Rapid isolation and identification of active antioxidant ingredients from Gongju using HPLC-DAD-ESI-MS(n) and postcolumn derivatization

Post-Chromatographic Derivatization Coupled with Mass Spectrometry as a Method of Profiling and Identification of Antioxidants; Ligustrum vulgare Phytocomplex as an Example

High-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) coupled with radical scavenging assays, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) can be both used for the detection of the antioxidants in plant extracts. In this study, the ethanolic (70% v/v) extracts from different morphological parts of Ligustrum vulgare collected at different stages of maturity were used as the source of antioxidants. The final identification of antioxidants was performed using high-resolution mass spectroscopy (HRMS). As a result, 19 compounds with antioxidant properties detected with HPLC-ABTS assay and 10 compounds detected with HPTLC-DPPH/ABTS assay were identified, mostly from the group of iridoids, phenylethanoids, and flavonoids. When comparing different L. vulgare samples, it was found that the extracts obtained from leaves contained the greatest number of antioxidants. The results of this study suggest that HPTLC-DPPH/ABTS as well as HPLC-ABTS derivatization coupled with the HRMS can be successfully used for profiling and identification of antioxidants from natural sources. Planar chromatography is more suitable for screening multiple samples because of its simplicity, whereas more challenging liquid chromatography provides more detailed information and is therefore better for a selected set of samples.

Integrated transcriptomics and lipidomics investigation of the mechanism underlying the gastrointestinal mucosa damage of Loropetalum chinense (R.Br.) and its representative component

BACKGROUND

Loropetalum chinensis (R.Br) Oliv (Bhjm), a Chinese folk herbal medicine, was traditionally used in the treatment of wound bleeding and skin ulcers. A new drug named JIMUSAN granules used for gastrosia was developed by our group, and clinical trials have been approved. However, as the principal herb, the material basis and underlying mechanisms of Bhjm in attenuating gastrointestinal mucosa damage (GMD) remain to be systemically illuminated.

PURPOSE

An integrated strategy was used to explore the therapeutic effects and mechanisms of Bhjm and ellagic acid (EA) on GMD zebrafish, using network pharmacology, transcriptomics, lipidomics, and real-time quantitative PCR (RT-qPCR) verification.

METHODS

First, network pharmacological analysis was used to infer the major effective constituents and targets of Bhjm. Ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UHPLC-LTQ-Orbitrap HRMS) and ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) were employed to identify the chemical constituents and quantify the different types of constituents. Second, zebrafish model of GMD was established by using 2,4,6-trinitrobenzenesulfonic acid (TNBS) to evaluate the efficacy of Bhjm and EA. The potential mechanism was examined by integrated transcriptomics and lipidomics analysis. Finally, validation tests were implemented using RT-qPCR.

RESULTS

In this study, targets indentified by network pharmacology were related to inflammation and mucosal damage. Ten representative components that interacted with these targets were simultaneously determined by UHPLC-MS/MS. Sixty four compounds were identified or tentatively characterized, most of which were flavonoids and polyphenols. Bhjm and EA alleviated mucosal damage and reduced inflammation in a TNBS-induced zebrafish GMD model, indicating that EA was the main active compounds. Eight common differentially expressed genes were downregulated by Bhjm and EA, as determined by transcriptomics analysis. Lipidomics analysis confirmed 12 differential lipids, including phosphatidylcholine (PC) and triglyceride (TG). Further network enrichment analysis demonstrated that differential lipid metabolism was regulated by klf4 and hist1h2ba, and were validated by RT-qPCR.

CONCLUSION

In our study, the chemical profile of Bhjm was clarified. Moreover, the GMD repair effect and the mechanism of Bhjm and EA was comprehensively analyzed for the first time, involving inflammation and lipid metabolism. Collectively, these findings will be significantly helpful for deeply exploring the clinical application value of Bhjm.

