Metabolic profiling of antioxidants constituents in Artemisia selengensis leaves

Analysis of Antioxidant Compounds in Vitex negundo Leaves Using Offline 2D-LC-ECD and LC-MS/MS

Vitex negundo has strong antioxidant activity, but its primary antioxidant components are not clear. In this study, the antioxidant components were screened by offline two-dimensional liquid chromatography coupled with electrochemical detection (2D-LC-ECD) and subsequently assessed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification, radical scavenging capacity, and molecular docking. Various fractions were isolated from Vitex negundo leaves, and 39 antioxidant components were screened and identified. All of the fractions containing the antioxidant components exhibited certain antioxidant activity. Correlation analysis revealed a strong correlation between the response of LC-ECD and the in vitro antioxidant activity of the fractions. Molecular docking demonstrated that components with high response to LC-ECD exhibited robust interaction with antioxidant-related target proteins. The main antioxidant components of Vitex negundo leaves were isoorientin, chlorogenic acid, agnuside, cynaroside, and scutellarin. The 2D-LC-ECD combined with LC-MS/MS was rapid and effective in screening the antioxidant components in Vitex negundo leaves and could also provide technical support for the discovery of antioxidant components with different polarities and contents in other medicinal and edible plants.

Rapid screening and evaluation of natural antioxidants from leaf, stem, and root of Artemisia argyi by online liquid microextraction combined with HPLC-based antioxidant assay system coupled with calibration quantitative analysis

To reveal the utilization value of leaf, stem, and root of Artemisia argyi, a rapid online liquid microextraction combined with a high-performance liquid chromatography coupled with 2,2-nitrogen-di (3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt antioxidant assay system was established for analysis of antioxidants in the leaf, stem, and root of A. argyi, and a calibration quantitative method of antioxidant activity with equivalent chlorogenic acid was proposed. Thirty-three positive peaks were identified; among them, 12 compounds were found that possess good antioxidant activity including eleven organic acids (components 2-4, 8, 11-14, 17, 19, and 21) and one flavonoids (component 22). The proposed calibration quantitative method avoided the influence of content of compound and compared the extent of radical scavenging capacity of five antioxidant compounds, which were ranked as follow: 3,5-dicaffeoylquinic acid > 3,4-dicaffeoylquinic acid ≈ 4,5-dicaffeoylquinic acid > 1,4-dicaffeoylquinic acid > chlorogenic acid. In conclusion, this study provided composition and biological potential for the future development of the leaf, stem, and root of A. argyi. It is believed that the online liquid microextraction combined with high-performance liquid chromatography based antioxidant assay system can be widely used for the rapid screening of natural antioxidant components in the different parts of natural products.

Chemical Composition of Thyme (Thymus vulgaris) Extracts, Potential Inhibition of SARS-CoV-2 Spike Protein-ACE2 Binding and ACE2 Activity, and Radical Scavenging Capacity

Water and ethanol extracts of dried thyme (Thymus vulgaris) were analyzed for chemical composition, inhibition of the SARS-CoV-2 spike protein-ACE2 interaction, inhibition of ACE2 activity, and free radical scavenging capacity. Thirty-two compounds were identified in water extract (WE) and 27 were identified in ethanol extract (EE) of thyme through HPLC-MS. The WE (33.3 mg/mL) and EE (3.3 mg/mL) of thyme inhibited the spike protein-ACE2 interaction by 82.6 and 86.4%, respectively. The thyme WE at 5 mg/mL inhibited ACE2 activity by 99%, and the EE at 5 mg/mL inhibited ACE2 by 65.8%. Total phenolics were determined to be 38.9 and 8.8 mg of GAE/g in WE and EE, respectively. The HO• scavenging capacities were 1121.1 and 284.4 μmol of TE/g in WE and EE, respectively. The relative DPPH• scavenging capacities were 126.3 μmol TE/g in WE and 28.2 μmol TE/g in EE. The ABTS•+ scavenging capacities were 267.1 μmol TE/g in WE and 96.7 μmol TE/g in EE. The results suggested that the thyme extract could be potentially used to prevent SARS-CoV-2 infection and mitigate the complications from the infection.

Metabolomic analysis and antibacterial and antioxidant activities of three species of Artemisia plants in Tibet

BACKGROUND

Artemisia is important medicinal plants in China and are widely used in medicine, agriculture, and food. Pharmacologically active components of the plants remain to be investigated.

METHODS

This study sought to identify and compare the chemical constituents of three species of Artemisia in Tibet using a widely-targeted metabolomics approach and their antibacterial and antioxidant capacities were determined.

