Preparative isolation and purification of seven main antioxidants from Eucommia ulmoides Oliv. (Du-zhong) leaves using HSCCC guided by DPPH-HPLC experiment

Advancing profiling of secondary antioxidant metabolites in Allium cepa PDO leaf extract: Online comprehensive two-dimensional liquid chromatography with high-resolution mass spectrometry and pre-column DPPH assay

The food and agricultural processing industries generate significant amounts of phenolic-rich by-products, which hold potential as natural antioxidant sources for a wide range of applications, including functional ingredients and nutraceutical formulations. Allium cepa leaves represent a promising source of bioactive compounds. However, due to the complexity of their chemical composition, advanced analytical techniques are required to fully characterize the secondary metabolite profile and identify specific phytochemical classes or fractions with high nutraceutical potential. In this context, an online comprehensive two-dimensional liquid chromatography (LC×LC) approach was developed and optimized for the in-depth characterization of the phytochemical profile of Allium cepa PDO leaf extract. Key parameters in both dimensions, including flow rate, stationary phase chemistry, and mobile phase composition, were investigated to enhance peak capacity and orthogonality. The optimized method combined reversed phase in both dimension (RP-LC×RP-LC), offering high orthogonality (A0: 70.46 %) and peak capacity (nc: 1788.88). and significantly improving the separation of multiple secondary metabolite classes by effective employment of the 2D separation space. Further hyphenation with high-resolution mass spectrometry (HRMS), enhanced compound annotation compared to mono-dimensional (1D-LC) techniques. A total of 147 compounds were tentatively annotated belonging to multiple classes such as flavonoids, saponins, phenylpropanoids, isoprenoids, terpenes, dipeptides, fatty acids, and lipids. Additionally, the antioxidant activity of Allium cepa leaf extract was assessed by coupling a pre-column 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with the LC×LC-DAD-HRMS platform. This integrated approach enabled the identification of individual contributions of flavonoids, isoprenoids, and phenylpropanoids to radical scavenging activity. The method allowed an in-depth exploration of Allium cepa phytochemical profile, demonstrating to hold significant potential for the standardization of antioxidant biomarkers, with promising applications in the nutraceutical industry.

Separation and Purification of Ginsenosides and Flavonoids in From the Leaves and Stems of Panax quinquefolium by High-Speed Countercurrent Chromatography and Online-Storage Inner-Recycling Countercurrent Chromatography

Study aimed to isolate and purify compounds from the stems and leaves of Panax quinquefolius. By employing a highly innovative separation technique that combined multistage countercurrent chromatography (MRCC), high-speed countercurrent chromatography (HSCCC), and an advanced online-storage inner-recycling countercurrent chromatography (OS-IRCCC) mode for the first time, 12 compounds were successfully isolated, including 10 ginsenosides and 2 flavonoids. First, the crude extract was fractionated into five parts using D101 MRCC, with HPLC analysis revealing that 40% and 60% ethanol eluate contained the highest compound diversity. Overall, 40% ethanol eluate was separated using the solvent system of EtOAc/n-BuOH/H2O (2:1:3, v/v), whereas 60% ethanol eluate underwent traditional countercurrent chromatography coupled with OS-IRCCC separation using the solvent system of methyl tert-butyl ether (MTBE)/n-BuOH/ACN/H2O (4:2:3:8, v/v). Ultimately, various compounds were obtained, including kaempferol 3-O-β-d-glucopyranosyl-(1 → 2)-β-d-galactopyranosyl-7-O-α-l-rhamnopyranoside (13.2 mg), ginsenoside Rc (7.4 mg), 20(R)-ginsenoside Rh1 (7.2 mg), ginsenoside Re (12.3 mg), kaempferol 3-O-β-d-glucopyranosyl-(1 → 2)-β-d-galactopyranoside (14.1 mg), ginsenoside Rb1 (8.2 mg), ginsenoside Rb2 (17.5 mg), ginsenoside Rb3 (27.3 mg), ginsenoside Rg1 (13.3 mg), ginsenoside Rg2 (9.7 mg), ginsenoside Rd (11.4 mg), and pseudo-ginsenoside F11 (16.7 mg). This research highlights the efficacy of the novel separation technique in isolating and purifying valuable compounds from P. quinquefolius stems and leaves.

Optimization of ultrasonic-assisted deep eutectic solvent extraction, characterization, and bioactivities of polysaccharides from Eucommia ulmoides

For the valorization of Eucommia ulmoides (EU) for the functional food industry, the process of ultrasonic-assisted deep eutectic solvent (DES) extraction of EU polysaccharides (EUP) was optimized by response surface methodology. After response surface analysis and experimental verification, the optimum extraction conditions were as follows: the molar ratio of choline chloride to oxalic acid was 0.9:1, the water content of DES was 40.28%, the ratio of material to liquid was 1:22 g/mL, the time was 90 min, and the power was 320 W. The extraction rate of EUP was 1.71%, which was higher than the extraction rate of 0.75% by ultrasonic water extraction under the same conditions, and the optimization effect was better. After DEAE column gradient elution and Sephadex G-75 gel column chromatography, the elution curve and a refined polysaccharide (EUP-1) were obtained. The IC50 values of EUP-1 against α-glucosidase and α-amylase were 0.091 and 0.011 mg/mL. The IC50 values of EUP-1 on DPPH and ABTS·+ scavenging were 0.065 and 0.065 mg/mL. The monosaccharide composition of EUP-1 was analyzed as mannose, rhamnose, glucuronic acid, and galacturonic acid in the following molar ratio: 1.00: 1.28: 1.53: 1.88.

Extraction, Characterization, and Antioxidant Activity of Eucommia ulmoides Polysaccharides

Herein, the ultrasound-assisted extraction conditions affecting the yield of EUPS (Eucommia ulmoides polysaccharide) were analyzed using a Box-Behnken response surface design. The alleviation effect of EUPS on diquat-induced oxidative stress in mice was also studied. A maximum EUPS yield of 2.60% was obtained under the following optimized conditions: an extraction temperature of 63 °C, extraction time of 1 h, and ratio of liquid to raw materials of 22:1. EUPS exhibited strong 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging ability (87.05%), 2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical-scavenging ability (101.17%), and hydroxyl radical-scavenging ability (62.92%). The administration of EUPS increased the activities of superoxide dismutase, catalase, and glutathione peroxidase and decreased malondialdehyde levels in the livers of mice exposed to diquat. EUPS may inhibit the downregulation of NAD(P)H:quinoneoxidoreductase 1 and heme oxygenase 1 mRNA expression in the livers of diquat-administered mice through the Nrf2-Keap1 signaling pathway. Moreover, the abundance of Firmicutes and Ligilactobacillus was enhanced, whereas that of Helicobacter decreased in the gut of the remaining groups of mice compared with that of the diquat-treated mice. Therefore, EUPS exhibited an antioxidant effect and improved oxidative stress and intestinal flora abundance in mice.

Identification of procyanidins as α-glucosidase inhibitors, pancreatic lipase inhibitors, and antioxidants from the bark of Cinnamomum cassia by multi-bioactivity-labeled molecular networking

This study examined the suppressive effects of 16 selected plant-based foods on α-glucosidase and pancreatic lipase and their antioxidant properties. Among these, the bark of Cinnamomum cassia (Cinnamon, WLN-FM 15) showed the highest inhibitory activity against α-glucosidase and the highest antioxidant activity. Additionally, WLN-FM 15 showed promising results in the other tests. To further identify the bioactive constituents of WLN-FM 15, a multi-bioactivity-labeled molecular networking approach was used through a combination of GNPS-based molecular networking, DPPH-HPLC, and affinity-based ultrafiltration-HPLC. A total of nine procyanidins were identified as antioxidants and inhibitors of α-glucosidase and pancreatic lipase in WLN-FM 15. Subsequently, procyanidins A1, A2, B1, and C1 were isolated, and their efficacy was confirmed through functional assays. In summary, WLN-FM 15 has the potential to serve as a functional food ingredient with the procyanidins as its bioactive constituents. These results also suggest that the multi-bioactivity-labeled molecular networking approach is reliable for identifying bioactive constituents in plant-based foods.

