Separation and characterization of chemical constituents in Ginkgo biloba extract by off-line hydrophilic interaction × reversed-phase two-dimensional liquid chromatography coupled with quadrupole-time of flight mass spectrometry

Identification and quantification of the antioxidants in Ginkgo biloba leaf

The antioxidant activity of Ginkgo biloba leaf (GBL) extract is closely related to its efficacy against various diseases; however, the antioxidant activities of the specific constituents of GBL remain unclear. In this study, 194 GBL constituents were identified using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry, including 97 flavonoids, 37 terpenoids, 29 lignans, 19 carboxylic acids, 5 alkylphenolic acids, 5 alkylphenols, and 2 other compounds. The cleavage rules of the main constituents of GBL were dissected in detail. The 36 GBL constituents with high antioxidant activity were subsequently discovered using the oxygen radical absorbance capacity assay, including 30 flavonoids and six carboxylic acids. Finally, an HPLC analysis method was established to determine the content of the nine major antioxidants in the three batches of GBL. Among them, kaempferol 3-O-β-D-(6″-p-coumaroyl) glucopyranosyl-(1-2)-α-L-rhamnopyranoside, kaempferol-3-O-rutinoside, and rutin exhibited high antioxidant activity and were found in significant amounts in GBL, with concentrations greater than 0.7 mg/g. These results provide an important reference for the development of pharmaceuticals and health products containing GBL.

Onion (Allium cepa L.) Flavonoid Extract Ameliorates Osteoporosis in Rats Facilitating Osteoblast Proliferation and Differentiation in MG-63 Cells and Inhibiting RANKL-Induced Osteoclastogenesis in RAW 264.7 Cells

Osteoporosis, a prevalent chronic health issue among the elderly, is a global bone metabolic disease. Flavonoids, natural active compounds widely present in vegetables, fruits, beans, and cereals, have been reported for their anti-osteoporotic properties. Onion is a commonly consumed vegetable rich in flavonoids with diverse pharmacological activities. In this study, the trabecular structure was enhanced and bone mineral density (BMD) exhibited a twofold increase following oral administration of onion flavonoid extract (OFE). The levels of estradiol (E2), calcium (Ca), and phosphorus (P) in serum were significantly increased in ovariectomized (OVX) rats, with effects equal to alendronate sodium (ALN). Alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) levels in rat serum were reduced by 35.7% and 36.9%, respectively, compared to the OVX group. In addition, the effects of OFE on bone health were assessed using human osteoblast-like cells MG-63 and osteoclast precursor RAW 264.7 cells in vitro as well. Proliferation and mineralization of MG-63 cells were promoted by OFE treatment, along with increased ALP activity and mRNA expression of osteoprotegerin (OPG)/receptor activator of nuclear factor-kappaB ligand (RANKL). Additionally, RANKL-induced osteoclastogenesis and osteoclast activity were inhibited by OFE treatment through decreased TRAP activity and down-regulation of mRNA expression-related enzymes in RAW 264.7 cells. Overall findings suggest that OFE holds promise as a natural functional component for alleviating osteoporosis.

Screening and characterization of potential anti-gout components from Polygonum cuspidatum by integration off-line two-dimensional liquid chromatography-mass spectrometry with affinity ultrafiltration and on-line HPLC-ABTS

Polygonum cuspidatum (P. cuspidatum) is a traditional herbal medicine with a long history and proven efficacy in treating gout. However, due to the complexity of composition and extensive content distribution, the substance basis of its anti-gout effectiveness is still unclear. A strategy was proposed via integrating off-line two-dimensional liquid chromatography (2D-LC) and targeted rapid screening technology based on ultrafiltration-liquid chromatography-mass spectrometry (UF-LC/MS) and on-line high-performance liquid chromatography-2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (HPLC-ABTS) to accomplish high coverage and high throughput screening of anti-gout components from P. cuspidatum. As a result, twenty components were screened from P. cuspidatum extract with both xanthine oxidase (XOD) inhibitory activity and free radical scavenging activity, then were preliminarily identified by high-resolution electrospray ionization-quadrupole-time-of-flight mass spectrometer (ESI-Q-TOF/MS). The screened results were verified by the in vitro assays. Meanwhile, molecular docking further elucidated that the screened bioactive ingredients had favourable binding capabilities with XOD. The performance of this study can achieve high efficiency and high coverage screening of the anti-gout components from P. cuspidatum, which provides methodology and strategy support for the rapid screening of bioactive ingredients from complex medicinal plants.