RESULT

A total of 1109 metabolites within 10 categories were detected from the three species of Artemisia, including lipids, amino acids, nucleotides, flavonoids, terpenes, coumarins, organic acids, and phenolic acids. 732 different metabolites have been identified between Artemisia sieversiana and Artemisia annua, 751 different metabolites were identified between Artemisia wellbyi and A. sieversiana, and 768 differential metabolites were differentially detected from A. wellbyi and A. annua. Differentially identified compounds included flavonoids, phenolic acids, artemisinins and coumarin. A. annua contained the highest relative content of artemisinin among three Artemisia. The antimicrobial experiments showed that the three Artemisia species had strong antibiotic activities against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Proteus mirabilis and Pseudomonas aeruginosa. The biochemical analysis showed that the three species of Artemisia have strong antioxidant capacity.

CONCLUSIONS

This is the first reported attempt to comparatively determine the types of the metabolites of the three widely distributed Artemisia species in Tibet. The information should help medicinal research and facilitate comprehensive development and utilization of Artemisia species in Tibet.

Transcriptome and Metabolome Analysis Reveal the Flavonoid Biosynthesis Mechanism of Abelmoschus manihot L. at Different Anthesis Stages

Abelmoschus manihot L. (HSK) is a rare and endangered species in the wild that grows on the cliffs of deep mountains. As a natural plant, the chemical composition of HSK is relatively complex, which mainly includes flavonoids, organic acids, polysaccharides, and various trace elements with good effects of clearing away heat, anti-inflammatory, analgesic, and calming nerves, and inhibiting tumor cells. In this experiment, different developmental stages of HSK flowers were used for optimization of the flavonoid extraction and determining method. The antioxidant activities, flavonoid accumulation pattern, and synthesis regulatory network were analyzed using biochemistry, RNA-seq, and UPLC-MS/MS. The total content of flavonoids, vitexin rhamnoside, hyperoside, and rutin in HSK flowers at T3 stage (flower wilting) was significantly higher than in T2 (full flowering) and T1 (bud) stages. Compared with T1 and T2, the antioxidant capacity of the T3 flower alcohol extract was also the strongest, including the total reducing ability, DPPH clearance, OH clearance, O^2- clearance, and total antioxidant capacity. A total of 156 flavonoids and 47,179 unigenes were detected by UPLC-MS/MS and RNA-Seq, respectively. The candidate genes and key metabolites involved in flavonoid biosynthesis were identified and the regulatory networks were also analyzed in this study. qRT-PCR test further proved that the gene expression level was consistent with the results of RNA sequence data. The relationship between the gene expression and flavonoid accumulation network provides a theoretical basis for the mining and regulation of functional genes related to the flavonoid biosynthesis and metabolism in Abelmoschus manihot L.

Chemical Compositions of Clove (Syzygium aromaticum (L.) Merr. & L.) Extracts and Their Potentials in Suppressing SARS-CoV-2 Spike Protein-ACE2 Binding, Inhibiting ACE2, and Scavenging Free Radicals

COVID-19 is initiated by binding the SARS-CoV-2 spike protein to angiotensin-converting enzyme 2 (ACE2) on host cells. Food factors capable of suppressing the binding between the SARS-CoV-2 spike protein and ACE2 or reducing the ACE2 availability through ACE2 inhibitions may potentially reduce the risk of SARS-CoV-2 infection and COVID-19. In this study, the chemical compositions of clove water and ethanol extracts were investigated, along with their potentials in suppressing SARS-CoV-2 spike protein-ACE2 binding, reducing ACE2 availability, and scavenging free radicals. Thirty-four compounds were tentatively identified in the clove water and ethanol extracts, with six reported in clove for the first time. Clove water and ethanol extracts dose-dependently suppressed SARS-CoV-2 spike protein binding to ACE2 and inhibited ACE2 activity. The water extract had stronger inhibitory effects than the ethanol extract on a dry weight basis. The clove water extract also had more potent free radical scavenging activities against DPPH^• and ABTS^•+ (536.9 and 3525.06 μmol TE/g, respectively) than the ethanol extract (58.44 and 2298.01 μmol TE/g, respectively). In contrast, the ethanol extract had greater total phenolic content (TPC) and relative HO^• scavenging capacity (HOSC) values (180.03 mg GAE/g and 2181.08 μmol TE/g, respectively) than the water extract (120.12 mg GAE/g and 1483.02 μmol TE/g, respectively). The present study demonstrated the potential of clove in reducing the risk of SARS-CoV-2 infection and COVID-19 development.

Fructus Zanthoxyli extract improves glycolipid metabolism disorder of type 2 diabetes mellitus via activation of AMPK/PI3K/Akt pathway: Network pharmacology and experimental validation

OBJECTIVE

This study investigated the potential mechanisms behind the beneficial effects of Fructus Zanthoxyli (FZ) against type 2 diabetes mellitus (T2DM) based on network pharmacology and experimental validation.