Rapid screening and target-guided isolation of antioxidants from German chamomile by 2,2-diphenyl-1-picrylhydrazyl-ultra-high-performance liquid chromatography-mass spectrometry coupled with off-line two-dimensional high-speed countercurrent chromatography

German chamomile is one of the most effective herbal elements used in anti-allergic products and as an antioxidant. Herein, the antioxidant activity of different extract fractions of German chamomile was initially evaluated using an off-line 2,2-diphenyl-1-picrylhydrazyl spectrophotometric assay. The ethyl acetate extract demonstrated the highest efficacy in scavenging free radicals. Based on this, a rapid screening and separation method using ultra-high-performance liquid chromatography combined with the 2,2-diphenyl-1-picrylhydrazyl assay was implemented to identify antioxidants in the ethyl acetate fraction of German chamomile flowers. Ten potential radical scavengers were tentatively screened from German chamomile using a target-guided isolating approach with off-line two-dimensional high-speed countercurrent chromatography and the structures of the compounds were analyzed and identified. Ultimately, 10 radical scavengers were obtained from the ethyl acetate extract with a purity quotient exceeding 90%. The results demonstrated the effectiveness and reproducibility of this method for isolating potential antioxidants from complex mixtures in a targeted manner. This strategy can be applied to the target-guided isolation of complex mixtures of natural products with broad K-values and similar structures.

Isoquercitrin promotes ferroptosis and oxidative stress in nasopharyngeal carcinoma via the AMPK/NF-κB pathway

Isoquercitrin has been discovered with various biological properties, including anticancer, anti-inflammation, antioxidation, and neuroprotection. The aim of this study is to explore the efficacy of isoquercitrin in nasopharyngeal carcinoma (NPC) and to disclose its potential regulating mechanisms. CNE1 and HNE1 cells were treated with various concentrations of isoquercitrin. Ferrostatin-1 (Fer-1, a ferroptosis inhibitor) and alpha-lipoic acid (ALA, an activator of the AMP-activated protein kinase [AMPK] pathway) treatments were conducted to verify the effects of isoquercitrin, respectively. Cell viability, proliferation, reactive oxygen species (ROS) generation, and lipid peroxidation were determined, respectively. GPX4 expression and ferroptosis- and pathway-related protein expression were measured. A xenograft tumor model was constructed by subcutaneously inoculating CNE1 cells into the middle groin of each mouse. We found that the IC50 values of CNE1 and HNE1 cells were 392.45 and 411.38 μM, respectively. CNE1 and HNE1 viability and proliferation were both markedly reduced with the increasing concentration of isoquercitrin. ROS generation and lipid peroxidation were both enhanced with declined ferroptosis-related markers under isoquercitrin treatment. The nuclear factor kappa B (NF-κB) pathway, the AMPK pathway, and the interleukin (IL)-1β expression were all markedly suppressed by isoquercitrin. Moreover, isoquercitrin restrained the tumor growth and enhanced lipid peroxidation and ferroptosis in vivo. Interestingly, both Fer-1 and ALA treatments distinctly offset isoquercitrin-induced effects in vitro and in vivo. These findings indicated that isoquercitrin might enhance oxidative stress and ferroptosis in NPC via AMPK/NF-κB p65 inhibition.

Research Progress of Eucommia ulmoides Oliv and Predictive Analysis of Quality Markers Based on Network Pharmacology

Du Zhong is a valuable Chinese medicinal herb unique to China. It is a national second- class precious protected tree, known as "plant gold", which has been used to treat various diseases since ancient times. The main active ingredients are lignans, phenylprophetons, flavonoids, iridoids and steroids and terpenoids, which have pharmacological effects such as lowering blood pressure, enhancing immunity, regulating bone metabolism, protecting nerve cells, protecting liver and gallbladder and regulating blood lipids. In this paper, a comprehensive review of Eucommia ulmoides Oliv. was summarized from the processing and its compositional changes, applications, chemical components, pharmacological effects, and pharmacokinetics, and the Q-marker of Eucommia ulmoides Oliv. is preliminarily predicted from the aspects of traditional efficacy, medicinal properties and measurability of chemical composition, and the pharmacodynamic substance basis and potential Q-marker of Eucommia ulmoides Oliv. are further analyzed through network pharmacology. It is speculated that quercetin, kaempferol, β-sitosterol, chlorogenic acid and pinoresinol diglucoside components are selected as quality markers of Eucommia ulmoides Oliv., which provide a basis for the quality control evaluation and follow-up research and development of Eucommia ulmoides Oliv.

Target-guided isolation and purification of cyclooxygenase-2 inhibitors from Meconopsis integrifolia (Maxim.) Franch. by high-speed counter-current chromatography combined with ultrafiltration liquid chromatography

Meconopsis integrifolia (Maxim.) Franch. is used extensively in traditional Tibetan medicine for its potent anti-inflammatory properties. In this study, six cyclooxygenase-2 (COX-2) inhibitors were purified from M. integrifolia using high-speed counter-current chromatography guided by ultrafiltration liquid chromatography (ultrafiltration-LC). First, ultrafiltration-LC was performed to profile the COX-2 inhibitors in M. integrifolia. The reflux extraction conditions were further optimized using response surface methodology, and the results showed that the targeted COX-2 inhibitors could be well enriched under the optimized extraction conditions. Then the six target COX-2 inhibitors were separated by high-speed countercurrent chromatography with a solvent system composed of ethyl acetate/n-butanol/water (4:1:4, v/v/v. Finally, the six COX-2 inhibitors, including 21.2 mg of 8-hydroxyluteolin 7-sophoroside, 29.6 mg of 8-hydroxyluteolin 7-[6'''-acetylallosyl-(1→2)-glucoside], 42.5 mg of Sinocrassoside D3, 54.1 mg of Hypolaetin 7-[6'''-acetylallosyll-(l→2)-3''-acetylglucoside, 30.6 mg of Hypolaetin 7-[6'''-acetylallosyll-(l→2)-6''-acetylglucoside and 17.8 mg of Hypolaetin were obtained from 500 mg of sample. Their structures were elucidated by 1 H-NMR spectroscopy. This study reveals that ultrafiltration-LC combined with high-speed counter-current chromatography is a robust and efficient strategy for target-guided isolation and purification of bioactive molecules. It also enhances the scientific understanding of the anti-inflammatory properties of M. integrifolia but also paves the way for its further medicinal applications.

Dietary Eucommia ulmoides leaf extract improves laying performance by altering serum metabolic profiles and gut bacteria in aged laying hens

The leaves of Eucommia ulmoides are rich in bioactive constituents that have potential gastrointestinal benefits for animals. In aged laying hens, intestinal health issues contribute to a significant decline in egg-laying capacity during intermediate and later stages. It remains unclear whether E. ulmoides leaf extract (ELE) can improve intestinal health and enhance egg production in elderly laying hens, and the underlying mechanisms are yet to be elucidated. Therefore, we conducted a study with 480 laying hens (65 weeks old) randomly allocated into four groups: a control group fed with the basal diet, and three treatment groups supplemented with 500, 1,000, and 2,000 mg/kg of ELE, respectively. The primary active constituents of ELE include flavonoids, polysaccharides, terpenoids, and phenolic acids. Dietary supplementation with ELE at 1,000 mg/kg (ELE1000) significantly improved laying performance and egg quality compared to the other groups. ELE1000 stimulated the maturation of intestinal epithelial cells, increased villus height, and reduced crypt depth. It also influenced the levels of proteins associated with tight junctions (claudin-1 and claudin-2) and intestinal inflammatory factors (IL-6, IL-1β, and IL-2) in different intestinal sections. Integrative analysis of serum metabolomics and gut microbiota revealed that ELE1000 improved nutrient metabolism by modulating amino acid and ubiquinone biosynthesis and influenced the abundance of intestinal microbiota by enriching pivotal genera such as Bacteroides and Rikenellaceae_RC9_gut_group. We identified 15 metabolites significantly correlated with both gut microbiota and laying performance, e.g., DL-methionine sulfoxide, THJ2201 N-valerate metabolite, tetracarbonic acid, etc. In conclusion, ELE1000 improved laying performance in elderly laying hens by affecting intestinal morphology, barrier function, microbiota, and serum metabolite profiles. These findings suggest that ELE can be a beneficial feed additive for extending the peak producing period in aged laying hens.