Separation, identification, and fingerprinting of antioxidant components in persimmon (Diospyros kaki) leaves by offline two-dimensional liquid chromatography with electrochemical detection and tandem mass spectrometry

In this work, the antioxidant components in persimmon (Diospyros kaki) leaves were separated by offline two-dimensional liquid chromatography-electrochemical detection (LC×LC-ECD) and identified by LC-tandem mass spectrometry (LC-MS/MS). A total of 33 antioxidants, mainly proanthocyanidins, and glycosides of kaempferol and quercetin, were identified. The antioxidant assays demonstrated that the fractions collected from the first-dimension LC (1D-LC) possessed considerable radical scavenging capabilities, with correlation coefficients of peak area versus radical scavenging capability of 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) being 0.9335 and 0.9116, respectively. The fingerprinting showed that 37 peaks were present in all samples. The major antioxidant components of persimmon leaves were the glycosides of kaempferol and quercetin. Finally, fourteen antioxidants were quantitatively assessed. Offline LC×LC provided high peak capacity and separation; ECD enabled specific screening and detection of antioxidant components; and MS/MS provided excellent identification capability. In this study, the combination of the three approaches was utilized to screen for antioxidant components in persimmon leaves, with satisfactory findings. In conclusion, this technique is an effective means for rapid analysis of antioxidant components and quality control of medicinal plants, achieving rapid separation of congeners and facilitating more accurate qualitative and quantitative analyses.

Chinese herbal medicine Ginkgo biloba L. preparations for ischemic stroke: An overview of systematic reviews and meta-analyses

BACKGROUND

Ginkgo biloba L. preparations (GBLPs) are a class of Chinese herbal medicine used in the adjuvant treatment of ischemic stroke (IS). Recently, several systematic reviews (SRs) and meta-analyses (MAs) of GBLPs for IS have been published.

OBJECTIVE

This overview aims to assess the quality of related SRs and MAs.

SEARCH STRATEGY

PubMed, Embase, Cochrane Library, Web of Science, Chinese Biological Medicine, China National Knowledge Infrastructure, Wanfang, and Chinese Science and Technology Journals databases were searched from their inception to December 31, 2022.

INCLUSION CRITERIA

SRs and MAs of randomized controlled trials (RCTs) that explored the efficacy of GBLPs for patients with IS were included.

DATA EXTRACTION AND ANALYSIS

Two independent reviewers extracted data and assessed the methodological quality, risk of bias (ROB), reporting quality, and credibility of evidence of the included SRs and MAs using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2), Risk of Bias in Systematic Reviews (ROBIS), the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), and the Grading of Recommendations Assessment, Development and Evaluation (GRADE), respectively. Additionally, descriptive analysis and data synthesis were conducted.

RESULTS

Twenty-nine SRs/MAs involving 119 outcomes were included in this review. The overall methodological quality of all SRs/MAs was critically low based on AMSTAR 2, and 28 had a high ROB based on the ROBIS. According to the PRISMA statement, the reporting items of the included SRs/MAs are relatively complete. The results based on GRADE showed that of the 119 outcomes, 8 were rated as moderate quality, 24 as low quality, and 87 as very low quality. Based on the data synthesis, GBLPs used in conjunction with conventional treatment were superior to conventional treatment alone for decreasing neurological function scores.

CONCLUSION

GBLPs can be considered a beneficial supplemental therapy for IS. However, because of the low quality of the existing evidence, high-quality RCTs and SRs/MAs are warranted to further evaluate the benefits of GBLPs for treating IS. Please cite this article as: Meng TT, You YP, Li M, Guo JB, Song XB, Ding JY, Xie XL, Li AQ, Li SJ, Yin XJ, Wang P, Wang Z, Wang BL, He QY. Chinese herbal medicine Ginkgo biloba L. preparations for ischemic stroke: An overview of systematic reviews and meta-analyses. J Integr Med. 2024;22(2): 163-179.

A structural similarity networking assisted collision cross-section prediction interval filtering strategy for multi-compound identification of complex matrix by ion-mobility mass spectrometry

Ion mobility coupled with mass spectrometry (IM-MS), an emerging technology for analysis of complex matrix, has been facing challenges due to the complexities of chemical structures and original data, as well as low-efficiency and error-proneness of manual operations. In this study, we developed a structural similarity networking assisted collision cross-section prediction interval filtering (SSN-CCSPIF) strategy. We first carried out a structural similarity networking (SSN) based on Tanimoto similarities among Morgan fingerprints to classify the authentic compounds potentially existing in complex matrix. By performing automatic regressive prediction statistics on mass-to-charge ratios (m/z) and collision cross-sections (CCS) with a self-built Python software, we explored the IM-MS feature trendlines, established filtering intervals and filtered potential compounds for each SSN classification. Chemical structures of all filtered compounds were further characterized by interpreting their multidimensional IM-MS data. To evaluate the applicability of SSN-CCSPIF, we selected Ginkgo biloba extract and dripping pills. The SSN-CCSPIF subtracted more background interferences (43.24%∼43.92%) than other similar strategies with conventional ClassyFire criteria (10.71%∼12.13%) or without compound classification (35.73%∼36.63%). Totally, 229 compounds, including eight potential new compounds, were characterized. Among them, seven isomeric pairs were discriminated with the integration of IM-separation. Using SSN-CCSPIF, we can achieve high-efficient analysis of complex IM-MS data and comprehensive chemical profiling of complex matrix to reveal their material basis.