Study on the chemical profile of chrysanthemum and the evaluation of the similarities and differences between different cultivars

Chrysanthemum originates in China and has been cultivated for tea and food utilizations over 2 thousand years. According to differences in origin and processing methods, Chrysanthemum morifolium Ramat. can be categorized into many cultivars. This study aims to investigate the chemical components of chrysanthemum and clarify the similarities and differences between different chrysanthemum varieties. A total of 55 non-volatile components and 66 volatile components in chrysanthemum were identified by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and gas chromatography-mass spectrometry (GC-MS) methods, respectively. A rapid UPLC-MS/MS method was developed and validated for the simultaneous determination of 13 active components in 30 batches chrysanthemum samples of ten different cultivars. Multivariate statistical techniques were applied to analyze the samples. The result indicated that Boju, Huaiju and Chuju were more similar in terms of the ingredient content and Qiju, Jinsihuangju, Huangju, Hangju, Gongju, Fubaiju, Baiju have a high degree of similarity. Furthermore, isochlorogenic acid C, luteolin, apigenin-7-glucoside, chlorogenic acid, apigenin and cryptochlorogenic acid plays an important role in distinguishing different varieties of chrysanthemum. The established strategy explains the similarities and differences between different varieties of chrysanthemums to some extent, and provides certain reference value for the choice of chrysanthemums for eating or medicinal purposes in daily life.

Discovery of Quality Markers of Nucleobases, Nucleosides, Nucleotides and Amino Acids for Chrysanthemi Flos From Different Geographical Origins Using UPLC-MS/MS Combined With Multivariate Statistical Analysis

Nucleobases, nucleosides, nucleotides and amino acids, as crucial nutrient compositions, play essential roles in determining the flavor, function and quality of Chrysanthemi Flos. The quality of Chrysanthemi Flos from different geographical origins is uneven, but there have been no reports about the screening of their quality markers based on nutritional ingredients. Here, we developed a comprehensive strategy integrating ultra performance liquid chromatography coupled with triple-quadrupole linear ion-trap tandem mass spectrometry (UPLC-MS/MS) and multivariate statistical analysis to explore quality markers of Chrysanthemi Flos from different geographical origins and conduct quality evaluation and discrimination of them. Firstly, a fast, sensitive, and reliable UPLC-MS/MS method was established for simultaneous quantification 28 nucleobases, nucleosides, nucleotides and amino acids of Chrysanthemi Flos from nine different regions in China. The results demonstrated that Chrysanthemi Flos from nine different cultivation regions were rich in the above 28 nutritional contents and their contents were obvious different; however, correlation analysis showed that altitude was not the main factor for these differences, which required further investigation. Subsequently, eight crucial quality markers for nine different geographical origins of Chrysanthemi Flos, namely, 2'-deoxyadenosine, guanosine, adenosine 3',5'-cyclic phosphate (cAMP), guanosine 3',5'-cyclic monophosphate (cGMP), arginine, proline, glutamate and tryptophan, were screened for the first time using partial least squares discriminant analysis (PLS-DA) and the plot of variable importance for projection (VIP). Moreover, a hierarchical clustering analysis heat map was employed to intuitively clarify the distribution of eight quality markers in the nine different regions of Chrysanthemi Flos. Finally, based on the contents of selected eight quality markers, support vector machines (SVM) model was established to predict the geographical origins of Chrysanthemi Flos, which yielded excellent prediction performance with an average prediction accuracy of 100%. Taken together, the proposed strategy was suitable to discover the quality markers of Chrysanthemi Flos and could be used to discriminate its geographical origin.

An Effective Workflow for Differentiating the Same Genus Herbs of Chrysanthemum morifolium Flower and Chrysanthemum Indicum Flower

C. morifolium flower and C. indicum flower are two closely related herbal species with similar morphological and microscopic characteristics but are discriminated in edible and medicinal purpose. However, there is no effective approach to distinguish the two herbs. A novel workflow for quickly differentiating C. morifolium flower and C. indicum flower was developed. Firstly, the difference in anti-inflammatory effects for C. morifolium flower and C. indicum flower was characterized using lipopolysaccharide-treated rats. Then HPLC fingerprint analysis for 53 batches of C. morifolium flowers and 33 batches of C. indicum flower was carried out to deep profile the chemical components. The preliminary markers were screened out by OPLS-DA, identified by HPLC-ESI-QTOF-MS, and quantified by the improved SSDMC (single reference standard to determine multiple compounds) approach. Finally, multiple statistical data mining was performed to confirm the markers and a binary logistic regression equation was built to differentiate C. morifolium flower and C. indicum flower successfully. In general, the established workflow was rapid, effective and highly feasible, which would provide a powerful tool for herb identification.