Target-Guided Isolation and Purification of Antioxidants from Urtica laetevirens Maxim. by HSCCC Combined with Online DPPH-HPLC Analysis

Urtica laetevirens Maxim. is used extensively in traditional Chinese medicine (TCM) for its potent antioxidative properties. In this study, three antioxidants were purified from U. laetevirens. using HSCCC guided by online DPPH-HPLC analysis. Firstly, the online DPPH-HPLC analysis was performed to profile out the antioxidant active molecules in U. laetevirens. The ultrasonic-assisted extraction conditions were optimized by response surface methodology and the results showed the targeted antioxidant active molecules could be well enriched under the optimized extraction conditions. Then, the antioxidant active molecules were separated by high-speed countercurrent chromatography ethyl acetate/n-butanol/water (2:3:5, v/v/v) as the solvent system. Finally, the three targets including 16.8 mg of Isovitexin, 9.8 mg of Isoorientin, and 26.7 mg of Apigenin-6,8-di-C-β-d-glucopyranoside were obtained from 100 mg of sample. Their structures were identified by 1H NMR spectroscopy.

Preparation of Isoquercetin From Toona sinensis by Liquid-Liquid-Refining Extraction And Consecutive Counter-Current Chromatography

A high-speed counter-current chromatographic (HSCCC) method using ethyl acetate-water as solvent system was established to separate isoquercetin from Toona sinensis. In an HSCCC single separation, the sample sizes of ethanol extract were optimized from 203 to 1200 mg. The results showed that the yield of the target compound increased from 4 to 26 mg, and the corresponding purity decreased from 93.30 to 81.82%. To further improve the yield and purity, liquid-liquid-refining extraction was introduced to pretreat the ethanol extract and enrich the target compound. The ethanol extract was extracted with n-hexane-ethyl acetate-method-water (1:5:1:5, v/v) and ethyl acetate-water in turn to remove the low-polarity and high-polarity impurities and obtain the crude sample. Under the similar conditions, 85.25 mg of the target compound with the purity of 95.12% was separated from 240 mg of the crude sample. Subsequently, a consecutive HSCCC was developed to obtain 257 mg of the target compound from 720 mg of crude sample, which was equivalent to 14.4 g of ethanol extract. This method improved the purity of the target compound, but more importantly, the sample size can reach 12 times of the maximum sample size of the ethanol extract in a single run.

Quality Marker Discovery and Quality Evaluation of Eucommia ulmoides Pollen Using UPLC-QTOF-MS Combined with a DPPH-HPLC Antioxidant Activity Screening Method

Pollen, as an important component of Eucommia ulmoides (EUP), is rich in nutrients and is receiving increasing attention. At present, there are no reports on research related to the chemical composition and quality standards of EUP, and there are significant quality differences and counterfeit phenomena in the market. This study used a UPLC-QTOF-MS system to identify 49 chemical components in EUP for the first time. In the second step, 2,2-diphenyl-1-picrylhydrazyl (DPPH)-HPLC antioxidant activity screening technology was used to identify the main active components of EUP, quercetin-3-O-sophoroside (QSH), quercetin-3-O-sambubioside (QSB), and quercetin 3-O-neohesperidoside (QNH), and their purification, preparation, and structure identification were carried out. Third, molecular docking was used to predict the activity of these components. Fourth, the intracellular ROS generation model of RAW264.7 induced by H2O2 was used to verify and evaluate the activity of candidate active ingredients to determine their feasibility as Q-markers. Finally, a quality control method for EUP was constructed using the three selected components as Q-markers. The identification of chemical components and the discovery, prediction, and confirmation of characteristic Q-markers in EUP provide important references for better research on EUP and the effective evaluation and control of its quality. This approach provides a new model for the quality control of novel foods or dietary supplements.

Eucommia bark/leaf extract improves HFD-induced lipid metabolism disorders via targeting gut microbiota to activate the Fiaf-LPL gut-liver axis and SCFAs-GPR43 gut-fat axis

BACKGROUND

The bark of Eucommia ulmoides (a perennial deciduous tree termed eucommia hereafter) has anti-hyperlipidemia effects due to its bioactive components. However, the slow growth of eucommia bark leads to a deficit in this resource. Studies have shown that eucommia leaf has bioactive components similar to those of eucommia bark and anti-hyperlipidemia effects. At present, the strength of the anti-hyperlipidemia effect of eucommia bark and eucommia leaf has not been reported. Their interaction with the gut microbiota and the mechanism by which the gut microbiota exerts anti-hyperlipidemia effects are unclear.

PURPOSES

Through fecal microbiota transplantation (FMT) experiments, this study aimed to investigate the mechanism by which fecal bacteria suspensions containing chlorogenic acid (CGA), eucommia bark extract (EBE), and eucommia leaves extract (ELE) improve high-fat diet (HFD)-induced lipid metabolism disorders. Difference in anti-hyperlipidemia effects between EBE and ELE and exploring an eucommia bark substitute to improve the sustainable utilization of eucommia were also evaluated.

RESULTS

EBE and ELE contain eight identical bioactive ingredients, and fecal bacteria suspensions containing EBE and ELE significantly improved HFD-induced lipid metabolism disorders and elevated blood glucose levels. The fecal bacteria suspension of healthy mice containing CGA, EBE, and ELE significantly reduced the relative abundance of Erysipelothrichaceae and Ruminococcaceae and promoted short chain fatty acids (SCFAs) production thereby activating the expression of the SCFA. G protein-coupled receptor 43 (GPR43) gene in colon and epididymal fat tissues. In addition, fecal bacteria suspensions of healthy mice containing CGA, EBE, or ELE significantly activated fasting-induced adipose factor (Fiaf) gene expression in colon tissue and inhibited the secretion of lipoprotein lipase (LPL) in liver tissue, thereby inhibiting the synthesis of triglycerides (TG). Changed in the Erysipelotrichaceae and Ruminococcaceae relative abundances were significantly correlated with these target genes. Thus, regulating the abundance of the Erysipelotrichaceae and Ruminococcaceae could serve as a potential target for the role of fecal bacteria suspensions of healthy mice containing CGA, EBE, or ELE in the Fiaf-LPL gut-liver axis and SCFAs-GPR43 gut-fat axis. In addition, regarding HFD-induced lipid metabolism disorders and gut microbiota structural disorders, we found no significant difference between ELE and EBE.

CONCLUSIONS

Our FMT experiments evidenced that EBE and ELE improve lipid metabolism disorders by regulating the gut microbiota, providing a new pathway for treating hyperlipidemia using eucommia dietary therapy. There was no significant difference in the anti-hyperlipidemia effects of ELE and EBE; thus, eucommia leaf could replace eucommia bark in traditional Chinese medicine, so as to achieve a sustainable utilization of eucommia resources.