A fast stop-flow two-dimensional liquid chromatography tandem mass spectrometry and its application in food-derived protein hydrolysates

Food-derived bioactive peptides have many outstanding features like high safety, easy absorption, etc. However, explorations of the peptides are suffering from the limited knowledge of sample composition and low efficiency of separation techniques. In this work, a fast stop-flow two-dimensional liquid chromatography tandem mass spectrometry (2DLC-MS) was designed and constructed in-house. For chromatographic system optimization, the effects of column pairs and fraction transfer volumes on separation performance were studied. The pair of Protein BEH SEC and HSS T3 columns was found of high orthogonality. The peak capacity detected by the optimized 2DLC reached 1165 (for corn protein hydrolysates), indicating high resolving power. Moreover, the number of peptides identified from corn, soybean and casein protein hydrolysates reached as high as 8330, 8925 and 7215, respectively, demonstrating the high potential of the system. This would help reveal the peptide composition and facilitate the research on exploring bioactive peptides from food-derived protein hydrolysates.

Prinsepia utilis Royle leaf extract: Ameliorative effects on allergic inflammation and skin lesions in allergic contact dermatitis and polyphenolic profiling through UPLC-MS/MS coupled to chemometric analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Allergic contact dermatitis (ACD) is a common allergic inflammatory disease that is concomitant with skin swelling, redness, dry itching, and relapses. Prinsepia utilis Royle, a Chinese and Indian folk medicine, is rich in polyphenols with potential anti-inflammatory and skin-protective activities. However, the underlying mechanism of P. utilis leaf (PUL) in the treatment of ACD and its functional basis remains unclear.

AIM OF THE STUDY

This study is aimed to explore and reveal the active substances and mechanism of PUL against ACD.

MATERIALS AND METHODS

Hyaluronidase inhibitory assay and fluorescein isothiocyanate (FITC)-induced ACD mouse model were performed to assess the antiallergic effects of PUL in vitro and in vivo. Different solvents were applied to obtain multiple PUL extracts. The extracts were further tested for total phenolic content (TPC) and total flavonoid content (TFC) by using spectrophotometric assays. Polyphenolic profiles were analyzed by using ultrahigh-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-QTOF-MS/MS), and a simultaneous quantification method was established using UPLC-QTrap-MS/MS through multiple reaction monitoring (MRM) and applied to analyze the pharmacokinetics of the multiple major polyphenols of PUL in mice.

RESULTS

The water extract of PUL with the highest TPC/TFC exhibited the strongest antihyaluronidase effect (IC₅₀ = 231.93 μg/mL). In vivo assays indicated that the oral administration of PUL water extract dose-dependently attenuated ACD-like symptoms by decreased interleukin (IL)-4, IL-5, IL-13, IL-33, thymic stromal lymphopoietin, and IgE production, suppressed eosinophil and basophil secretion, and increasing the expression of tight junction (TJ) proteins (claudin-1 [CLDN-1] and occludin). Concomitantly, UPLC-QTOF-MS/MS analysis enabled the identification of 60 polyphenols and the pharmacokinetic parameters of seven quantified constituents of PUL were characterized. Four compounds, trans-p-coumaric acid 4-O-β-D-glucopyranoside (11), vicenin-2 (21), isoschaftoside (31), and kaempferol 3-O-(2″,6″-di-O-α-L-rhamnopyransoyl)-β-D-glucopyranoside (38) which displayed satisfactory pharmacokinetic features, were considered as potential effective substances in PUL.

CONCLUSIONS

PUL water extract ameliorated the allergic inflammation of ACD by repairing the epithelial barrier and alleviating Th2-type allergic inflammation. The anti-allergic effect of PUL is closely related to its phenolic substances, and compounds 11, 21, 31, and 38 were the active substances of PUL. It revealed that P. utilis could be developed as a new source of antiallergic agents for ACD therapy.

Offline two-dimensional normal-phase × reversed-phase liquid chromatography coupled with high-resolution mass spectrometry for comprehensive analysis of chemical constituents in Euphorbia kansui

Euphorbia kansui is the dried root of Euphorbia kansui T. N. Liou ex T.P. Wang. Its main chemical components are diterpenoids, triterpenes, and volatile oil. In this study, an offline two-dimensional (2D) normal-phase × reversed-phase liquid chromatography method coupled with quadrupole time-of-flight mass spectrometry was established to comprehensively analyze the chemical constituents in E. kansui. A total of 240 compounds were identified from the E. kansui extract, including 218 diterpenoids (77 known, 141 new), 16 known volatile oils, and six known triterpenes. The relationship between the structural characteristics and tandem mass spectroscopy fragments of diterpenoids was further analyzed. Based on the characteristic fragment ions, 141 new diterpenoids were determined as 118 ingenane diterpenoids and 23 jatrophane diterpenoids. The newly identified diterpenoids may provide lead compounds for drug discovery, improving the medicinal value of E. kansui.

