Effect of mobile phase additives on qualitative and quantitative analysis of ginsenosides by liquid chromatography hybrid quadrupole-time of flight mass spectrometry

Impact of four different extraction methods and three different reconstitution solvents on the untargeted metabolomics analysis of human and rat urine samples

Unsuitable sample preparation may result in loss of important analytes and consequently affect the outcome of untargeted metabolomics. Due to species differences, different sample preparations may be required within the same biological matrix. The study aimed to compare the in-house sample preparation method for urine with methods from literature and to investigate the transferability of sample preparation from human urine to rat urine. A total of 12 different conditions for protein precipitation were tested, combining four different extraction solvents and three different reconstitution solvents using an untargeted liquid-chromatography high resolution mass spectrometry (LC-HRMS) metabolomics analysis. Evaluation was done based on the impact on feature count, their detectability, as well as the reproducibility of selected compounds. Results showed that a combination of methanol as extraction and acetonitrile/water (75/25) as reconstitution solvent provided improved results at least regarding the total feature count. Additionally, it was found that a higher amount of methanol was most suitable for extraction of rat urine among the tested conditions. In comparison, human urine requires significantly less volume of extraction solvent. Overall, it is recommended to systematically optimize both, the extraction method, and the reconstitution solvent for the used biofluid and the individual analytical settings.

Targeted trace ingredients coupled with chemometric analysis for consistency evaluation of Panax notoginseng saponins injectable formulations

Evaluating the consistency of herb injectable formulations could improve their product quality and clinical safety, particularly concerning the composition and content levels of trace ingredients. Panax notoginseng Saponins Injection (PNSI), widely used in China for treating acute cardiovascular diseases, contains low-abundance (10%-25%) and trace saponins in addition to its five main constituents (notoginsenoside R1, ginsenoside Rg1, ginsenoside Re, ginsenoside Rb1, and ginsenoside Rd). This study aimed to establish a robust analytical method and assess the variability in trace saponin levels within PNSI from different vendors and formulation types. To achieve this, a liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) method employing multiple ions monitoring (MIM) was developed. A "post-column valve switching" strategy was implemented to eliminate highly abundant peaks (NR1, Rg1, and Re) at 26 min. A total of 51 saponins in PNSI were quantified or relatively quantified using 18 saponin standards, with digoxin as the internal standard. This study evaluated 119 batches of PNSI from seven vendors, revealing significant variability in trace saponin levels among different vendors and formulation types. These findings highlight the importance of consistent content in low-abundance and trace saponins to ensure product control and clinical safety. Standardization of these ingredients is crucial for maintaining the quality and effectiveness of PNSI in treating acute cardiovascular diseases.

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.

Integrated LC-MS and network pharmacology methods to screen quantitative indicators in the Hippocampus histrix Kaup and method transfer

Hippocampus histrix Kaup is a popular marine medicine with high medicinal and healthcare values. In this study, liquid chromatography-mass spectrometry (LC-MS) analysis combined with network pharmacological method was used to screen for suitable quantitative indicators for the quality control of H. histrix Kaup. Firstly, an LC-MS analytical method for the simultaneous determination of 12 nucleosides in extracts of H. histrix Kaup was established. And then, a network pharmacological method incorporated target prediction, protein-protein interaction network, components-targets network, and targets-pathways network was performed to screen for quantitative indicators. Finally, the developed LC-MS method was transferred to liquid chromatographs to improve the generalizability of the method. All 12 nucleotides were authenticated in extracts of H. histrix Kaup by comparing with the standards. The optimal chromatographic separation conditions are as follows: the chromatographic separation was achieved on an Acquire BEH-C18 column (2.1 mm * 100 mm, 1.7 µm) and gradient elution was performed using methanol solution and buffer (0.30% formic acid and 10 mmol/L ammonium acetate) as mobile phase at a flow rate of 0.15 mL/min and an acquisition wavelength of 260 nm. Network pharmacology results showed that adenosine, and uridine show excellent pharmacological activity. Integration the content, correlation, chromatographic separation, and pharmacological activity of each compound in H. histrix Kaup, uridine and adenosine were tentatively determined as quantitative indicators for quality control in H. histrix Kaup. The established LC-MS method was successfully transferred to liquid chromatographs, and the method is stable and reliable for the quality control of H. histrix Kaup. This developed integrated strategy was successfully used to screen quantitative indicators in the H. histrix Kaup.