Solvent effect on phenolics and antioxidant activity of Huangshan Gongju (Dendranthema morifolium (Ramat) Tzvel. cv. Gongju) extract

Huangshan Gongju was extracted with organic solvents (ethanol, methanol and acetone) of different concentrations (0-90%), and the extracts' phenolic content and antioxidant activity, as well as the correlations between them were examined. With the increasing concentration of organic solvent, the total phenolic compound (TPC) increased continuously and met its maximum at 70% acetone, whereas the total flavonoid compound (TFC) and most individual phenolics met their maximums at 70% ethanol. Similar changes occurred to the antioxidant activity, including DPPH and ABTS scavenging activities, and their maximums were respectively found at 50% acetone and 70% ethanol. The antioxidant activity correlated strongly with TPC/TFC (r > 0.954, p < 0.01) and individual phenolics (r > 0.886, p < 0.05), and the strongest correlations between them were mainly given by luteolin-7-O-glucoside (r > 0.975, p < 0.001). These results suggested that high content organic solvent (50-70%) was beneficial to obtain Huangshan Gongju extracts of higher phenolic content and antioxidant activity, and 70% ethanol may be the promising solvent. Besides, phenolics were found to be the main antioxidants of Huangshan Gongju extracts, and flavonoids especially luteolin-7-O-glucoside may play more important roles in the antioxidant activity.

An integration of UPLC-DAD/ESI-Q-TOF MS, GC-MS, and PCA analysis for quality evaluation and identification of cultivars of Chrysanthemi Flos (Juhua)

BACKGROUND

Chrysanthemi Flos (CF), as a popular traditional Chinese medicine (TCM), has five main cultivars in China, namely "Chuju", "Boju", "Gongju", "Huaiju" and "Hangju". Due to their habitats and processing methods, great quality variations occur yet no systematical study has ever been carried out to evaluate such variations.

PURPOSE

In this study, we aim to establish a new approach that can serve both as a quality control method and as an identification method for cultivars of CF.

METHOD

The components in CF samples were identified by a combination of UPLC-ESI-Q-TOF/MS and GC/MS. Furthermore, a multimodal quantitative method was established by UPLC-UV coupled with principal component analysis (PCA) and the similarity evaluation system (SES), which was used to control and identify four cultivars of CF.

RESULTS

18 compounds of flavonoids and caffeoylquinic acids were identified and ten of them were quantified using UPLC-ESI-Q-TOF/MS. Different cultivars of CF could be clearly distinguished with the fingerprints evaluation and principal component analysis (PCA). A total of 74 volatile compounds were detected by GC/MS. The distinctness of volatile components was observed. By the combination of UPLC-ESI-Q-TOF/MS and GC/MS, an identification and quality control method for CF was successfully established.

CONCLUSION

The combination of UPLC-ESI-Q-TOF/MS and GC/MS could act as a comprehensive multimodal method for both identification and quality control of herbal medicines. This study provided new insights into the overall evaluation method for herbal medicines possessing different cultivars.

Characterization of tyrosinase inhibitory constituents from the aerial parts of Humulus japonicus using LC-MS/MS coupled online assay

In the screening of natural products for the development as cosmetic ingredients, the EtOAc-soluble fraction of Humulus japonicus showed tyrosinase inhibitory activity. HPLC-MS/MS coupled online tyrosinase assay of EtOAc-soluble fraction of H. japonicus characterized the twenty-eight constituents including two unknown ones and their tyrosinase inhibitory activity. Fractionation of H. japonicus using various chromatographic techniques yielded thirty-eight compounds. The chemical structures of isolated compounds were identified by spectroscopic analysis. As characterized by HPLC-MS/MS analysis, we isolated twenty-four predicted compounds and further identified two unknown ones, named humulusides A (1) and B (2). Additional ten compounds were also identified by purification. Tyrosinase inhibitory activity of isolated compounds were evaluated, which was closely correlated with the results from HPLC-MS/MS coupled online tyrosinase assay. Consistent with predicted data, two major compounds, trans-N-coumaroyltyramine (14) and cis-N-coumaroyltyramine (15) showed tyrosinase inhibition with IC₅₀ values of 40.6 and 36.4 μM. Taken together, H. japonicus is suggested as whitening ingredient in cosmetic products. In addition, HPLC-MS/MS coupled tyrosinase assay is powerful tool for predicting active compounds with short time and limited amounts, although identification of new compounds and verification of predicted data are also needs to be demonstrated by further experiment.