Efficient strategies for preparative separation of iridoid glycosides and flavonoid glycosides from Hedyotis diffusa

Efficient strategies for the preparative separation of iridoid glycosides and flavonoid glycosides from Hedyotis diffusa using preparative high-performance liquid chromatography combined with appropriate pretreatment technologies were developed. Four fractions (Fr.1-1, Fr.1-2, Fr.1-3, and Fr.2-1) were firstly isolated from the crude extract of Hedyotis diffusa by column chromatography with C18, resin, and silica gel materials, respectively. Then, corresponding separation strategies were developed according to the polarity and chemical constituents. High-polar compounds of Fr.1-1 were purified by hydrophilic reversed-phase liquid chromatography and hydrophilic interaction liquid chromatography mode. The combination of C18 and phenyl columns realized the complementary separation of iridoid glycosides in Fr.1-2. Meanwhile, the improved selectivity caused by the change of organic solvent in the mobile phase was utilized to realize the purification of flavonoid glycosides in Fr.1-3 and Fr. 2-1. Finally, 27 compounds (purity > 95%) mainly involving nine iridoid glycosides and five flavonoid glycosides were obtained. A complete strategy was established for the separation of a complex sample with a wide polarity range, to jointly solve the problems of enrichment of target components and separation of structural analogs.

Systematical characterization of gypenosides in Gynostemma pentaphyllum and the chemical composition variation of different origins

Gynostemma pentaphyllum (Thunb.) Makino is an herbaceous plant of Cucurbitaceae family, which has been widely used as an herbal tea and traditional Chinese medicine. Since its saponins are similar to ginsenosides and have a wide range of activities, it has attracted wide interest. However, there are still a large number of unknown saponins that have not been isolated, especially some trace gypenosides. In the present study, a HILIC × RP offline two-dimensional liquid separation combined with a multimode data acquisition was developed for the systematical characterization of gypenosides. On top of the negative mode information, considering that saponins are prone to in-source fragmentations in positive ion mode, a precursor ion list data acquisition method was used for the targeted acquisition of multistage positive data. Reference herbal drug was taken as a golden sample to probe the chemical composition of G. pentaphyllum. The mixed sample of commercially available samples were also analyzed in parallel. Furthermore, the chemical compositions of commercially available samples from different sources were compared. In total, 1108 saponins were characterized, among which 588 were accurately characterized, with 574 identified in the reference herbal drug and 700 in the mixed commercially available samples. The commercially available samples showed great composition variation. These findings clarified the material basis and provided clues for quality control of G. pentaphyllum.

Effect of in vitro gastrointestinal digestion on the chemical composition and antioxidant properties of Ginkgo biloba leaves decoction and commercial capsules

In this study Ginkgo biloba leaves (GBL) decoction and commercial capsules were digested using an in vitro model. Thirty-six active compounds were identified and quantified by HPLC-ESI-MS analysis based on the MS/MS patterns (precursor ions and product ions) and retention times, in comparison with reference standards. Most compounds in GBL showed a significant decrease during intestinal digestion, with an exception of vanillic acid and biflavonoids. Bioaccessibility values of chemical compositions varied between decoction and capsules samples. Also, significant reductions of total flavonoids and total phenolic content was observed after in vitro digestion. Both, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazo-line-6-sulfonic acid (ABTS) scavenging capacity decreased after gastric digestion, but increased during intestinal digestion. Nevertheless, different behaviour was observed in reducing antioxidant power (FRAP) assay. Compared to the pH of digestion, the influence of digestive enzymes on the chemical composition and antioxidant activity of GBL was relatively minor. Overall, these results may help provide a valid foundation for further investigations on bioactive compounds and the pharmacodynamics of GBL.

Time-Series-Dependent Global Data Filtering Strategy for Mining and Profiling of Xenobiotic Metabolites in a Dynamic Complex Matrix: Application to Biotransformation of Flavonoids in the Extract of Ginkgo biloba by Gut Microbiota

Efficient characterization of xenobiotic metabolites and their dynamics in a changing complex matrix remains difficult. Herein, we proposed a time-series-dependent global data filtering strategy for the rapid and comprehensive characterization of xenobiotic metabolites and their dynamic variation based on metabolome data. A set of data preprocessing methods was used to screen potential xenobiotic metabolites, considering the differences between the treated and control groups and the fluctuations over time. To further identify metabolites of the target, an in-house accurate mass database was constructed by potential metabolic pathways and applied. Taking the extract of Ginkgo biloba (EGB) co-incubated with gut microbiota as an example, 107 compounds were identified as flavonoid-derived metabolites (including 67 original from EGB and 40 new) from 7468 ions. Their temporal metabolic profiles and regularities were also investigated. This study provided a systematic and feasible method to elucidate and profile xenobiotic metabolism.