Comparison of two methods for ginsenosides quantitation

The present study provides a comparison of two liquid chromatography-tandem mass spectrometry methods for ginsenosides analysis. The two methods have the same liquid chromatography separation procedure, and both use tandem mass spectrometry detection. However, one method uses multiple reaction monitoring transitions commonly recommended in the literature starting with [M + Na]⁺ as the molecular ions and with detection of specific fragment ions from the molecules M, while the other is an original method using [M + Cs]⁺ as molecular ions and Cs⁺ as fragment ion. The method using [M + Cs]⁺ as molecular ion has a very high sensitivity allowing the measurement of concentrations in the injecting solutions as low as 4 ng/ml with peaks at this concentration showing signal to noise ratio of 20 or higher. The procedures were utilized for the measurement of eight ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf (S), Rg1, and Rg2), although the method using [M + Cs]⁺ has the potential for measuring other ginsenosides. As an application, the ginsenosides were measured in several types of ginseng root, several dietary supplements containing ginseng extracts, four energy drinks, and a sample of ashwagandha.

Distribution visualization of the chlorinated disinfection byproduct of diazepam in zebrafish with desorption electrospray ionization mass spectrometry imaging

Diazepam (DZP) was routinely prescribed to a large population troubled with anxiety disorders. However, due to the overuse and misuse, DZP and its chlorination disinfection byproduct 2-methylamino-5-chlorobenzophenone (MACB) caused environmental pollution and can be detected ubiquitously in drinking water in Beijing, China. However, little information is known about the metabolic dynamics of MACB. Here, we established desorption electrospray ionization mass spectrometry (DESI-MS) imaging method to visually and quantitatively assess the distribution and metabolism of MACB in zebrafish. The results showed that MACB specifically accumulated in spinal cord particularly in female zebrafish. Meanwhile, the accumulation of MACB could pass through the blood-brain barrier (BBB) and induced microglial phagocytosis of neurons. Therefore, the intervention strategies should be explored to restrict the release of such substances, eliminating the potential risks for both human beings and the eco-environment.

Eco-Friendly, Simple, Fast, and Sensitive UPLC-MS/MS Method for Determination of Pexidartinib in Plasma and Its Application to Metabolic Stability

Pexidartinib is the first drug approved by the U.S. Food and Drug Administration specifically to treat the rare joint tumor tenosynovial giant cell tumor. In the current study, a validated, selective, and sensitive UPLC-MS/MS assay was developed for the quantitative determination of pexidartinib in plasma samples using gifitinib as an internal standard (IS). Pexidartinib and IS were extracted by liquid-liquid extraction using methyl tert-butyl ether and separated on an acquity BEH C18 column kept at 40 °C using a mobile phase of 0.1% formic acid in acetonitrile: 0.1% formic acid in de-ionized water (70:30). The flow rate was 0.25 mL/min. Multiple reaction monitoring (MRM) was operated in electrospray (ESI)-positive mode at the ion transition of 418.06 > 165.0 for the analyte and 447.09 > 128.0 for the IS. FDA guidance for bioanalytical method validation was followed in method validation. The linearity of the established UPLC-MS/MS assay ranged from 0.5 to 1000 ng/mL with r > 0.999 with a limit of quantitation of 0.5 ng/mL. Moreover, the metabolic stability of pexidartinib in liver microsomes was estimated.

Integrating multiple-chromatographic approaches to evaluate chemical consistency of Chang-Kang-Fang preparations from mixed-herb decoction and combined single-herb decoction

Chang-Kang-Fang formula (CKF), a multi-herbs traditional Chinese medicine (TCM) prescription for treating irritable bowel syndrome (IBS), has been clinically applied in the traditional form of mixed-herb decoction (MHD), or in the modern form of combined single-herb decoction (cSHD, so called dispensing granule decoction) in the near decades, but the chemical consistency between the MHD and cSHD is still unknown. Herein, a new strategy by integrating multiple-chromatographic approaches to characterize both polysaccharides and small molecules was developed to compare the chemical consistency between MHD and cSHD. Sixteen small molecules were simultaneously qualified and quantified by UPLC-QTOF-MS/MS, the molecular weight distribution of polysaccharides was characterized by HPGPC-ELSD, while the monosaccharide composition and total saccharides content were determined by HPLC-PDA and UV-VIS, respectively. It was found that the molecular weight range and monosaccharide composition of polysaccharides, as well as the composition of small molecules, were identical between MHD and cSHD. However, the contents of berberine, epiberberine, coptisine, palmatine, albiflorin and paeoniflorin in MHD were significantly lower than those in cSHD, whereas the content of polysaccharides in MHD was higher than that in cSHD, indicating that there is a significant difference in the quality between MHD and cSHD, in particular for the relative contents of major small molecules and polysaccharides. Whether or not these quality variations affect the efficacy and safety of CKF deserves further investigation.