METHODS

Ultra-high-performance liquid chromatography coupled with hybrid quadrupole-orbitrap high-resolution mass spectrometry, and gas chromatography-mass spectrometry were used to identify the constituents of FZ. Next, the differentially expressed genes linked to the treatment of diabetes with FZ were screened using online databases (including Gene Expression Omnibus database and Swiss Target Prediction online database), and the overlapping genes and their enrichment were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, the pathway was verified by in vitro experiments, and cell staining with oil red and Nile red showed that the extract of FZ had a therapeutic effect on T2DM.

RESULTS

A total of 43 components were identified from FZ, and 39 differentially expressed overlapping genes were screened as the possible targets of FZ in T2DM. The dug component-target network indicated that PPARA, PPARG, PIK3R3, JAK2 and GPR88 might be the core genes targeted by FZ in the treatment of T2DM. Interestingly, the enrichment analysis of KEGG showed that effects of FZ against T2DM were closely correlated with the adenosine monophosphate-activated protein kinase (AMPK) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathways. In vitro experiments further confirmed that FZ significantly inhibited palmitic acid-induced lipid formation in HepG2 cells. Moreover, FZ treatment was able to promote the AMPK and PI3K/Akt expressions in HepG2 cells.

CONCLUSION

Network pharmacology combined with experimental validation revealed that FZ extract can improve the glycolipid metabolism disorder of T2DM via activation of the AMPK/PI3K/Akt pathway.

A preliminary study of the chemical composition and bioactivity of Bombax ceiba L. flower and its potential mechanism in treating type 2 diabetes mellitus using ultra-performance liquid chromatography quadrupole-time-flight mass spectrometry and network pharmacology analysis

This study aimed to preliminary investigate the phytochemistry, bioactivity, hypoglycemic potential, and mechanism of action of Bombax ceiba L. flower (BCF), a wild edible and food plant in China. By using methanol extraction and liquid-liquid extraction, the crude extract (CE) of BCF and its petroleum ether (PE), dichloromethane (DCM), ethyl acetate (EtOAc), n-butanol (n-BuOH), and aqueous (AQ) fractions were obtained, and their chemical components and biological activities were evaluated. Further high-performance liquid chromatography (HPLC) analysis was carried out to identify and quantify the active constituents of BFC and its five fractions, and the phytochemical composition of the best-performing fraction was then analyzed by ultra-performance liquid chromatography quadrupole-time-flight mass spectrometry (UPLC/Q-TOF-MS). Finally, a network pharmacology strategy based on the chemical profile of this fraction was applied to speculate its main hypoglycemic mechanism. Results revealed the excellent biological activities of BCF, especially the EtOAc fraction. In addition to the highest total flavonoid content (TFC) (367.72 μg RE/mg E) and total phenolics content (TPC) (47.97 μg GAE/mg E), EtOAc showed the strongest DPPH⋅ scavenging ability (IC₅₀ value = 29.56 μg/mL), ABTS⋅⁺ scavenging ability (IC₅₀ value = 84.60 μg/mL), and ferric reducing antioxidant power (FRAP) (889.62 μg FeSO₄/mg E), which were stronger than the positive control BHT. EtOAc also exhibited the second-best α-glucosidase inhibitory capacity and second-best acetylcholinesterase (AChE) inhibitory capacity with the IC₅₀ values of 2.85 and 3.27 mg/mL, respectively. Also, EtOAc inhibited HepG2, MCF-7, Raw264.7, and A549 cell with IC₅₀ values of 1.08, 1.62, 0.77, and 0.87 mg/mL, which were the second or third strongest in all fractions. Additionally, HPLC analysis revealed significant differences in the compounds’ abundance between different fractions. Among them, EtOAc had the most detected compounds and the highest content. According to the results of UPLC/Q-TOF-MS, 38 compounds were identified in EtOAc, including 24 phenolic acids and 6 flavonoids. Network pharmacological analysis further confirmed 41 potential targets of EtOAc in the treatment of type 2 diabetes, and intracellular receptor signaling pathways, unsaturated fatty acid, and DNA transcription pathways were the most possible mechanisms. These findings suggested that BCF was worthwhile to be developed as an antioxidant and anti-diabetic food/drug.