An all-cellulose sponge with a nanofiller-assisted hierarchical cellular structure for fruit maintaining freshness

Cellulose sponges with compressibility and resilience are an ideal packaging material for fruits with fragile skin. Here, a soft and elastic all-cellulose sponge (CS) with a hierarchical cellular structure was fabricated, where the long molecular chain cellulose constructed major pores, the cellulose at nanoscale acted as an elastic nanofiller to fill the gaps of long molecular chain cellulose fibers and constructed minor pores. With these two kinds of pores, this structure can absorb strain hierarchically. The sponge can protect fruits from mechanical damage when dropped or repeated vibration. Furthermore, the CS modified with chlorogenic acid (C-CGAS) had excellent antibacterial and antifungal abilities. Therefore, C-CGAS could extend the storage time of strawberries to 18 days without any microbial invasion, which is the longest storage time reported thus far. This study provides a new idea for the preparation of polymer sponges and a new design for the development of antimicrobial packaging materials.

pH-Responsive epitope-imprinted magnetic nanoparticles for selective separation and extraction of chlorogenic acid and caffeic acid in traditional Chinese medicines

Chlorogenic acid and caffeic acid often coexist in traditional Chinese medicines (TCMs) and play roles as antioxidation, antiviral, antitumor and anti-inflammatory agents. Due to their low content and the presence of structural analogues, they cannot be effectively separated by conventional extraction methods. Molecularly imprinted polymers, as synthesized receptors with antibody-like binding properties, have significant advantages in separating structural analogues. However, the harsh imprinting conditions easily induced the degradation of chlorogenic acid. Therefore, caffeic acid was used as an epitope template to replace chlorogenic acid for imprinting. Boronic acid-functionalized magnetic nanoparticles (MNPs) were selected as substrates, which could not only facilitate the immobilization and removal of the templates by pH regulation, but also achieve rapid separation under an external magnetic field. Tetraethyl orthosilicate was selected as an imprinting monomer which allowed for precise control of the thickness of the imprinting layer by adjusting the imprinting time. The prepared epitope-imprinted MNPs showed excellent specificity, in combination with high performance liquid chromatography, have been successfully applied to the selective separation and detection of chlorogenic acid and caffeic acid in TCMs.

Rapid identification of the geographical origin of Eucommia ulmoides by using excitation-emission matrix fluorescence combined with chemometric methods

Eucommia ulmoides is an important and valuable traditional Chinese medicine with various medical functions, and has been widely used as health food in China, Japan, South Korea and other Asian countries for many years. The efficacy and quality of E. ulmoides are closely associated with the geographical origin. In this work, the potential of excitation-emission matrix (EEMs) fluorescence coupled with chemometric methods was investigated for simple, rapid and accurate for identification E. ulmoides from different geographical origins. Parallel factor analysis (PARAFAC) was applied for characterizing the fluorescence fingerprints of E. ulmoides samples. Moreover, k-nearest neighbor (kNN), principal component analysis-linear discriminant analysis (PCA-LDA) and partial least squares discriminant analysis (PLS-DA) models were used for the classification of E. ulmoides samples according to their geographical origins. The results showed that kNN model was more suitable for identification of E. ulmoides samples from different provinces. The kNN model could identify E. ulmoides samples from eight different geographical origins with 100% accuracy on the training and test sets. Therefore, the proposed method was available for conveniently and accurately determining the geographical origin of E. ulmoides, which can expect to be an attractive alternative method for identifying the geographic origin of other traditional Chinese medicines.

Preparation of 5-hydroxymethylfurfural from Schisandra chinensis (Turcz.) Baill by high-speed counter-current chromatography: Comparison of conventional and consecutive separation

Schisandra chinensis is a kind of plant with high medicinal value, which contains many medicinal ingredients, including 5-hydroxymethylfurfural. In the present study, an efficient method based on high-speed counter-current chromatography was established for the preparation of 5-hydroxymethylfurfural from Schisandra chinensis. Petroleum ether-ethyl acetate-methanol-water (2:5:2:5, v/v) was selected as the solvent system for high-speed counter-current chromatography. In order to improve the yield of single separation, the sample size was continuously optimized and improved. The result showed that 1250 mg was the most suitable sample size, and 41 mg of the target compound with 97% purity was obtained by a single run. To further improve the yield, consecutive high-speed counter-current chromatography was introduced and compared with the results of high-speed counter-current chromatography single run. The results showed that although the purity was reduced to 92%, 430 mg of the target compound was obtained from 12.5 g of ethanol extract within 670 min after 10 consecutive injections. It indicated that consecutive separation not only increased the yield of the target compound, but also saved the separation time and greatly improved the separation efficiency of high-speed counter-current chromatography.

Chemical profiling, quantitation, and bioactivities of Du-Zhong tea

Du-Zhong tea is a health beverage produced from Eucommia ulmoides leaves (EUL) as raw materials using traditional tea processing and Chinese herbal pieces processing methods. To evaluate the differences between tender leaves and mature leaves of Du-Zhong tea, UPLC-Q-TOF MS was used to analyze the constituents in EUL collected in April and August. A total of 52 compounds, including iridoids, phenylpropanoids, flavonoids, lignans, and other types of compounds were identified. The contents of nine ingredients in the tender and mature leaves of E. ulmoides were determined by HPLC-DAD analysis. The results show that the average contents of the compounds in tender leaves were significantly higher than those in mature leaves. Lastly, the antioxidant and antipancreatic lipase activities of commercial Du-Zhong tea made by leaves of different maturity were evaluated. Du-Zhong tea with d-grade exhibited relatively higher antioxidant, while C-grade exhibited greater lipase inhibitory activities.

Protective effect of active components of Eucommia ulmoides leaves on gastric ulcers in rats: Involvement of the PI3K/Akt/NF-κB pathway

Eucommia ulmoides leaves are widely developed as food and medicines in China and Japan. Its main components have anti-inflammatory properties against gastric ulcers. The purpose of this study was to assess the protective role of an extract derived from the active components of Eucommia ulmoides leaves (EUL 50) against a gastric ulcer and analyze the underlying antiulcer mechanism. The main components of EUL 50 were identified using an ultra-performance liquid chromatography (UPLC) method. Network pharmacology and molecular docking were performed to predict the possible mechanism of action of EUL 50 in the treatment of gastric ulcers. The rats received EUL 50 intragastric administration twice a day for 3 days. Hydrochloric acid/ethanol (HCl/EtOH) was utilized to induce gastric ulcers, followed by histopathological and histochemical evaluation of the ulcer tissues and determination of the main oxidative stress parameters and inflammatory cytokines. The expression of PI3K/Akt/NF-κB pathway-related proteins was measured. Neochlorogenic acid, chlorogenic acid, rutin, and so on were identified as the major components of EUL 50 by UPLC. The prediction results identified the PI3K/Akt/NF-κB signaling pathway as the main possible protective mechanism against gastric ulcers. Furthermore, in a dose-dependent manner, EUL 50 reduced gastric tissue damage. In addition, the high dose of EUL 50 administration resulted in remarkable reductions in the levels of malondialdehyde (MDA), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin-1β (IL-1β) by 22.64%, 42.61%, 57.78%, and 56.51%, respectively, and suppression of the phosphorylation of Akt, p65, IKKα, and IκBα by 60.87%, 67.65, 74.58%, and 59.57%, respectively, and increased the antioxidant enzyme activity. EUL 50 is rich in flavonoids and organic acids that can act on the PI3K/Akt/NF-κB signaling pathway; as a result, oxidative stress and inflammation are considerably reduced, and gastric ulcers caused by HCl/EtOH are reduced. PRACTICAL APPLICATION: As a medicinal and food substance, Eucommia ulmoides leaves are widely used in the development of health products. EUL 50, a moderately polar part of E. ulmoides leaves, was obtained by extraction and enrichment and was found to have a better protective effect against HCl/EtOH-induced gastric ulcers. This finding can enrich the traditional application of E. ulmoides leaves and provide a basis for their health product development.