Retention behavior of ginsenosides in a sulfo-based high performance liquid chromatography column

We herein report the use of a sulfo-based column and hydrophilic interaction chromatography (HILIC) to separate 14 ginsenosides, namely Rb1, Rb2, Rb3, Rc, Rd, Rf, Re, Rg1, Rg2, Rg3, Rh1, Rh2, F₂, and C-K. In addition to its rapid and efficient ability to separate these ginsenosides, the sulfo-based column exhibited a good relationship between the ginsenoside capacity factor (k') and molecular weight (M_w) and a strict elution order corresponding to the polarity (P) of the ginsenosides, as confirmed by thin layer chromatography.

Effects of chromatographic conditions and mass spectrometric parameters on the ionization and fragmentation of triterpene saponins of Ilex asprella in liquid chromatography-mass spectrometry analysis

High performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (HPLC-QTOF-MS) is widely used to qualitatively characterize the chemical profiles of herbal medicines, in which the generated adducts and fragments are crucial for confirming molecular ion (deprotonated/protonated ion) and deducing structure of detected components. However, how chromatographic and mass spectrometric (LC-MS) conditions/parameters affect the quantity and intensity of adducts and fragments of detected components is scarcely concerned. In present study, three types of triterpene saponins from the root of Ilex asprella (RIA) were selected as a case study to systematically investigate the effects of LC/MS conditions/parameters on their ionization and fragmentation, so as to obtain higher intensity (higher detection sensitivity) and quantity (rich information) of adducts and fragments for the characterization of components in RIA. It was found that for LC conditions, methanol as organic phase was more benefit for generating more adducts with higher intensity; formic acid as a modifier suppressed the formation of [M-2H]^2-, thus promoted the generation of other types of adducts at lower concentration but inhibited the generation when the concentration exceeded 0.1%. MS parameters affect scarcely the quantity but mainly intensity of adducts, cone voltage, source temperature and desolvation gas flow have relatively higher impacts when compared with other parameters. Collision energy affected both quantity and intensity of fragments. MS parameters at the medium value largely increased the quantity and intensity of adducts and fragments. Three-types of triterpene saponins presented structurally specific ionization and fragmentation due to their amounts of acidic substitutes. A total of 55 components were detected and definitely or tentatively identified in RIA under the optimized LC-MS conditions, among which 35 triterpene saponins were firstly discovered. This is the first report that proposes and validates a systematic approach for assessing the effects of LC/MS conditions/parameters on the ionization and fragmentation of analytes, which could be helpful for the optimization of LC-MS conditions for effective chemical profiling analysis of herbal medicines.

Development of an ammonium chloride-enhanced thermal-assisted-ESI LC-HRMS method for the characterization of chlorinated paraffins

Simultaneous quantification of short-, medium-, and long-chain chlorinated paraffins (CPs) in environmental matrices is challenging and has received much attention from environmental chemists. In this study, ammonium-chloride-enhanced liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) was developed for the first time to quantify CPs in sediments and aqueous samples. Three ionization sources, including atmospheric pressure chemical ionization (APCI), electrospray ionization (ESI), and thermal-assisted-ESI, were employed to examine the performance of ammonium chloride as the chloride ion supply reagent in comparison with traditional chloride ion supply reagent, dichloromethane. Ammonium chloride can be easily used with reversed-phase liquid chromatography (LC), whereas dichloromethane is not compatible with aqueous LC mobile phase. Furthermore, other anion-supply reagents, such as ammonium formate, ammonium acetate, and ammonium bromide, were also tested. It was concluded that the adducts of the CPs with the anions were reversible and could partially dissociate into deprotonated CP ions. The yield of deprotonated CP ions was associated with the gas-phase basicity of the deprotonated CP ions and the corresponding anions. Furthermore, collision-induced dissociation curves were drawn to quantify the stability of anionic CP adducts. The ammonium-chloride-enhanced LC-HRMS was further employed for identifying CPs in sediment samples and coupled with an online SPE method for detecting CPs in aqueous samples. This study may significantly contribute to the qualification and quantification of CPs in environmental matrices.