Phenolic fingerprints of the Pacific seagrass Phyllospadixtorreyi - Structural characterization and quantification of undescribed flavonoid sulfates

Four undescribed flavonoid sulfates were isolated from Phyllospadix torreyi S. Watson foliar tissue. In addition, nine known flavonoid sulfates and three phenolic acids were isolated from the same extract, of which seven had never been reported for the genus Phyllospadix. Structural elucidation of individual phenolics was assigned using complementary informations from their spectral evidence (HPLC-DAD, LC-MS, NMR, and UV) and chemical behavior. The inter-annual variation in phenolic concentrations was determined by quantitative HPLC-DAD over a three-year period. The results showed a relative constancy of phenolic content over time and the high prevalence of flavonoid disulfates (70-90% of the total flavonoids detected). All samples were found dominated by the unreported nepetin 7, 3'-disulfate and 5-methoxyluteolin 7, 3'-disulfate, followed by luteolin 7, 3'-disulfate. Considering the economic potential of flavonoid sulfates in the pharmaceutical and nutraceutical segments, a sample of detrital leaves was also analyzed. The same phenolic pattern was found and the concentration of the individuals, although lower than in fresh material, makes this abundant biomass of interest for dietary and pharmaceutical applications.

Artemisia selengensis Turcz. leaf extract promotes longevity and stress resistance in Caenorhabditis elegans

BACKGROUND

Artemisia selengensis Turcz. (AST) is a common edible and medicinal herb possessing extensive biological activities and various health-promoting functions. However, the anti-aging effects of AST have been neglected. This work evaluated the effects of AST leaf extract (ASTE) on stress tolerance and longevity in Caenorhabditis elegans.

RESULTS

ASTE treatment enhanced stress resistance and significantly extended the lifespan of C. elegans. Moreover, ASTE prolonged the healthspan by increasing body bending and pharyngeal pumping rates, and by reducing the intestinal lipofuscin level and accumulation of intracellular reactive oxygen species (ROS). Caffeoylquinic acids in ASTE, especially dicaffeoylquinic acids, were the major components responsible for these benefits. The mechanism underlying the anti-aging effect of ASTE occurred by activating insulin/insulin-like growth factor, SIR-2.1 signaling and mitochondrial dysfunction pathways, which in turn induced the activity of the transcription factors DAF-16/FOXO and SKN-1/Nrf2.

CONCLUSION

These findings provide direct evidence for the anti-aging effects of AST and reveal its potential on promoting healthy aging. © 2022 Society of Chemical Industry.

Morphological and physiological changes in Artemisia selengensis under drought and after rehydration recovery

Changes in global climate and precipitation patterns have exacerbated the existing uneven distribution of water, causing many plants to face the alternate situation of drought and water flooding. We studied the growth and physiological response of the wetland plant Artemisia selengensis to drought and rehydration. In this study, Artemisia selengensis seedlings were subjected to 32.89% (SD), 47.36 % (MD), 60.97% (MID), and 87.18 % (CK) field water holding capacity for 70 days, followed by 14 days of rehydration. The results showed that drought inhibited the increase of plant height, basal diameter, and biomass accumulation under SD and MD, but the root shoot ratio (R/S) increased. Drought stress also decreased the content of total chlorophyll (Chl), chlorophyll a (Chl-a), chlorophyll b (Chl-b), and carotenoid (Car). Soluble sugar (SS) and proline (Pro) were accumulated rapidly under drought, and the relative water content (RWC) of leaves was kept at a high level of 80%. After rehydration, the plant height, basal diameter, biomass, and R/S ratio could not be recovered under SD and MD, but these indicators were completely recovered under MID. The RWC, Chl, Chl-a, Chl-b, Car, and osmotic substances were partially or completely recovered. In conclusion, Artemisia selengensis not only can improve drought resistance by increasing the R/S ratio and osmotic substances but also adopt the compensatory mechanism during rehydration. It is predictable that A. selengensis may benefit from possible future aridification of wetlands and expand population distribution.

Protective effects of di-caffeoylquinic acids from Artemisia selengensis Turcz leaves against monosodium urate-induced inflammation via the modulation of NLRP3 inflammasome and Nrf2 signaling pathway in THP-1 macrophages

Artemisia selengensis Turcz (AST) as a common vegetable is rich in di-caffeoylquinic acids (di-CQAs) and has been reported to possess multiple health benefits. However, whether di-CQAs from AST leaf extracts (ASTE) could alleviate gout inflammation is still unknown. Herein, this study explored the inhibitory mechanism of ASTE on gout inflammation in THP-1 macrophages. Results suggested that ASTE suppressed the secretion and mRNA levels of inflammatory cytokines including interleukin-18, interleukin-1β, interleukin-6, and tumor necrosis factor-α. Pretreatment with ASTE inhibited lipopolysaccharide-induced of IκBα degradation, p65 phosphorylation and up-regulation of Nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome proteins. Moreover, ASTE inhibited monosodium urate-induced the up-regulation of active caspase-1 and interleukin-1β, promoted nuclear factor E2-related factor2 (Nrf2) to translocate into the nucleus, reducing the generation of MSU-induced reactive oxygen species. These results suggested that ASTE alleviated gout inflammation via inhibiting NLRP3 inflammasome activation and activating Nrf2 signaling pathway. PRACTICAL APPLICATIONS: Artemisia selengensis Turcz (AST) as a common vegetable in China belongs to genus Artemisia, which are rich in di-caffeoylquinic acids. This study aimed to investigate the effect of ASTE on alleviating gout inflammation and whether NLRP3 inflammasome and Nrf2 signaling pathways are involved in the protection of ASTE against gout inflammation. Our findings are significant for developing di-CQAs from AST by-products as an effective functional food for preventing gout.