Bioactivity-Guided Separation of Anti-Cholinesterase Alkaloids from Uncaria rhynchophlly (Miq.) Miq. Ex Havil Based on HSCCC Coupled with Molecular Docking

As an important source of cholinesterase inhibitors, alkaloids in natural products have high potential value in terms of exerting pharmacological activities. In this study, a strategy for targeted preparation of cholinesterase inhibitors in Uncaria rhynchophlly (Miq.) Miq. ex Havil (UR) by high-speed counter-current chromatography was provided. In the method, a two-phase polar solvent system composed of ethyl acetate/n-butanol/water (1:4:5, v/v/v) was used, which isolated five alkaloids from the UR extract for the first time. All alkaloids were identified by HR-ESI-MS and NMR as 7-epi-javaniside (1), vincosamide (2), strictosamide (3), cadambine (4), and 3α-dihydrocadambine (5). The poorly resolved compounds 2 and 3 were separated by preparative HPLC (prep-HPLC). Among them, compounds 1, 4, and 5 were firstly obtained from UR. The purity of these plant isolates was 98.8%, 98.7%, 99.2%, 95.7%, and 98.5%, respectively. Compounds 1-5 exhibited an inhibitory effect on acetyl-cholinesterase and butyryl-cholinesterase with an IC50 from 1.47 to 23.24 µg/mL and 1.01 to 18.24 µg/mL. Molecular docking and inhibitory activities indicated that compound 1 showed stronger inhibitory activity on acetyl-cholinesterase and butyryl-cholinesterase.

Study on enhanced extraction and seasonal variation of secondary metabolites in Eucommia ulmoides leaves using deep eutectic solvents

It has been considered as a crucial field for the extraction of active ingredients from herbal medicine to use a green and efficient method in the medicinal and food industries. In recent years, deep eutectic solvents (DESs) have been obtaining increase attention in green chemistry area since its sustainability, safety and biodegradability. In this study, an efficient DES composed of choline chloride and L-(+)-ascorbic acid with a molar ratio of 2:1 performed higher efficacy on the extraction of target compounds (including iridoids, phenolic acids and flavonoids) in Eucommia ulmoides leaves than 50% methanol solution. Considering the extraction efficacy and time consumption, microwave-assisted extraction (MAE) was selected and the operational conditions, including power of microwave, liquid/solid ratio and irradiation time were optimized by response surface methodology (RSM). Water was used as anti-solvent to recover ten target analytes from DES with recovery yields of 97.59%, 94.91%, 96.09%, 90.66%, 95.16%, 87.33%, 86.57%, 82.15%, 89.28% and 80.75% for eucommiol (EU), aucubin (AU), geniposidic acid (GA), chlorogenic acid (CA), asperuloside (AP), rutin (RU), kaempferol-3-O-sambubioside (KS), isoquercitrin (IQ), kaempferol-3-O-rutinoside (KR) and astragaline (AS), respectively. By combining the DES-based MAE and quantitative analysis of multi-components by single mark (QAMS) methods, the contents of ten compounds in the leaves of Eucommia ulmoides were determined to clarify the relationship between the accumulation of secondary metabolites and the harvest period. It was found that the contents of main ingredients reached the highest during May to October. The period appears to be the best harvest period for Eucommia ulmoides leaves. This study provides a novel strategy for the harvesting, processing, and quality control of the raw materials from Eucommia ulmoides leaves.

Grey Relational Analysis Combined With Network Pharmacology to Identify Antioxidant Components and Uncover Its Mechanism From Moutan Cortex

The present study determines the potential antioxidants in Moutan Cortex (MC) and predicts its targets of anti-oxidative activities. The quantitative analysis and the free radical scavenging assays were conducted to detect the main components in MC and assess its anti-oxidant activities. The grey relational analysis and the network pharmacology approach were employed to predict its key components and targets of anti-oxidant activities. Six main constitutes in MCs were quantified by high performance liquid chromatography (HPLC) and its anti-oxidant activities were evaluated by DPPH and ABTS free radical scavenging methods. Then grey relational analysis was employed to predict the key components acting on anti-oxidative activity based on the chem-bio results. The predicted components and its mechanisms on anti-oxidation were uncovered by network pharmacology approach and cell test, respectively. The content of paeonol and paeoniflorin accounts for more than 80% the whole content of detected components. However, the two main ingredients showed a great variety among MCs. The antioxidant capacities of MCs also showed a great discrepancy based on DPPH and ABTS methods. The key components acting on anti-oxidation were identified to be paeonol, gallic acid and benzoylpaeoniflorin, and their potential therapeutic targets were predicted and verified, respectively. The present results reveal that MC has a significant antioxidant activity and the compounds of paeonol, gallic acid and benzoylpaeoniflorin could be considered as the promising antioxidant candidates with the property of suppressing oxidative stress and apoptosis.

Currently Applied Extraction Processes for Secondary Metabolites from Lippia turbinata and Turnera diffusa and Future Perspectives

The poleo (Lippia turbinata Griseb.) and damiana (Turnera diffusa Wild) are two of the most valued species in the Mexican semidesert due to their medicinal uses. The conventional essential oil extraction process is hydrodistillation, and for the extraction of antioxidants, the use of organic solvents. However, these techniques are time-consuming and degrade thermolabile molecules, and the efficiency of the process is dependent on the affinity of the solvent for bioactive compounds. Likewise, they generate solvent residues such as methanol, hexane, petroleum ether, toluene, chloroform, etc. Therefore, in recent years, ecofriendly alternatives such as ohmic heating, microwaves, ultrasound, and supercritical fluids have been studied. These methodologies allow reducing the environmental impact and processing times, in addition to increasing yields at a lower cost. Currently, there is no up-to-date information that provides a description of the ecofriendly trends for the recovery process of essential oils and antioxidants from Lippia turbinata and Turnera diffusa. This review includes relevant information on the most recent advancements in these processes, including conditions and methodological foundation.

Traditional application and modern pharmacological research of Eucommia ulmoides Oliv

As a Traditional Chinese Medicine, Eucommia ulmoides Oliv. has been used for the treatment of various diseases since ancient times, involving lumbar pain, knee pain, osteoporosis, hepatoprotection, paralysis, intestinal haemorrhoids, vaginal bleeding, abortion, spermatorrhoea, foot fungus, anti-aging etc. With the developing discovery of E. ulmoides extracts and its active components in various pharmacological activities, E. ulmoides has gained more and more attention. Up to now, E. ulmoides has been revealed to show remarkable therapeutic effects on hypertension, hyperglycemia, diabetes, obesity, osteoporosis, Parkinson's disease, Alzheimer's disease, sexual dysfunction. E. ulmoides has also been reported to possess antioxidant, anti-inflammatory, neuroprotective, anti-fatigue, anti-aging, anti-cancer and immunoregulation activities etc. Along these lines, this review summarizes the traditional application and modern pharmacological research of E. ulmoides, providing novel insights of E. ulmoides in the treatment of various diseases.

Valeriana rigida Ruiz & Pav. Root Extract: A New Source of Caffeoylquinic Acids with Antioxidant and Aldose Reductase Inhibitory Activities

Valeriana rigida Ruiz & Pav. (V. rigida) has long been used as a herbal medicine in Peru; however, its phytochemicals and pharmacology need to be scientifically explored. In this study, we combined the offline 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH)-/ultrafiltration-high-performance liquid chromatography (HPLC) and high-speed counter-current chromatography (HSCCC)/pH-zone-refining counter-current chromatography (pH-zone-refining CCC) to screen and separate the antioxidants and aldose reductase (AR) inhibitors from the 70% MeOH extract of V. rigida, which exhibited remarkable antioxidant and AR inhibitory activities. Seven compounds were initially screened as target compounds exhibiting dual antioxidant and AR inhibitory activities using DPPH-/ultrafiltration-HPLC, which guided the subsequent pH-zone-refining CCC and HSCCC separations of these target compounds, namely 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,4-O-di-caffeoylquinic acid, 3,5-O-di-caffeoylquinic acid, 4,5-O-di-caffeoylquinic acid, and 3,4,5-O-tri-caffeoylquinic acid. These compounds are identified for the first time in V. rigida and exhibited remarkable antioxidant and AR inhibitory activities. The results demonstrate that the method established in this study can be used to efficiently screen and separate the antioxidants and AR inhibitors from natural products and, particularly, the root extract of V. rigida is a new source of caffeoylquinic acids with antioxidant and AR inhibitory activities, and it can be used as a potential functional food ingredient for diabetes.