Advances in detection and quantification of methylcytosine and its derivatives

Methylation of the fifth carbon atom in cytosine is an epigenetic modification of deoxyribonucleic acid that plays important roles in numerous cellular processes and disease pathogenesis. Three additional states of cytosine, that is, 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine, have been identified and associated with the diagnosis and/or prognosis of diseases. However, accurate measurement of those intermediates is a challenge since their global levels are relatively low. A number of innovative methods have been developed to detect and quantify these compounds in biological samples, such as blood, tissue and urine, etc. This review focuses on recent advancement in detection and quantification of four cytosine modifications, based on which, the development, diagnosis, and prognosis of diseases could be monitored through non-invasive procedures.

UPLC-QTOF/MS-Based Nontargeted Metabolomic Analysis of Mountain- and Garden-Cultivated Ginseng of Different Ages in Northeast China

Aiming at further systematically comparing the similarities and differences of the chemical components in ginseng of different ages, especially comparing the younger or the older and mountain-cultivated ginseng (MCG), 4, 5, 6-year-old cultivated ginseng (CG) and 12, 20-year-old MCG were chosen as the analytical samples in the present study. The combination of UPLC-QTOF-MS^E, UNIFI platform and multivariate statistical analysis were developed to profile CGs and MCGs. By the screening analysis based on UNIFI, 126 chemical components with various structural types were characterized or tentatively identified from all the CG and MCG samples for the first time. The results showed that all the CG and MCG samples had the similar chemical composition, but there were significant differences in the contents of markers. By the metabolomic analysis based on multivariate statistical analysis, it was shown that CG_{4⁻6 years}, MCG_{12 years} and MCG_{20 years} samples were obviously divided into three different groups, and a total of 17 potential age-dependent markers enabling differentiation among the three groups of samples were discovered. For differentiation from other two kinds of samples, there were four robust makers such as α-linolenic acid, 9-octadecenoic acid, linoleic acid and panaxydol for CG_{4⁻6 years}, five robust makers including ginsenoside Re₁, -Re₂, -Rs₁, malonylginsenoside Rb₂ and isomer of malonylginsenoside Rb₁ for MCG_{20 years}, and two robust makers, 24-hydroxyoleanolic acid and palmitoleic acid, for MCG_{12 years} were discovered, respectively. The proposed approach could be applied to directly distinguish MCG root ages, which is an important criterion for evaluating the quality of MCG. The results will provide the data for the further study on the chemical constituents of MCG.

Plant Metabolomics: Maximizing Metabolome Coverage by Optimizing Mobile Phase Additives for Nontargeted Mass Spectrometry in Positive and Negative Electrospray Ionization Mode

Nontargeted screening methods with ultrahigh-performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight mass spectrometry have been extensively applied to plant metabolomics to very diverse scientific issues in plant metabolomics. In this study, different mobile phase additives were tested in order to improve the electrospray ionization process and to detect as many metabolites as possible with high peak intensities in positive and negative ionization mode. Influences of modifiers were examined for nonpolar and polar compounds, as optimal conditions are not always the same. By combining different additives, metabolite coverage could be significantly increased. The best results for polar metabolites in positive ionization mode were achieved by using 0.1% acetic acid and 0.1% formic acid in negative ionization mode. For measurements of nonpolar metabolites in positive ionization mode, the application of 10 mmol/L ammonium formate led to the best findings, while the use of 0.02% acetic acid was more appropriate in negative ionization mode.

Simultaneous assay of multiple antibiotics in human plasma by LC-MS/MS: importance of optimizing formic acid concentration

AIM

Optimal dosing of antibiotics in critically ill patients is complicated by the development of resistant organisms requiring treatment with multiple antibiotics and alterations in systemic exposure due to diseases and extracorporeal drug removal. Developing guidelines for optimal antibiotic dosing is an important therapeutic goal requiring robust analytical methods to simultaneously measure multiple antibiotics.

METHODS

An LC-MS/MS assay using protein precipitation for cleanup followed by a 6-min gradient separation was developed to simultaneously determine five antibiotics in human plasma.