Phytochemical Characterization and Antioxidant and Enzyme Inhibitory Activities of Different Parts of Prinsepia utilis Royle

The objective of this study was to evaluate the phenolic composition and antioxidant and enzyme inhibitory activities of the flowers, leaves, and stems of Prinsepia utilis Royle. In the work, their total phenol content and flavonoid content were determined. In addition, the scavenging effects of DPPH and ABTS free radicals and ferric reducing antioxidant power were measured. The results showed the flowers had the highest total phenol and flavonoid content, followed by the leaves and stems. A total of 11 phenolic substances were identified and quantified using UHPLC-ESI-HRMS/MS, of which rutin was the dominant phenolic compound in all samples. All three samples had good antioxidant activity and dose dependently inhibited the activity of α-glucosidase, pancreatic lipase, and tyrosinase. In summary, the ethanol extracts of the flowers have the best antioxidant and enzyme inhibitory ability among three samples. The outcome could provide support for the development and utilization of P. utilis.

Chemical Composition and Phytotoxic Activity of Artemisia selengensis Turcz. Volatiles

The chemical profile and allelopathic action of the volatiles produced by Artemisia selengensis were studied. Artemisia selengensis was found to release volatile chemicals to the environment to influence other plants' growth, which suppressed the root length of Amaranthus retroflexus and Poa annua by 50.46 % and 87.83 % under 80 g/1.5 L treatment, respectively. GC/MS analysis led to the identification of 41 compounds (by hydrodistillation, HD) and 48 compounds (by headspace solid-phase microextraction, HS-SPME), with eucalyptol (15.45 % by HD and 28.09 % by HS-SPME) being detected as the most abundant constituent. The essential oil (EO) of A. selengensis completely inhibited the seed germination of A. retroflexus and P. annua at 1 mg/mL and 0.5 mg/mL, respectively. However, eucalyptol displayed much weaker activity compared with the EO, indicating that other less abundant constituents might contribute significantly to the EO's activity. Our study is the first report on the phytotoxicity of A. selengensis EO, suggesting that A. selengensis might release allelopathic volatile agents into the environment that negatively affect other plants' development so as to facilitate its own dominance; the potential value of utilizing A. selengensis EO as an environmentally friendly herbicide is also discussed.

The karyotype, genome survey, and assembly of Mud artemisia (Artemisia selengensis)

BACKGROUND

Artemisia selengensis is traditional Chinese medicine and phytochemical analysis indicated that A. selengensis contains essential oils, fatty acids and phenolic acids. The lack of reference genomic information may lead to tardiness in molecular biology research of A. selengensis.

METHOD AND RESULTS

Karyotype analysis, genome survey, and genome assembly was employed to acquire information on the genome structure of A. selengensis. The chromosome number is 2n = 2x = 36, karyotype formula is 28 m + 8Sm, karyotype asymmetry coefficient is 58.8%, and karyotypes were symmetric to Stebbins' type 2A. Besides, the flow cytometry findings reported that the mean peak value of fluorescent intensity is 1,170,677, 2C DNA content is 12 pg and the genome size was estimated to be approximately 5.87 Gb. Furthermore, the genome survey generates 341,478,078 clean reads, unfortunately, after K-mer analysis, no significant peak can be observed, the heterozygosity, repetitive rate and genome size was unable to estimated. It is speculated that this phenomenon might be due to the complexity of genome structure. 37,266 contigs are preliminary assembled with Oxford Nanopore Technology (ONT) sequencing, totaling 804 Mb and GC content was 34.08%. The total length is 804,475,881 bp, N50 is 29,624 bp, and the largest contig length is 239,792 bp.

CONCLUSION

This study reveals the preliminary information of genome size of A. selengensis. These findings may provide supportive information for sequencing and assembly of whole-genome sequencing and encourage the progress of functional gene discovery, genetic improvement, evolutionary study, and structural studies of A. selengensis.