Skin-Related Properties and Constituents from the Aerial Parts Extract of Persicaria senticosa

In the course of screening for cosmetic ingredients by measuring antioxidant and antiwrinkle and whitening and anti-inflammatory activities, skin-related activity was tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, elastase inhibition, tyrosinase inhibition, and nitric oxide assay. Several Polygonaseae extracts were found to show potent activity. The results showed that the Persicaria senticosa methanolic extract has the 1,1­diphenyl-2­picrylhydrazyl (DPPH) and ABTS radical scavenging activities (IC₅₀ 61.0 and 17.5 μg/mL). In the elastase inhibition assay and nitric oxide assay, the IC₅₀ of methanolic extract of Persicaria senticosa was 739.7 μg/mL and 71.8 μg/mL. The Persicaria senticosa 70% ethanolic extract partitioned with n-hexane, CH₂Cl₂, EtOAc, n-BuOH, and aqueous fractions. The purification of EtOAc soluble layer was by column chromatography separation and MPLC analysis of Compounds 1-7. It was identified as loliolide (1), quercetin-3-O-glucoside (2), quercetin-3-O-glucuronide (3), 4-methoxy caftraric acid (4), kaempferol-3-(6-methylglucuronide) (5), quercetin-3-(6-methylglucuronide) (6), and quercetin (7). Structure was elucidated by a combination of 1D and 2D NMR and MS spectrometry as well as comparison with reported literatures. Radical scavenging effect on DPPH, tyrosinase inhibition, and nitric oxide assay on several compounds from Persicaria senticosa was found to show potent activity. The results showed that Compound 7 has the NO assay (IC₅₀29.7 μM). For DPPH, the IC₅₀ of Compounds 2, 3, 5, and 7 was 39.6, 31.2, 37.0, and 22.7 μM. In tyrosinase inhibitory activity, the IC₅₀ of Compound 7 was 14.3 μM.

Preparative separation of high-purity trans- and cis-ferulic acid from wheat bran by pH-zone-refining counter-current chromatography

Ferulic acid stereoisomers are the most abundant phenolic acids in cereal bran. However, it is challenging to separate them because of the similar structures and properties. In this study, a preparative separation method of ferulic acid stereoisomers from the crude extract of wheat bran was successfully developed. The method contained a two-step separation, the traditional counter-current chromatography (CCC, hexane: ethyl acetate: methanol: water = 2:5:2:4) was followed with a pH-zone-refining CCC (hexane: ethyl acetate: acetonitrile: water = 2:5:2:2, 10 mmol L^-1 trifluoroacetic acid in organic stationary phase and 10 mmol L^-1 ammonia in aqueous mobile phase). Trans-ferulic acid and cis-ferulic acid with HPLC high purity over than 99% and 98% can be yielded in large-scale separation. Moreover, it is found that different proton affinity, deprotonation ability and interaction site of hydrogen bond result in distinct partition behavior of stereoisomers, which is illustrated by quantitative analysis of molecular surface. This contributes to our in-depth understanding of the separation mechanism toward pH-zone refining CCC. The developed method can be applied in the exploitation of ferulic acids and related phenolic acids from other resources.

Stepwise elution by high-speed counter-current chromatography combined with a modified macroporous resin to isolate and purify antioxidant phenolics from discarded jackfruit (Artocarpusheterophyllus Lam.) peels

Combined with modified macroporous resin (MR), high-speed counter-current chromatography (HSCCC) was developed to separate and purify the antioxidant phenolics from waste jackfruit peels. First, the 4,4'-bis(chloromethyl)-1,1'-biphenyl was used to modify the commercially available adsorbent resin XAD-4 in order to enrich the antioxidant phenolics. Second, the resultant phenolics-rich fractions were further purified by HSCCC. In the separation process, the petroleum ether-ethyl acetate-methanol-0.1% acetic acid (5 : 5 : 3 : 7, v/v) upper phase was employed as an immobile phase. Afterwards, stepwise elution using petroleum the ether-ethyl acetate-methanol-0.1% acetic acid (5 : 5 : 3 : 7, v/v) lower phase was carried out during the initial 3.5 h, whereas the petroleum ether-ethyl acetate-methanol-0.1% acetic acid (5 : 5 : 6 : 4, v/v) lower phase was adopted for stepwise elution during the later 2.0 h. Four phenolics were obtained from 179 mg of the phenolics-rich fraction in a single run, including 41 mg chlorogenic, 27 mg gallic acid, 33 mg quercetin, and 29 mg catechin. 13C NMR, 1H NMR, and ESI-MS were employed to identify their structures.

The applicability of high-speed counter current chromatography to the separation of natural antioxidants

Antioxidants play an essential role in human health, as they have been found to be capable of lowering the incidence of many diseases, such as cancer and angiocardiopathy. Currently, more attention is paid to natural antioxidants because of the possible insecurity of synthetic antioxidants. Thus, the development of efficient techniques or methods to separate antioxidants from natural sources is requested urgently. High-speed counter current chromatography (HSCCC) is a unique support-free liquid-liquid chromatographic technique and has been widely applied in the field of separation of natural products. In this review, we summarize and analyze the related researches on the application of HSCCC in the separation of various natural antioxidants so far. The purpose of the article is to provide a certain theoretical support for the separation of natural antioxidants by HSCCC, and to make full use of advantages of HSCCC in the separation of bioactive components. In particular, some key problems associated with the separation strategies, the structural categories of natural antioxidants, solvent system choices, and the application of different elution modes in HSCCC separation, are summarized and commented. We expect that the content reviewed can offer more evidence for the development of the field of natural antioxidants separation, so as to achieve large-scale preparation of natural antioxidants.

Comparison of the Antioxidant Activities and Phenolic Content of Five Lonicera Flowers by HPLC-DAD/MS-DPPH and Chemometrics

The Lonicera plants (family Caprifoliaceae) with strong antioxidant activity are used as potential health-supporting phytochemicals. Studying the detailed relationships between bioactive compounds and their antioxidant activity is important for further comprehensive development and application of them. In this paper, the antioxidant capacities and compositions of five species of Lonicera flowers were investigated by using the online HPLC-DAD/MS-DPPH method. Results indicated that the samples contained higher amounts of phenols had better antioxidant activity. Furthermore, principal component analysis and linear regression were further used to analyze the correlations between antioxidant capacity and compounds and find the compounds having higher contribution to antioxidant activity. 5-O-Caffeoylquinic acid, 4-O-caffeoylshikimic acid, methyl-5-O-caffeoylquinate, 1,4-di-O-caffeoylquinic acid, and 3,4,5-tri-O-caffeoylquinic acid were screened as stronger antioxidant candidates. In this study, HPLC-DAD/MS and antioxidant activity methods were combined together to analyze the compounds' information and activity assays of Lonicera, which might provide more evidence for its quality control.