RESULTS

The precision and accuracy were within the 15% acceptance range. The formic acid concentration was an important determinant of signal intensity, peak shape and matrix effects.

CONCLUSION

The method was designed to be simple and successfully applied to a clinical pharmacokinetic study.

Comprehensive Qualitative Ingredient Profiling of Chinese Herbal Formula Wu-Zhu-Yu Decoction via a Mass Defect and Fragment Filtering Approach Using High Resolution Mass Spectrometry

The Wu-Zhu-Yu decoction is a traditional Chinese medicine formula for the treatment of headache. To reveal its material basis, a rapid and reliable liquid chromatography-high resolution mass spectrometry method was established for comprehensive profiling of the chemical ingredients in the Wu-Zhu-Yu decoction. The method was used on a quadrupole time-of-flight mass spectrometer along with an advanced data processing procedure consisting of mass accuracy screening, mass defect filtering and fragment filtering. After eliminating interference with a filtering approach, the MS data profiling was made more distinct and accurate. With the optimized conditions of only 35 min LC separation and single sample injection of each positive or negative ion mode, a total of 168 compounds were characterized, including 23 evodiamine and its analogous alkaloids, 12 limonoids, 17 gingerols, 38 ginsenosides, 15 flavonoids, 16 organic acids, 14 alkaloids, 5 saponins, 3 2,2-dimethylchromenes and 25 other compounds. The fragmentation patterns of representative compounds were illustrated as well. Integrative qualitative analysis of the Wu-Zhu-Yu decoction by high resolution mass spectrometry was accomplished and reported for the first time. The study demonstrated that the established method was a powerful and reliable strategy for comprehensive detection and would be widely applicable for identification of complicated components from herbal prescriptions, and may provide a basis for chemical analysis of other complex mixtures.

Simultaneous Qualitative and Quantitative Analysis of Multiple Chemical Constituents in YiQiFuMai Injection by Ultra-Fast Liquid Chromatography Coupled with Ion Trap Time-of-Flight Mass Spectrometry

YiQiFuMai injection (YQFM) is a modern lyophilized powder preparation derived from the traditional Chinese medicine Sheng-mai san (SMS) used for treating cardiovascular diseases, such as chronic heart failure. However, its chemical composition has not been fully elucidated, particularly for the preparation derived from Ophiopogon japonicus. This study aimed to establish a systematic and reliable method to quickly and simultaneously analyze the chemical constituents in YQFM by ultra-fast liquid chromatography coupled with ion trap time-of-flight mass spectrometry (UFLC-IT-TOF/MS). Sixty-five compounds in YQFM were tentatively identified by comparison with reference substances or literature data. Furthermore, twenty-one compounds, including three ophiopogonins, fifteen ginsenosides and three lignans were quantified by UFLC-IT-TOF/MS. Notably, this is the first determination of steroidal saponins from O. japonicus in YQFM. The relative standard deviations (RSDs) of intra- and inter-day precision, reproducibility and stability were <4.9% and all analytes showed good linearity (R² ≥ 0.9952) and acceptable recovery of 91.8%–104.2% (RSD ≤ 5.4%), indicating that the methods were reliable. These methods were successfully applied to quantitative analysis of ten batches of YQFM. The developed approach can provide useful and comprehensive information for quality control, further mechanistic studies in vivo and clinical application of YQFM.

Appropriate choice of collision-induced dissociation energy for qualitative analysis of notoginsenosides based on liquid chromatography hybrid ion trap time-of-flight mass spectrometry

Liquid chromatography hybrid ion trap/time-of-flight mass spectrometry possessesd both the MS(n) ability of ion trap and the excellent resolution of a time-of-flight, and has been widely used to identify drug metabolites and determine trace multi-components for in natural products. Collision energy, one of the most important factors in acquiring MS(n) information, could be set freely in the range of 10%-400%. Herein, notoginsenosides were chosen as model compounds to build a novel methodology for the collision energy optimization. Firstly, the fragmental patterns of the representatives for the authentic standards of protopanaxadiol-type and protopanaxatriol-type notoginsenosides authentic standards were obtained based on accurate MS(2) and MS(3) measurements via liquid chromatography hybrid ion trap/time-of-flight mass spectrometry. Then the extracted ion chromatograms of characteristic product ions of notoginsenosides in Panax Notoginseng Extract, which were produced under a series of collision energies and, were compared to screen out the optimum collision energies values for MS(2) and MS(3). The results demonstrated that the qualitative capability of liquid chromatography hybrid ion trap/time-of-flight mass spectrometry was greatly influenced by collision energies, and 50% of MS(2) collision energy was found to produce the highest collision-induced dissociation efficiency for notoginsenosides. BesidesAddtionally, the highest collision-induced dissociation efficiency appeared when the collision energy was set at 75% in the MS(3) stage.