Leaves, seeds and exocarp of Ginkgo biloba L. (Ginkgoaceae): A Comprehensive Review of Traditional Uses, phytochemistry, pharmacology, resource utilization and toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba L. (Ginkgoaceae) is a treasure species with high medicinal value. The Ming Dynasty "Compendium of Materia Medica" and Qing Dynasty "Bencao Fengyuan" in China recorded this herbal medicine can reduce phlegm, clear poison, treat diarrhea and frequent urination, etc. AIM OF THE STUDY: Until now, there is no painstakingly summarized review on leaves, seeds and exocarp of G. biloba simultaneously. This review will systematically summarize and compare current knowledge of G. biloba.

MATERIALS AND METHODS

Ample original publications related to traditional uses, phytochemistry, pharmacology, resource utilization and toxicity of G. biloba leaves, seeds and exocarp till the end of 2021 were searched and collected by using various literature databases, including China National Knowledge Infrastructure, PubMed, Elsevier, Springer, Google Scholar and Web of Science database.

RESULTS

According to classical Chinese herbal books and Chinese Pharmacopoeia, relieving cough, reducing phlegm, clearing poison and relieving diarrhea are the main pharmacological effects of G. biloba. The common chemical ingredients in different parts of G. biloba are flavonoids, terpenoids, phenolic acids, polysaccharides and endotoxin, etc. Among them, flavonoids and terpenoids are the main bioactive compounds in G. biloba leaves. Phenolic acids are the main bioactive compounds in G. biloba exocarp. G. biloba seeds are rich in nutritional ingredients, such as starch, adipose, protein, etc. Modern pharmacological studies showed that the crude extracts or compounds of G. biloba leaves, seeds and exocarp can be used for treating cardiovascular and cerebrovascular diseases, Alzheimer's disease, atherosclerosis, cancer, asthma, non-alcoholic fatty liver, diabetic complications and other diseases. In daily life, G. biloba seeds were usually used as raw material or additives for commodities, healthy food, drinks, even insecticides and antibacterial agents, etc. G. biloba leaves and seeds have been mainly applied for treating cardiovascular and cerebrovascular diseases, cough and asthma in clinical. However, endotoxins and ginkgolic acids have been identified as the dominating toxic ingredients in different parts of G. biloba. Besides, flavonoids and ginkgolides also have been proved to have toxicity recently.

CONCLUSIONS

This review systematically sums up and compares the traditional uses, phytochemistry, pharmacology, resource utilization and toxicity research progress of G. biloba leaves, seeds and exocarp for the first time. It will provide some comprehensive reference data and suggestions for future research on this herbal medicine.

The qualitative and quantitative profiling for quality assessment of Yinxing Mihuan Oral Solution and the stability study on the focused flavonol glycosides

Yinxing Mihuan Oral Solution (YMOS) has been widely applied for the treatment of coronary heart disease, angina pectoris, and cerebral ischemic disease in clinical practice. Nonetheless, the limited basic researches on quality analysis of YMOS remain a critical bottleneck that needs to be enhanced for better clinical applications. In this study, a total of 67 chemical components, including flavonoids, terpene lactones, nucleosides, etc., were tentatively characterized by ultra-high performance liquid chromatography tandem Q-Exactive Orbitrap high-resolution mass spectrometry, among which 34 compounds were further identified by comparison with reference substances. By adopting a methodologically validated method, we discovered that the quantitative estimate of multi-compounds in 22 batches of YMOS showed lot-to-lot consistency, and the additives in YMOS also met the corresponding regulations. Furthermore, five flavonol glycosides whose content presented a downward trend in the expired YMOS were focused. A systematic research on stability test focusing on the five targeted flavonol glycosides was performed under different temperatures and pH levels. It was found that ortho-diphenolic hydroxyl group on B-ring and the type of saccharide connected to 3-hydroxyl on C-ring play a pivotal role in the stability of the tested compounds. Subsequently, as the important compounds, ginkgolides A, B, and C in YMOS were simultaneously quantified with ultra performance liquid chromatography coupled with triple quadrupole mass spectrometry. In brief, this study performs a reliable chemical identification and provides a rapid and feasible method for the quality evaluation, which contributes to the in-depth investigation and safe application of YMOS for clinical uses.

Secondary or Specialized Metabolites, or Natural Products: A Case Study of Untargeted LC–QTOF Auto-MS/MS Analysis

The large structural diversity of specialized metabolites represents a substantial challenge in untargeted metabolomics. Modern LC–QTOF instruments can provide three- to four-digit numbers of auto-MS/MS spectra from sample sets. This case study utilizes twelve structurally closely related flavonol glycosides, characteristic specialized metabolites of plant tissues, some of them isomeric and isobaric, to illustrate the possibilities and limitations of their identification. This process requires specific software tools that perform peak picking and feature alignment after spectral deconvolution and facilitate molecular structure base searching with subsequent in silico fragmentation to obtain initial ideas about possible structures. The final assignment of a putative identification, so long as spectral databases are not complete enough, requires structure searches in a chemical reference database, such as SciFindern, in attempts to obtain additional information about specific product ions of a metabolite candidate or check its feasibility. The highlighted problems in this process not only apply to specialized metabolites in plants but to those occurring in other organisms as well. This case study is aimed at providing guidelines for all researchers who obtain data from such analyses but are interested in deeper information than just Venn diagrams of the feature distribution in their sample groups.