Screening of Anti-Lipase Components of Artemisia argyi Leaves Based on Spectrum-Effect Relationships and HPLC-MS/MS

Pancreatic lipase is a key lipase for triacylglyceride digestion and absorption, which is recognized as a promising target for treatment of metabolic disorders. Natural phytochemicals are hopeful sources for pancreatic lipase inhibitors. The leaves of Artemisia argyi H.Lév. and Vaniot (AL) is commonly used as herbal medicine or food supplement in China and other Asian countries for hundreds of years. AL mainly contains essential oils, phenolic acids, flavonoids and terpenoids, which exhibit many pharmacological activities such as antioxidant, anti-inflammatory, antimicrobial, analgetic, anti-cancer, anti-diabetes and immunomodulatory effects. However, the anti-lipase activity of AL was lack of study and the investigation of anti-lipase ingredients from AL was also insufficient. In the present study, the anti-lipase activity of AL was evaluated in vitro and the potentially pancreatic lipase inhibitors of AL were investigated. High performance liquid chromatography was used to establish fingerprints of AL samples, and fifteen peaks were selected. The anti-lipase activities of AL samples were evaluated by a pancreatic lipase inhibition assay. Then, the spectrum-effect relationships between fingerprints and pancreatic lipase inhibitory activities were investigated to identify the anti-lipase constitutes in AL. As the results, four caffeoylquinic acids, which were identified as neochlorogenic acid, chlorogenic acid, isochlorogenic acid B, and isochlorogenic acid A by high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, were selected as potential pancreatic lipase inhibitors in AL. Moreover, anti-lipase activity assessment and molecular docking study of the four compounds were performed to validate the potential lipase inhibitors in AL. The results revealed that the four caffeoylquinic acids in AL as bioactive compounds displayed with anti-lipase activity. The present research provided evidences for the anti-lipase activity of AL, and suggested that some bioactive compounds in AL could be used as lead compounds for discovering of new pancreatic lipase inhibitors.

Integrated metabolomics and ligand fishing approaches to screen the hypoglycemic ingredients from four Coptis medicines

Rhizoma Coptidis, which is mainly originated from the rhizomes of Coptis chinensis, C. deltoidea, C. omeiensis and C. teeta, has been proved to possess a superior anti-diabetic effect in clinic. However, the metabolic characterization and the hypoglycemic ingredients among these Coptis species remain unclear. In this study, we employed an integrated strategy to screen the bioactive ingredients based on metabolomics and ligand fishing approaches. First, the ultra high-performance liquid chromatography coupled to quadruple time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) was used for qualitative identification of four Coptis rhizomes. After prescreening by α-glucosidase inhibition assay, an affinity ultrafiltration system was constructed to fish out hypoglycemic ingredients from the fractions with superior activity, and verified by molecular docking on a virtual platform. The distribution of major compounds suggested the four Coptis rhizomes possess similar metabolic profiles, mainly including alkaloids and phenylpropanoids. Besides, eight compounds (magnoflorine, groenlandicine, jatrorrhizine, epiberberine, columbamine, coptisine, palmatine and berberine) from the n-butanol fraction were specifically bound to α-glucosidase, and considered as hypoglycemic ingredients of Rhizoma Coptidis. Molecular docking revealed that the inhibitors bound to α-glucosidase mainly by hydrophobic interaction, hydrogen bond interaction and π-π interaction. Summary, this research leads a more systematic and comprehensive study on metabolic characterization and hypoglycemic ingredients of Rhizoma Coptidis, which can provide a theoretical basis for the further clinical application.

Ultrasound-Assisted Extraction Optimization of α-Glucosidase Inhibitors from Ceratophyllum demersum L. and Identification of Phytochemical Profiling by HPLC-QTOF-MS/MS

Ceratophyllum demersum L. (CDL) is a traditional Chinese herb to treat many diseases, but research on its anti-diabetic activity is not available. In this research, the α-glucosidase inhibitory ability and phytochemical constituents of CDL extract were firstly studied. Optimal ultrasound-assisted extraction conditions for α-glucosidase inhibitors (AGIs) were optimized by single factor experiment and response surface methodology (RSM), which was confirmed as 70% methanol, liquid-to-solid ratio of 43 (mL/g), extraction time of 54 min, ultrasonic power of 350 W, and extraction temperature of 40 °C. The lowest IC₅₀ value for α-glucosidase inhibition was 0.15 mg dried material/mL (mg DM/mL), which was much lower than that of acarbose (IC₅₀ value of 0.64 mg DM/mL). In total, 80 compounds including 8 organic acids, 11 phenolic acids, 25 flavonoids, 21 fatty acids, and 15 others were identified or tentatively identified from CDL extract by HPLC-QTOF-MS/MS analysis. The results suggested that CDL could be a potential source of α-glucosidase inhibitors. It can also provide useful phytochemical information for research into other bioactivities.