On-line stop-flow two-dimensional liquid chromatography-mass spectrometry method for the separation and identification of triterpenoid saponins from ginseng extract

A method based on stop-flow two-dimensional liquid chromatography coupled with electrospray ionization mass spectrometry (2D LC-ESI MS) was established and applied to analyze triterpenoid saponins from the main root of ginseng. Due to the special structure of triterpenoid saponins (they contain polar sugar side chains and nonpolar aglycones), hydrophilic interaction chromatography (HILIC) and reversed-phase liquid chromatography (RPLC) were used for the two dimensions, respectively. A trap column was used to connect the two dimensions. The dilution effect, which is one of the main shortcomings of traditional comprehensive 2D LC methods, was largely avoided. The peak capacity of this system was 747 and the orthogonality was 56.6 %. Compared with one-dimensional HILIC or RP LC MS analysis, 257 and 185 % more mass spectral peaks (ions with intensities that were higher than 1,000) were obtained from the ginseng main root extracts, and 94 triterpenoid saponins were identified based on MS(n) information and summarized aglycone structures. Given its good linearity and repeatability, the established method was successfully applied to classify ginsengs of different ages (i.e., years of growth), and 19 triterpenoid saponins were found through statistical analysis to vary in concentration depending on the age of the ginseng.

Quantitative Analysis of Panax ginseng by FT-NIR Spectroscopy

Near-infrared spectroscopy (NIRS), a rapid and efficient tool, was used to determine the total amount of nine ginsenosides in Panax ginseng. In the study, the regression models were established using multivariate regression methods with the results from conventional chemical analytical methods as reference values. The multivariate regression methods, partial least squares regression (PLSR) and principal component regression (PCR), were discussed and the PLSR was more suitable. Multiplicative scatter correction (MSC), second derivative, and Savitzky-Golay smoothing were utilized together for the spectral preprocessing. When evaluating the final model, factors such as correlation coefficient (R (2)) and the root mean square error of prediction (RMSEP) were considered. The final optimal results of PLSR model showed that root mean square error of prediction (RMSEP) and correlation coefficients (R (2)) in the calibration set were 0.159 and 0.963, respectively. The results demonstrated that the NIRS as a new method can be applied to the quality control of Ginseng Radix et Rhizoma.

Simultaneous determination of original, degraded ginsenosides and aglycones by ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry for quantitative evaluation of Du-Shen-Tang, the decoction of ginseng

In the present study, an ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) method for simultaneous determination of eleven original, fourteen degraded ginsenosides and five aglycones was developed and validated to quantitatively evaluate the transformation of ginsenosides during preparation of Du-Shen-Tang, the decoction of ginseng. Both positive and negative modes as well as the step wave ion transfer optics technology were used to increase the detection sensitivity of QTOF-MS. The extracting ion mode based on the quasi-molecular ions, molecular ions and fragment ions characteristic to each analyte was used to increase the selectivity for quantitative analysis. Under the optimized UHPLC and QTOF-MS conditions, the 30 analytes with different polarities were separated (except for Re and Rg1) within 26 min. The developed method was applied for the quantitative comparison of Du-Shen-Tang and its raw materials derived from Asian ginseng (ASG) and American ginseng (AMG), respectively. It was found that the contents of the original ginsenosides decreased from 26,053.09 to 19,393.29 μg/g or 45,027.72 to 41,865.39 μg/g, whereas the degraded ginsenosides and aglycones increased from 159.72 to 685.37 μg/g or 676.54 to 1,502.26 μg/g in Du-Shen-Tang samples of ASG or AMG when compared with their raw materials, indicating that decocting could dramatically increase the proportion of the less polar degraded ginsenosides in Du-Shen-Tang. Whether these changed proportions of different polar ginsenosides could affect the bioactivities of the decoctions and their raw materials derived from ASG and AMG deserves further investigation.