Chemical profiles of the active fraction from Prinsepia utilis Royle leaves and its anti-benign prostatic hyperplasia evaluation in animal models

Background

The Prinsepia utilis Royle leaves (P. utilis) is a folk herb used for benign prostatic hyperplasia (BPH) control by ethnic minorities for centuries in China with rich in resources. Our previous studies have confirmed the anti-BPH effect of its water extract (QCJ) and the active fraction (Fr. B) separated from the QCJ by animal test. The Fr. B from P. utilis should be a potential candidate for BPH control.

Methods

In this study, the chemical ingredients of Fr. B were identified by UPLC-QTOF-MS, and quantified by HPLC. Murine animal models were divided into 8 groups, Sham rats, BPH rats, BPH rats administered with finasteride (1 mg/kg), BPH rats administered with Pule’an (460 mg/kg), BPH rats administered with low, high dosage of QCJ (860 mg/kg, 2580 mg/kg respectively), BPH rats administered with low, high dosage of Fr. B (160 mg/kg, 480 mg/kg respectively). The expression of vascular endothelial growth factor (VEGF) in the prostate tissue of rats was tested, and serum levels of dihydrotestosterone (DHT), testosterone (T), estradiol (E2), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and total superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), malondialdehyde (MDA) in prostate homogenate were measured. One-way ANOVA followed by LSD was used for statistical analysis.

Results

The BPH rats treated by Fr. B exhibited significant reductions of VEGF and MDA levels, as well as significant increases of SOD, GSH-Px and CAT in the prostate tissue after 28 day administration (P < 0.05). Moreover, Fr. B significantly reduced DHT, DHT/E2 ratio, TNF-α, while increased T levels in serum of BPH rats (P < 0.05). UPLC-QTOF-MS analysis revealed 10 flavonoids as the key constituents of this fraction, which accounted for 54.96% of all substance of Fr. B. The relative contents of compound 1, 2 are 11.1%, 13% in Fr. B respectively.

Conclusions

These results indicated that the Fr. B obtained from P. utilis alleviated the symptoms of BPH rats through multiple mechanisms including reduction of DHT/E2 ratio, inhibition of growth factor, anti-inflammation and anti-oxidation, in which flavonoids might be the key constituents. It supported the hypothesis that the Fr. B should be further explored as a candidate for BPH patients.

Enrichment and separation of high-polar compounds from Saussurea obvallata using solid-phase extraction combining with offline two-dimensional liquid chromatography

The high-polar compounds from natural products are often used as medicines due to their good bioactivities. However, owing to the complexity and diversity of their structure, the separation of high-polar compounds is still a challenging work. For this, an efficient method for enrichment and separation of the high-polar compounds from Saussurea obvallata was developed. First, the target compounds were enriched from the total extract using a solid-phase extraction method. An offline two-dimensional liquid chromatography method was used for the separation of pure compounds from the enriched sample. After optimization of chromatographic conditions, high separation selectivity of target compounds was obtained on a polar-modified C18 column and a HILIC XAmide column. Hence, a two-dimensional reversed-phase × hydrophilic interaction liquid chromatography system was constructed and enlarged from the analytical level to the preparative level. In the first dimension, four fractions were obtained on the XCharge C18 column with a recovery rate of 71.2%. In the second-dimension preparation on the XAmide column, eight high-polar compounds with more than 96% purity were isolated. All compounds were isolated from Saussurea obvallata for the first time. The results demonstrated that this developed strategy is effective for preparative-scale isolation of high-polar compounds from natural products.

Reversed phase versus hydrophilic interaction liquid chromatography as first dimension of comprehensive two-dimensional liquid chromatography systems for the elucidation of the polyphenolic content of food and natural products

Comprehensive two-dimensional liquid chromatography is a well-established method for the unraveling of very complex real-world samples. With regard to food and natural products such a technique turned out to be a very promising approach due to its high resolving power and improved identification capability, especially in combination with mass spectrometry. In this context, polyphenols comprise a particular complex class of bioactive compounds, due to their nature and content in commonly consumed foodstuffs, making their analysis challenging. The present contribution shows an overview of the two commonly employed approaches used for polyphenol analysis, viz. RP-LC × RP-LC and HILIC × RP-LC. Furthermore, the latest implementations as well as limitations and future perspectives are critically reported.

A simple and effective method for the preparation of high-purity shikimic acid from chromatography wash effluent of Ginkgo biloba leaf extract by macroporous resin considering the effect of varying feed solution compositions

OBJECTIVES

The present study investigated the feasibility of preparing high-purity shikimic acid (SA) from the chromatography wash effluent of Ginkgo biloba leaf extract by macroporous resin.

