEESI-MS) method was developed to analyze active metabolites in ginseng samples with sequential sampling and no pretreatment. A total of 44 metabolites, with 32 ginsenosides, 6 sugars, and 6 organic acids, were identified in the ginseng samples. The orthogonal partial least-squares discriminant analysis (OPLS-DA) score plot showed a clear separation of ginseng samples from different origins, indicating that metabolic changes occurred under different growing conditions. This study demonstrated that different cultivation conditions of ginseng can be successfully discriminated when using iEESI-MS-based metabolite fingerprints, which provide an alternative solution for the quality identification of plant drugs.

Phytochemical analysis of Panax species: a review

Panax species have gained numerous attentions because of their various biological effects on cardiovascular, kidney, reproductive diseases known for a long time. Recently, advanced analytical methods including thin layer chromatography, high-performance thin layer chromatography, gas chromatography, high-performance liquid chromatography, ultra-high performance liquid chromatography with tandem ultraviolet, diode array detector, evaporative light scattering detector, and mass detector, two-dimensional high-performance liquid chromatography, high speed counter-current chromatography, high speed centrifugal partition chromatography, micellar electrokinetic chromatography, high-performance anion-exchange chromatography, ambient ionization mass spectrometry, molecularly imprinted polymer, enzyme immunoassay, ¹H-NMR, and infrared spectroscopy have been used to identify and evaluate chemical constituents in Panax species. Moreover, Soxhlet extraction, heat reflux extraction, ultrasonic extraction, solid phase extraction, microwave-assisted extraction, pressurized liquid extraction, enzyme-assisted extraction, acceleration solvent extraction, matrix solid phase dispersion extraction, and pulsed electric field are discussed. In this review, a total of 219 articles published from 1980 to 2018 are investigated. Panax species including P. notoginseng, P. quinquefolius, sand P. ginseng in the raw and processed forms from different parts, geographical origins, and growing times are studied. Furthermore, the potential biomarkers are screened through the previous articles. It is expected that the review can provide a fundamental for further studies.

Fast quantitative analysis of ginsenosides in Asian ginseng (Panax ginseng C. A. Mayer) by using solid-phase methylation coupled to direct analysis in real time

RATIONAL

A fast quantitative method for ginsenosides is essential to minimize analysis time; direct analysis in real time mass spectrometry (DART-MS) has the potential to be used for this purpose.

METHODS

However, in order to produce ginsenosides, a derivatization such as methylation is required because the strong polarity of ginsenosides makes it difficult to desorp and ionize them in DART-MS. The main objectives of this study were to achieve fast detection and quantitative analysis of ginsenosides by using DART-MS; solid-phase methylation of ginsenosides has been accomplished in a reaction column; methylated products of ginsenosides Rb1, Rd, Re, Rf and Rg1 were analyzed by applying DART-MS where samples could be detected after methylation without the need for further purification. For quantitative analysis, deuterated methylated ginsenosides were prepared by using the solid-phase methylation method and used as internal standards to improve repeatability in DART-MS.

RESULTS

Methylated ginsenosides produced protonated molecules [M + H](+) and fragment ions in DART-MS. Two pairs of ginsenoside isomers, Rd/Re (C48 H82 O18 , MW 946) and Rf/Rg1(C42 H72 O14 , MW 800), could be discriminated based on their characteristic fragments in tandem mass spectrometry. By using deuterated methylated ginsenosides as internal standards, fast quantitative analysis of ginsenosides Rb1, Re and Rg1 in Asian ginseng was achieved by DART-MS.

CONCLUSIONS

DART-MS is a feasible technique for fast quantitative analysis of ginsenosides by assisted methylation and the deuterated internal standard technique. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of ion source operating parameters on direct analysis in real time of 18 active components from traditional Chinese medicine

Direct analysis in real time mass spectrometry (DART-MS) provides a new analytical method for traditional Chinese medicine (TCM). The present study investigated the effects of key ion source operating parameters on DART-MS analysis of various TCM active components. A total of 18 active components, including phenylpropanoids, alkaloids, saponins, flavones, volatile oils, and glycosides, were examined. For each substance, the peak area and signal-to-noise of its characteristic ions under different reagent gases and heater temperatures were compared. Based on the comparison, the relationships among chemical structures, ion source parameters and instrument responses were revealed. Finally, some suggestions about choosing reagent gas and heater temperature were proposed for types of TCM active substance, which offered a reference for the application of DART-MS on TCM analysis.

Recent progress on the traditional Chinese medicines that regulate the blood

In traditional Chinese medicine, the herbs that regulate blood play a vital role. Here, nine herbs including Typhae Pollen, Notoginseng Root, Common Bletilla Tuber, India Madder Root and Rhizome, Chinese Arborvitae Twig, Lignum Dalbergiae Oderiferae, Chuanxiong Rhizoma, Corydalis Tuber, and Motherwort Herb were selected and reviewed for their recent studies on anti-tumor, anti-inflammatory and cardiovascular effects. Besides, the analytical methods developed to qualify or quantify the active compounds of the herbs are also summarized.

Thermal-assisted gasification injector for analyzing high-salt solution samples: a novel device developed for online coupling of liquid chromatography with direct analysis in real time mass spectrometry

A thermal-assisted gasification injector was designed for online coupling of liquid-chromatography to direct-analysis-in-real-time mass-spectrometry. The method can be used in analysis with an inorganic salt matrix and weak polar solvent.