Research Progress in Liver-Regenerating Microenvironment and DNA Methylation in Hepatocellular Carcinoma: The Role of Traditional Chinese Medicine

The development, progression, recurrence, and metastasis of hepatocellular carcinoma (HCC) are closely associated with an abnormal liver-regenerating microenvironment (LRM). Therefore, preventing and reversing an abnormal LRM is a potential therapeutic strategy against HCC. Studies are increasingly focusing on the impact of regeneration, fibrosis, angiogenesis, inflammation, immunomodulation, and hepatic stem cells on HCC development and progression. As a key epigenetic mechanism, DNA methylation is extensively involved in regulating physiological and pathological pathways. In this review, we summarize recent findings on the role of DNA methylation in the fibrotic, angiogenic, inflammatory/immune, and stem cell microenvironments of HCC, and discuss new advances in Traditional Chinese Medicine (TCM) on influencing the abnormal LRM, so as to gain new insights into alleviating the abnormal LRM via regulating DNA methylation by TCM.

Isolation and purification of four phenolic glycoside isomers from the leaves of Idesia polycarpa Maxim. by high-speed counter-current chromatography and preparative high-performance liquid chromatography

We established an efficient method using high-speed counter-current chromatography (HSCCC) combined with preparative high-performance liquid chromatography (prep-HPLC) for isolating and purifying phenolic glycoside isomers. The method involves a rapid and sensitive ultra-performance liquid chromatography-under voltage(UPLC-UV) technique using a sub-2 μm core-shell particle column for qualitative and quantitative analysis of four phenolic glycoside isomers from Idesia polycarpa Maxim. leaves. The partially purified samples from ethyl acetate extraction of ethanol extracts of I. polycarpa Maxim. leaves were obtained by HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water solution (3:5:3:5, v/v/v/v) to obtain fractions I and II, which contain two phenolic glycoside isomers. The two fractions were further isolated by prep-HPLC to yield compounds 1, 2, 3, and 4 with purities of 98.29%, 98.71%, 98.49% and 98.52%, and total recoveries of 93.5%, 72.2%, 75.5% and 88.3%, respectively. Compound 1 was first isolated from I. polycarpa Maxim., while compound 2 was reported to be a new phenolic glycoside, which is 1-[(6'-O-(Z)-p-coumaroyl)-β-D-glucopyranosyl]-oxy-2-phenol. The chemical structures of the four phenolic glycoside isomers were analyzed and confirmed by UPLC, UV, electrospray ionization mass spectrometry (ESI-MS), fourier transform infra-red (FT-IR), 1H-nuclear magnetic resonance (1H NMR), 13C-nuclear magnetic resonance (13C NMR) and 2D nuclear magnetic resonance (2D NMR) spectra. This study opens prospects for broad industrial applications of HSCCC/prep-HPLC for the isolation and purification of isomers.

Geographic Authentication of Eucommia ulmoides Leaves Using Multivariate Analysis and Preliminary Study on the Compositional Response to Environment

To explore the influences of different cultivated areas on the chemical profiles of Eucommia ulmoides leaves (EUL) and rapidly authenticate its geographical origins, 187 samples from 13 provinces in China were systematically investigated using three data fusion strategies (low, mid, and high level) combined with two discrimination model algorithms (partial least squares discrimination analysis; random forest, RF). RF models constructed by high-level data fusion with different modes of different spectral data (Fourier transform near-infrared spectrum and attenuated total reflection Fourier transform mid-infrared spectrum) were most suitable for identifying EULs from different geographical origins. The accuracy rates of calibration and validation set were 92.86% and 93.44%, respectively. In addition, climate parameters were systematically investigated the cluster difference in our study. Some interesting and novel information could be found from the clustering tree diagram of hierarchical cluster analysis. The Xinjiang Autonomous Region (Region 5) located in the high latitude area was the only region in the middle temperate zone of all sample collection areas in which the samples belonged to an individual class no matter their distance in the tree diagram. The samples were from a relatively high elevation in the Shennongjia Forest District in Hubei Province (>1200 m), which is the main difference from the samples from Xiangyang City (78 m). Thus, the sample clusters from region 9 are different from the sample clusters from other regions. The results would provide a reference for further research to those samples from the special cluster.

Biosurfactant trehalose lipid-enhanced ultrasound-assisted micellar extraction and determination of the main antioxidant compounds from functional plant tea

Hydrosoluble trehalose lipid (a biosurfactant) was employed for the first time as a green extraction solution to extract the main antioxidant compounds (geniposidic acid, chlorogenic acid, caffeic acid, and rutin) from functional plant tea (Eucommia ulmoides leaves). Single-factor tests and response surface methodology were employed to optimize the extraction conditions for ultrasound-assisted micellar extraction combined with ultra-high-performance liquid chromatography in succession. A Box-Behnken design (three-level, three-factorial) was used to determine the effects of extraction solvent concentration (1-5 mg/mL), extraction solvent volume (5-15 mL), and extraction time (20-40 min) at a uniform ultrasonic power and temperature. In consequence, the best analyte extraction yields could be attained when the trehalose lipid solution concentration was prepared at 3 mg/mL, the trehalose lipid solution volume was 10 mL and the extraction time was set to 35 min. In addition, the recoveries of the antioxidants from Eucommia ulmoides leaves analyzed by this analytical method ranged from 98.2 to 102%. These results indicated that biosurfactant-enhanced ultrasound-assisted micellar extraction coupled with a simple ultra-high-performance liquid chromatography method could be effectively applied in the extraction and analysis of antioxidants from Eucommia ulmoides leaf samples.

Antiosteoporotic activities of isoquercitrin in ovariectomized rats: Role of inhibiting hypoxia inducible factor-1 alpha

Postmenopausal osteoporosis is a common and disabling disorder that increases the risk of bone fractures due to estrogen deprivation; this can be simulated in rats by ovariectomy. Hypoxia inducible factor-1 alpha (HIF-1α) expression in osteoclasts predominantly leads to its activation increasing bone resorption. Premenopausal, estrogen prevents HIF-1α expression maintaining bone density. Unfortunately postmenopausal estrogen replacement therapy is not recommended due to its potential tumor development risk. Isoquercitrin, a common edible plants phytoestrogen, is known to inhibit HIF-1α. This study was conducted to investigate the potential antiosteoporotic activity of isoquercitrin (15, 30 and 60 mg/kg/day) in ovariectomized rats with reference to 17β-estradiol (25 mcg/kg/day). Animals were bilaterally ovariectomized to induce osteoporosis and one month later they were assigned into groups and administered isoquercitrin and 17β-estradiol for 8 weeks. Ovariectomy reduced lumbar compression strength, distorted bone microscopic architecture, inducing cartilage and trabecular dystrophy, and increased the markers of bone turnover (serum alkaline phosphatase and osteocalcin and urinary calcium, phosphorus and creatinine). It also increased the gene expression of HIF-1α and the levels of nuclear factor-kappa B (NF-κB) and decreased the expression of vascular endothelial growth factor (VEGF) and β-catenin in the femurs. Isoquercitrin was found to improve bone histological features, increase lumbar strength and improve most of the biochemical markers of bone turnover in a manner comparable to 17β-estradiol. Isoquercitrin also attenuated the increased HIF-1α expression while increased that of the VEGF and β-catenin. It also decreased the levels of NF-κB. Therefore isoquercitrin may be considered a safer alternative for managing osteoporosis.