METHODS

First, static/dynamic adsorption and desorption were conducted to screen out the optimal resin. Second, the key parameters of the chromatographic process were optimised with face-centred central composite design (CCD). Third, wash effluent indices were measured, different batches of wash effluent were used to prepare SA under the optimised parameters, and the effect of varying feed solution compositions on final products was investigated.

KEY FINDINGS

It was found that the final purity and recovery rate of SA prepared with ADS-21 resin were not lower than 70 and 60%, respectively, when the purity of SA in the wash effluent was higher than 21.4%. The quality of the final product can be predicted based on the properties of wash effluent.

CONCLUSIONS

The proposed method could not only provide a simple, green and promising approach for the large-scale purification of SA from wash effluent but also be used to develop process intermediate quality standards for other natural products.

Advances in the chemical constituents and chemical analysis of Ginkgo biloba leaf, extract, and phytopharmaceuticals

Ginkgo biloba leaf (GBL) is an important botanical drug that can be used for treating many diseases. This review summarizes the reported chemical constituents from GBL or Ginkgo biloba extract (GBE) to date, as well as the recent advances in the extraction, purification, qualitative and quantitative analysis methods (from 2015 to 2020). To date, about 110 flavonoids have been reported to have unambiguous structures, including flavonol and its glycosides, flavone and its glycosides, flavanone and its glycosides, isoflavone and its glycosides, flavan-3-ols, bioflavonoids, and biginkgosides. In recent years, in addition to new flavonoids, new terpenoids and lignan have been also isolated from GBL. Further, several extraction and purification methods have been described and compared. Quantitative analysis of the constituents have been mainly carried out by high-performance liquid chromatography with different detector methods. Many studies have focused on variations of compounds contents in GBL from different regions, tree ages, or collection times, which provide references for the selection of GBL. Liquid chromatography-mass spectrometry coupled with activity assay methods were used to on-line screen the bioactive compounds from GBL or its phytopharmaceuticals. The application of other analytical technologies such as MS imaging, supercritical fluid chromatography, capillary electrophoresis, quantitative nuclear magnetic resonance, and spectroscopy, has also been discussed. This review of the chemical constituents and analytical methods of Ginkgo will provide a reference for the research on the quality control and discovery of effective constituents for GBL and its related phytopharmaceuticals.

Characterization of four major degradation products in metformin by 2D LC-QTOF/MS/MS

A two-dimensional liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(2D LC-QTOF/MS/MS) method was developed for the characterization of four major degradation products in metformin under acidic, basic, oxidative and 6 months accelerated conditions. A CAPCELL PAK SCX TYPE UG80 column(5 μm, 4.6 × 150 mm) was applied using 17 g/L ammonium dihydrogen phosphate adjusted to pH 3.0 by phosphoric acid as the mobile phase at a flow rate of 1.0 mL/min in the first dimension (D1), and the collected fractions further flowed to a Waters Xbridge C18 column(5 μm, 4.6 mm × 250 mm) with a mobile phase consisting of 0.1 % formic acid and acetonitrile (95:5 v/v) at the same flow rate as the second dimension(D2). Two of the impurities were never reported as the degradation of metformin, and all the four structures, as well as the proposed fragmentation patterns were inferred in this research.

Green and enhanced extraction of coumarins from Cortex Fraxini by ultrasound-assisted deep eutectic solvent extraction

Green and enhanced extraction of bioactive ingredients from medicinal plants has become a hot research field, and deep eutectic solvents have been considered as a novel kind of sustainable solvents in the extraction process. In this study, hydrogen bond acceptor (choline chloride, etc.) and hydrogen bond donor (l-malic acid, etc.) were used to prepare different kinds of deep eutectic solvents to extract coumarins from Cortex Fraxini. The extraction conditions, including the composition and moisture content of deep eutectic solvents, extraction time, and liquid-solid ratio, were systematically optimized basing on the extraction yield of coumarins. To further investigate the extraction mechanism, Fourier transform infrared spectroscopy was performed, and the microstructures of Cortex Fraxini powders were observed before and after extraction using scanning electron microscope. Results showed that the novel ultrasound-assisted extraction with conditions of deep eutectic solvent containing betaine/glycerin (1:3), aqueous solution (20%), solid-liquid ratio (15 mg/mL), and extraction time (30 min) exhibited the best extraction yields for the four target coumarins and much better extraction efficiency than with conventional solvent extractions. This suggests that the new ultrasound-assisted deep eutectic solvent extraction could be used as a green and high-efficient approach for extraction of the main coumarins from Cortex Fraxini.