Sequential extraction and enrichment of flavonoids from Euonymus alatus by ultrasonic-assisted polyethylene glycol-based extraction coupled to temperature-induced cloud point extraction

A green method for simultaneous extraction and enrichment of flavonoids from Euonymus alatus was developed by ultrasonic-assisted extraction (UAE) and temperature-induced cloud point extraction (TICPE) using PEG-base aqueous solution as the extractant. Based on screening different molecular weights of PEGs, PEG-400/water was used as the extractant, and the effects of key factors on extraction yields of flavonoids were investigated by single-factor experiments and response surface methodology (RSM). The optimum conditions of UAE were as follows: PEG-400 concentration of 16% (w/w), particle size of 80 mesh, solvent-to-material ratio of 60:1, extraction temperature of 90 °C and extraction time of 15 min. The results obtained by validation experiments were consistent with the values predicted by RSM. Temperature-induced formation of the aqueous two-phase system (ATPS) and TICPE process were further investigated by controlling temperature and adding (NH₄)₂SO₄. In the presence of (NH₄)₂SO₄, the ATPS formed at 75 ℃ and pH 3.5 could effectively improve separation and recovery of flavonoids with enrichment factor of above five times. Gallic acid, catechin, dihydromyricetin and ellagic acid in the extract were identified and confirmed by UPLC-Q-TOF-MS and the corresponding standards. The UAE-TICPE coupled to HPLC was successfully applied for extraction and determination of flavonoids in two batches of Euonymus alatus. The extraction yields of catechin, dihydromyricetin and total flavonoids were 0.377-0.684 mg/g, 1.091-1.353 mg/g and 2.612-3.146 mg/g, respectively. Compared to conventional extraction methods, PEG-based UAE integrated with TICPE in one-step procedure exhibited higher extraction efficiency and better extraction selectivity.

Phytochemical composition of wormwood (Artemisia gmelinii) extracts in respect of their antimicrobial activity

BACKGROUND

Extracts from medicinal plants with phytochemicals with known antimicrobial properties can be an effective adjunct in the complex treatment of infectious diseases. This study aimed to evaluate the antimicrobial activity of wormwood extracts collected in Kazakhstan (Artemisia gmelinii Weber ex Stechm.), along with their phytochemical analysis.

METHODS

The ethanolic and chloroform extracts were subjected to HPLC combined with quadrupole time-of-flight mass spectrometry method. For quantitative assessment of antimicrobial activity, minimal inhibitory concentration (MIC) of the tested extracts was determined by micro-dilution broth method for the panel of the reference microorganisms. Minimal bactericidal concentration (MBC) or minimal fungicidal concentration (MFC) were also determined.

RESULTS

LC/MS analysis showed the presence of 13 compounds in the tested extracts, including flavonoids: apigenin, luteolin, rutin, two O-methylated flavonols (isorhamnetin, rhamnazine), coumarin compounds (umbelliferone, scopoletin and scopolin (scopoletin 7-glucoside), 3-hydroxycoumarin and 4-hydroxycoumarin), chlorogenic acid and two dicaffeoylquinic acid isomers. Quantitative HPLC analysis showed that umbelliferone was dominant in the chloroform extract while chlorogenic acid was identified as a main compound in the ethanolic extract. The antibacterial and antifungal activity of chloroform and ethanolic extracts was comparable. The most sensitive were the Gram-positive bacteria represented by staphylococci, Micrococcus luteus and Bacillus spp. (MIC = 1.25-5 mg/ml) and yeasts represented by Candida spp. (MIC = 2.5-5 mg/ml), irrespective of the assayed extract.

CONCLUSIONS

Extracts of wormwood Artemisia gmelinii have shown a wide spectrum of antibacterial and antifungal activity. Luteolin, rutin, isorhamnetin and scopolin were identified in A. gmelinii species for the first time. The determining of the most potential compounds of Artemisia gmelinii can be used to develop effective antibacterial and antifungal agents.