Dietary supplementation with the extract from Eucommia ulmoides leaves changed epithelial restitution and gut microbial community and composition of weanling piglets

This study was conducted to compare the effects of Eucommia ulmoides leaves (EL) in different forms (EL extract, fermented EL, and EL powder) with antibiotics on growth performance, intestinal morphology, and the microbiota composition and diversity of weanling piglets. Compared to the control group, the antibiotics and EL extract significantly increased the average daily gain and decreased the feed: gain ratio as well as the diarrhea rate (P < 0.05). The EL extract significantly decreased the crypt depth and increased the ratio of villus height to crypt depth (P < 0.05), while the fermented EL group did the opposite (P < 0.05). The crypt depth in the antibiotics group was of similar value to the EL extract group, and was lower than the fermented EL and EL powder groups (P < 0.05). Compared to the control and antibiotics groups, the jejunul claudin-3 mRNA expression and the concentrations of total VFA, Chao 1, and ACE were significantly augmented in the EL extract group of piglets (P < 0.05). The EL extract groups also showed elevated Shannon (P < 0.05) and Simpson (P = 0.07) values relative to the control and antibiotics groups. At the phylum level, the EL extract group exhibited a reduced abundance of Bacteroidetes and an enhanced abundance of Firmicutes. At the genus level, the abundance of Prevotella was augmented in the EL extract group. Moreover, compared with the antibiotic group, the acetate concentration was enhanced in the EL extract and fermented EL groups. Overall, dietary supplementation with the EL extract, but not the fermented EL or EL powder, improved growth performance, jejunul morphology and function, as well as changed colonic microbial composition and diversity, which might be an alternative to confer protection against weanling stress in weanling piglets.

Potential of isoquercitrin as antisickling agent: a multi-spectroscopic, thermophoresis and molecular modeling approach

Sickle cell disease is an inherited disease caused by point mutation in hemoglobin (β-globin gene). Under oxygen saturation, sickle hemoglobin form polymers, leading to rigid erythrocytes. The transition of the blood vessels is altered and initiated by the adhesion of erythrocytes, neutrophils and endothelial cells. Sickle Hemoglobin (HbS) polymerization is a major cause in red blood cells (RBC), promoting sickling and destruction of RBCs. Isoquercitrin, a medicinal bioactive compound found in various medicinal plants, has multiple health benefits. The present study examines the potential of isoquercitrin as an anti-sickle agent, showing a significant decrease in the rate of polymerization as well as sickling of RBCs. Isoquercitrin-induced graded alteration in absorbance and fluorescence of HbS, confirmed their interaction. A negative value of ΔG° strongly suggests that it is a spontaneous exothermic reaction induced by entropy. Negative ΔH° and positive ΔS° predicted that hydrogen and hydrophobic binding forces interfered with a hydrophobic microenvironment of β6Val leading to polymerization inhibition of HbS. HbS-Isoquercitrin complex exhibits helical structural changes leading to destabilization of the HbS polymer as confirmed by CD spectroscopy. MST and DSC results indicate greater changes in thermophoretic mobility and thermal stability of sickle hemoglobin in the presence of isoquercitrin, respectively. These findings were also supported by molecular simulation studies using DOCK6 and GROMACS. Hence, we can conclude that isoquercitrin interacts with HbS through hydrogen bonding, which leads to polymerization inhibition. Consequently, isoquercitrin could potentially be used as a medication for the treatment of sickle cell disease.Communicated by Ramaswamy H. Sarma.

Identification and quantitative analysis of phenolic glycosides with antioxidant activity in methanolic extract of Dendrobium catenatum flowers and selection of quality control herb-markers

Recently, the flowers of Dendrobium catenatum (D. officinale) have been approved as new food ingredient. This study aimed to investigate the herb-markers and their antioxidant activities in methanolic extracts of D. catenatum flowers, and to establish the quality evaluation methods for raw materials and their products of flower by HPLC. The methanolic extract of 11 strains of D. catenatum flowers were found to contain a high content of total phenol and flavonoids, and they possessed potential antioxidant capacities based on DPPH radical scavenging assay. A total of 21 phenolic herb-markers were selected according to the similarity and principal component analysis of the chromatographic fingerprinting profiles. Their structures were further elucidated by UV, HPLC-DAD-ESI-QTOF-MS/MS and NMR analyses. The identified compounds included 2 phenylpropanoids, 11C-glycosylflavones and 6 O-glycosylflavones, which could be employed as the indicators for quantitative evaluation of the quality and authenticity of the flowers. Based on the pre-column DPPH/ABTS⁺-HPLC analysis, the major compounds contributed to the antioxidative activity were identified as 1-O-caffeoyl-β-D-glucoside, rutin and isoquercitrin, all of which, were also the most abundant constituents in the methanolic extract. The results suggest the potential of D. catenatum flowers as a new antioxidant resources for medicinal and food products.

Aldose Reductase, Protein Glycation Inhibitory and Antioxidant of Peruvian Medicinal Plants: the Case of Tanacetum parthenium L. and Its Constituents

Diabetes complications, including peripheral neuropathy, cataracts, impaired wound healing, vascular damage, arterial wall stiffening and retinopathy diseases, are among the most predominant health problems facing the world's population today. The 22 Peruvian plant extracts were screened for their potential inhibitory activity against rat lens aldose reductase (RLAR) and DPPH radical scavenging. Among them, we have found that Tanacetum parthenium L. (TP) has the RLAR, AGEs and DPPH radical scavenging activities. We used for screening of active components in TP against RLAR and DPPH for the first time by ultrafiltration (UF) and DPPH. Compounds in TP were isolated by Sephadex column chromatography and their structures were established by MS and NMR spectroscopic analyses. Among the isolated compounds, ferulic acid, apigenin, luteolin-7-O-glucoside, luteolin, chrysosplenol, and kaempferol showed potent inhibition with IC50 values of 1.11-3.20 and 6.44-16.23 μM for RLAR and DPPH radical scavenging. Furthermore, these compounds suppressed sorbitol accumulation in rat lenses and ferulic acid, luteolin-7-O-glucoside, and luteolin have AGEs inhibitory activities with IC50 values of 3.43-6.73 μM. In summary, our study provides interesting plants for further study with respect to the treatment and prevention of diabetic complication of Peruvian plant and can provide the scientific base of the traditional uses.

Comparative analysis of sixteen active compounds and antioxidant and anti-influenza properties of Gardenia jasminoides fruits at different times and application to the determination of the appropriate harvest period with hierarchical cluster analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Gardenia jasminoides fruit (GJF) is used as a well-known traditional folk medicine, a food and a natural colorant in Asia with a long history. The herbal medicine has usually been harvested in the autumn from September to November. However, this time span is too long and might result in the quality instability of GJF.

AIM OF STUDY

We aimed to conduct the comprehensive quality evaluation of GJF including the quantitative analysis of the bioactive components and the main bioactivities, and further to determine the most appropriate harvest time of this phytomedicine.

MATERIALS AND METHODS

In this study, an UFLC-Q-TRAP-MS/MS method was established to quantify 7 iridoid glycosides (geniposide, geniposidic acid, secoxyloganin, gardenoside, genipin 1-gentiobioside, scandoside methyl ester, and shanzhiside), 7 phenylpropanoid acids (chlorogenic acid, cryptochlorogenic acid, neochlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C, and caffeic acid) and 2 carotenoids (crocin-1 and crocin-2) in GJF. With this method, nine samples of GJF harvested at different times were analyzed and compared. These samples were also investigated and compared in terms of their antioxidant activity (DPPH free radical scavenging, ABTS free radical scavenging, ferric-reducing antioxidation) and anti-influenza activity (neuraminidase inhibition), which are closely related to the GJF efficacies. Then, hierarchical cluster analysis (HCA) was separately performed for the quantitative analysis and bioactivity evaluation in vitro.

RESULTS

The HCA results demonstrated that three GJF samples (S5, S6, and S7) were clustered into one group for both quantitative analysis and bioactivity evaluation in vitro; these three samples were found to have the highest standardized scores in both the former (12.775, 12.106, 10.817) and the latter (3.406, 3.374, 3.440). Based on the comprehensive results, the optimum harvest period was confirmed to extend from mid-October to early-November.

CONCLUSIONS

This study firstly validated the use of UFLC-Q-TRAP-MS/MS method for the determination of 16 bioactive components in GJF. It was also the first time that a quantitative analysis and a bioactivity assay in vitro were integrated for the determination of the most appropriate harvest period of GJF. We hope this paper may provide some reference to studies of appropriate harvest periods and even the quality control of TCMs.