Plant Phenolics Extraction from Flos Chrysanthemi: Response Surface Methodology Based Optimization and the Correlation Between Extracts and Free Radical Scavenging Activity

Huaiju is one of the most famous and widely used Flos Chrysanthemi (FC) for medicinal purposes in China. Although various investigations aimed at phenolics extraction from other FC have been reported, a thorough optimization of the phenolics extraction conditions from Huaiju has not been achieved. This work applied the widely used response surface methodology (RSM) to investigate the effects of 3 independent variables including ethanol concentration (%), extraction time (min), and solvent-to-material ratio (mL/g) on the ultrasound-assisted extraction (UAE) of phenolics from FC. The data suggested the optimal UAE condition was an ethanol concentration of 75.3% and extraction time of 43.5 min, whereas the ratio of solvent to material has no significant effect. When the free radical scavenging ability was used as an indicator for a successful extraction, a similar optimal extraction was achieved with an ethanol concentration of 72.8%, extraction time of 44.3 min, and the ratio of solvent to material was 29.5 mL/g. Furthermore, a moderate correlation between the antioxidant activity of TP extract and the content of extracted phenolic compounds was observed. Moreover, a well consistent of the experimental values under optimal conditions with those predicted values suggests RSM successfully optimized the UAE conditions for phenolics extraction from FC.

PRACTICAL APPLICATION

The work of the research investigated the plant phenolics in Flos Chrysanthemi and antioxidant capacities. These results of this study can support the development of antioxidant additive and relative food.

UPLC-PDA quantification of chemical constituents of two different varieties (golden and royal) of apple leaves and their antioxidant activity

BACKGROUND

Malus domestica is the most widely cultivated fruit tree and is well known for its therapeutic value. Apple leaves are known to contain phenolic compounds but the nature of these has not been explored to the same extent as in apple fruit. A simple, rapid and sensitive ultra-performance liquid chromatography-diode array detection (UPLC-DAD) quantification method has been developed. Total polyphenol and flavonoid contents, as well as the antioxidant activity of golden and royal apple leaves were evaluated.

RESULTS

Four compounds, namely rutin, 3-hydroxyphloridzin, phloridzin and quercetin-3-O-arabinoside were identified by UPLC. The separation was achieved in less than 7 min. Total polyphenol and flavonoid contents were found to be slightly higher in apple golden variety than royal variety. The IC50 values determined by the DPPH assay were 49.94 µg mL(-1) for golden apple leaves and 43.89 µg mL(-1) for royal apple leaves. IC50 values determined by the ABTS assay were 47.10 and 66.53 µg mL(-1) for golden and royal apple leaves, respectively. Antioxidant activity was determined as 24.45 and 21.15 mg ascorbic acid g(-1) for golden and royal apple leaves, respectively, by using the FRAP assay.

CONCLUSION

This study showed that apple leaves (both varieties) contain considerable amounts of polyphenols and flavonoids and are also a promising source of phloridzin.

Identification, synthesis, and safety assessment of forchlorfenuron (1-(2-chloro-4-pyridyl)-3-phenylurea) and its metabolites in kiwifruits

Identification and evaluation of safety of forchlorfenuron ((1-(2-chloro-4-pyridyl)-3-phenylurea)), 1, metabolites after biotransformation in kiwifruit is the objective of this study. To elucidate properties of these metabolites, liquid chromatography hybrid ion trap time-of-flight mass spectrometry (LC-IT-TOF-MS) was applied, with MetID Solution and Formula Predictor Software in positive mode. Cytotoxicity of forchlorfenuron and its metabolites were tested through sulforhodamine B assays against normal Chinese hamster ovary cells (CHO). As deduced from characteristic fragment ions of forchlorfenuron, then confirmed by comparison with synthetic standards, as well as characterized by NMR and mass spectrometry techniques, results indicate the presence of 4-hydroxyphenyl-forchlorfenuron, 2, 3-hydroxyphenyl-forchlorfenuron, 3, and forchlorfenuron-4-O-β-D-glucoside, 5. Forchlorfenuron (IC50 = 12.12 ± 2.14 μM) and 4-hydroxyphenyl-forchlorfenuron (IC50 = 36.15 ± 1.59 μM), exhibits significant cytotoxicity against CHO, while 3-hydroxyphenyl-forchlorfenuron and forchlorfenuron-4-O-β-D-glucoside show no cytotoxicity.