Phenolic Composition, Antioxidant Properties, and Inhibition toward Digestive Enzymes with Molecular Docking Analysis of Different Fractions from Prinsepia utilis Royle Fruits

The present study investigated the phenolic profiles and antioxidant properties of different fractions from Prinsepia utilis Royle fruits using molecular docking analysis to delineate their inhibition toward digestive enzymes. A total of 20 phenolics was identified and quantified. Rutin, quercetin-3-O-glucoside, and isorhamnetin-3-O-rutinoside were the major phenolic compounds in the total phenolic fraction and flavonoid-rich fraction. The anthocyanin-rich fraction mainly contained cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside. All of the fractions exhibited strong radical scavenging activities and good inhibition on cellular reactive oxygen species (ROS) generation in H₂O₂-induced HepG2 cells, as evaluated by DPPH and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Moreover, the powerful inhibitory effects of those fractions against pancreatic lipase and α-glucosidase were observed. The major phenolic compounds that were found in the three fractions also showed good digestive enzyme inhibitory activities in a dose-dependent manner. Molecular docking analysis revealed the underlying inhibition mechanisms of those phenolic standards against digestive enzymes, and the theoretical analysis data were consistent with the experimental results.

Comprehensive characterization and identification of antioxidants in Folium Artemisiae Argyi using high-resolution tandem mass spectrometry

Antioxidants from natural sources, such as vegetables and fruits, are attracting more and more interest. In this work, we evaluated the antioxidant potential of Folium Artemisia Argyi, a traditional Chinese herb medicine and food supplement. The total phenolic content, total flavonoid content, and antioxidant ability of the crude extracts and fractions obtained from consecutively partition of n-hexane, ethyl acetate, and n-butanol were measured and compared. Ethyl acetate fraction shows the highest total phenolic and flavonoid contents and highest antioxidant capability with regard to DPPH, ABTS, superoxide anion free radical scavenging ability, and ferric-reducing antioxidant power. In addition, the potential antioxidant components were screened by DPPH-UHPLC-MS experiments and subsequently characterized by using high-resolution tandem mass spectrometry. This work finally identified 45 antioxidants, including organic acids, phenolic compounds, flavonoids, and methoxylated flavonoids. The results suggested that Folium Artemisiae Argyi is a potential inexpensive resource of natural antioxidants.

Study of artemisinin and sugar accumulation in Artemisia vulgaris and Artemisia dracunculus "hairy" root cultures

We studied the effect of genetic transformation on biologically active compound (artemisinin and its co-products (ART) as well as sugars) accumulation in Artemisia vulgaris and Artemisia dracunculus "hairy" root cultures. Glucose, fructose, sucrose, and mannitol were accumulated in A. vulgaris and A. dracunculus "hairy" root lines. Genetic transformation has led in some cases to the sugar content increasing or appearing of nonrelevant for the control plant carbohydrates. Sucrose content was 1.6 times higher in A. vulgaris "hairy" root lines. Fructose content was found to be 3.4 times higher in A. dracunculus "hairy" root cultures than in the control roots. The accumulation of mannitol was a special feature of the leaves of A. vulgaris and A. dracunculus control roots. A. vulgaris "hairy" root lines differed also in ART accumulation level. The increase of ART content up to 1.02 mg/g DW in comparison with the nontransformed roots (up to 0.687 mg/g DW) was observed. Thus, Agrobacterium rhizogenes-mediated genetic transformation can be used for obtaining of A. vulgaris and A. dracunculus "hairy" root culture produced ART and sugars in a higher amount than mother plants.

LC-ESI-TOF-MS and GC-MS profiling of Artemisia herba-alba and evaluation of its bioactive properties

In this work, LC-ESI-TOF-MS and GC-EI-MS were used to assess the potential of Artemisia herba alba as a source of health-promoting constituents. Besides, the antioxidant, the antimicrobial and the cytotoxic potentials were evaluated. A total of 86 metabolites, including C-glycosylated and methylated flavones, quinic acid derivatives, coumarins, sesquiterpenes lactones, terpenoids, fatty acids, carbohydrates, organic acids and alkaloids were identified, sixty five of them were reported for the first time in A. herba alba. The main compounds were di-O-caffeoylquinic acids, artemisinic acid, menthol, α-ketoglutaric acid, scopolin, isoschaftoside and sucrose. Furthermore, results showed that A. herba alba possess high total antioxidant activity (Total antioxidant activity=423mg gallic acid equivalent/g dry weight), strong potential anticancer capacity against MCF-7 breast cancer and HeLa human cervical cell lines (IC₅₀ of 15 and 70μg/ml, respectively), and moderate antibacterial activity against S. aureus, B. thurigiensis and A. hydrophila. These results support the use of this plant as alternative bioactive ingredient for functional foods, dietary supplements or nutraceuticals.

Chlorogenic acids and the acyl-quinic acids: discovery, biosynthesis, bioavailability and bioactivity

This review is focussed upon the acyl-quinic acids, the most studied group within theca.400 chlorogenic acids so far reported.

A strategy for establishment of practical identification methods for Chinese patent medicine from systematic multi-component characterization to selective ion monitoring of chemical markers: Shuxiong tablet as a case study

A SMC-SIM strategy for establishment of practical identification methods for Chinese patent medicine.