Simultaneous quantification of oestrogens and androgens in the serum of patients with benign prostatic hyperplasia by liquid chromatography-Tandem mass spectrometry

Benign prostate hyperplasia (BPH) is a common disease in elderly men. It has been found that the occurrence of BPH was closely related to dysregulated steroid hormones. Here, a rapid, sensitive, accurate and specific method for the quantitative profiling of five androgens in man serum was developed and validated by the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using this method, dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T), androsterone (A), dihydrotestosterone (DHT), oestrone (E1) and oestradiol (E2) were quantified in serum from man with and without BPH. BPH patients were characterised by the decreases in DHEA, A4 and T as well as increases in DHT, E2 and E1 in serum. Meanwhile, DHEA and DHT in serum were screened as sensitive biomarkers of BPH patients. This study will provide a new perspective of dysregulated steroid hormones for the diagnosis and prevention of BPH.

A sensitive and selective multiple reaction monitoring mass spectrometry method for simultaneous quantification of flavonol glycoside, terpene lactones, and biflavonoids in Ginkgo biloba leaves

In this study, an efficient and sensitive UHPLC-QQQ-MS/MS (MRM) analytical strategy was established firstly for simultaneous determination of 11 components, including 3 original flavonol glycoside, 4 terpene lactones and 4 biflavonoids in Ginkgo biloba leaves. The validated strategy exhibited proper linearity (R² ≥0.99) in the range of 0.5-125 μg/mL, and intra and inter-day precision were lower than 4.09% and 4.80%, respectively. Limit of detection (LOD) and quantification (LOQ) were calculated, ranging from 0.2-4.6 ng/mL, with repeatability values between 1.98% and 4.48%. The average recoveries were all in the range of 98.45-106.67% with RSD (n = 3) for the related compounds. Subsequently, the proposed method was used for the analysis of Ginkgo biloba leaves during leaf senescence. Results showed the dominant flavonol glycosides were kaempferol-3-O-rutinoside and isorhamnetin-3-O-rutinoside, the level of terpene lactones and biflavonoids reached the highest in the latest harvest samples. Compared with conventional detection method, the present method could directly analyze original flavonol glycoside without acid hydrolysis process and terpene lactones without the ELSD in a high sensitivity. Moreover, the biflavonoids in Ginkgo biloba leaves were also simultaneously quantified. The results demonstrated that the developed method was accurate, sensitive and reliable for simultaneous quantification of multi-components in Ginkgo biloba leaves, and this study should be significant for the comprehensive utilization and development of Ginkgo biloba resources.

Chemical Profiling and Comparison of Sangju Ganmao Tablet and Its Component Herbs Using Two-Dimensional Liquid Chromatography to Explore Compatibility Mechanism of Herbs

Sangju Ganmao tablet (SGT), a well-known Chinese patent medicine used to treat cold symptoms, is made from eight herbal medicines. In this study, an off-line hydrophilic interaction × reversed-phase two-dimensional liquid chromatography (HILIC × RP 2D-LC) method was developed to comprehensively separate the chemical constituents of SGT. Through optimization of the experimental conditions, a total of 465 peaks were finally detected in SGT, and the structures of 54 selected compounds were fully identified or tentatively characterized by quadrupole time-of-flight mass spectrometry (qTOF-MS) analysis. The established 2D-LC analysis showed high orthogonality (63.62%) and approximate 11-fold improvement in peak capacity (2399 and 1099, obtained by two calculation methods), in contrast to conventional one-dimensional RPLC separation. The eight component herbs of SGT were also respectively separated by using the 2D-LC system, and we found that a total of 12 peaks detected in SGT were not discovered in any component herbs. These newly generated chemical constituents would benefit better understanding of the compatibility mechanism of the component herbs. The strategy established in this study could be used for systematic chemical comparison of SGT and its component herbs, which contributes to exploration of herbal compatibility mechanism.

The application of on-line two-dimensional liquid chromatography (2DLC) in the chemical analysis of herbal medicines

Herbal medicines are complicated chemical systems containing hundreds of small molecules of various polarities, structural types, and contents. Thus far, the chromatographic separation of herbal extracts is still a big challenge. Two-dimensional liquid chromatography (2DLC) has become an attractive separation tool in the past few years. Particularly, a lot of attention has been paid to on-line 2DLC. In this review, we aim to give an overview on applications of on-line 2DLC in the chemical analysis of herbal medicines since 2010. Firstly, classification and general configurations of on-line 2DLC were briefly introduced. Then, we summarized main applications in herbal medicines of heart-cutting 2DLC (LC-LC), comprehensive 2DLC (LC × LC), and their combinations, with emphasis on LC × LC. Mass spectrometry is the most popular detector coupled with 2DLC, which allows sensitive and accurate structural characterization of herbal compounds. Finally, future developments in on-line 2DLC techniques were also discussed.

Polarity-extended quantitative analysis of bear bile and its analogues using serially coupled reversed phase-hydrophilic interaction liquid chromatography-tailored multiple reaction monitoring

Polarity-extended quantitative analysis of bear bile and its analogues was achieved using serially coupled reversed phase-hydrophilic interaction liquid chromatography-tailored multiple reaction monitoring.