apigenin-7-o-glucuronide and scutellarin

Scutellarin is the major and active constituent of Dengzhan Xixin Injection (DZXX), a traditional Chinese medicine prepared from the aqueous extract of Erigeron breviscapus and widely used for the treatment of various cerebrovascular diseases in clinic. In present study, the possible pharmacokinetic differences of scutellarin after intravenous administration of scutellarin alone or DZXX were explored. Additional, the potential roles of β-glucuronidase (GLU) and OATP2B1 in drug-drug interaction (DDI) between scutellarin and constituents of DZXX were further evaluated in vitro. The plasma concentration, urinary and biliary excretion of scutellarin in rats after administration of DZXX, were significantly higher than those received scutellarin, while pharmacokinetic profile of Apigenin 7-O-glucuronide (AG) in rats was similar no matter AG or DZXX group. Furthermore, higher concentration in brain and plasma, however, lower level of scutellarin in intestine were observed after intravenous administration of DZXX. Finally, AG and caffeoylquinic acid esters were found to significantly inhibit GLU and OATP2B1 in vitro, which might explain, at least in part, the pharmacokinetic DDI between scutellarin and other chemical constituents in DZXX. The findings provided deep insight into the prescription-formulating principle in DZXX for treating the cerebrovascular diseases.

Topics: Animals; Apigenin; Bile; Drug Compounding; Drug Interactions; Endocytosis; Erigeron; Glucuronates; Glucuronidase; HEK293 Cells; Humans; Hydrolysis; Injections, Intravenous; Male; Organic Anion Transporters; Plant Extracts; Rats, Sprague-Dawley; Tissue Distribution

A general protocol for direct glucuronic linkages formation featuring Au(I)-catalyzed appropriately protected glucuronyl o-alkynylbenzoate-involved glycosylation reaction, as well as a concise approach for easy access of scutellarein prominent for the mild and efficient hydroxyl group installation via borylation-oxidation sequence from flavanone derivative, has been established, based on which a novel route for scutellarin derivatives preparation has been devised. The developed strategies, among which the stepwise deprotection process was also included, guarantee the high whole synthetic efficiency, and definitely will find broad application in diversity-oriented synthesis of bioactive flavonoid glycosides.

Topics: Apigenin; Glucuronates; Molecular Structure

To study the absorption characteristics of Xinshao extracts in Caco-2 cells. In this paper, human colon adenocarcinoma cell line Caco-2 cell model was established, and UPLC-MS method was applied to determinate the contents of five components of Xinshao extracts(albiflorin, gallic acid, caffeic acid, scutellarin and apigenin-7-O-glucronide) in cell lysates. This model was also used to study the effect of different drug concentrations, pH, time and temperature on the absorption of five components, investigate the transport of the five components of Xinshao extracts under the conditions with or without P-glycoprotein inhibitors, and predict the absorption mechanism of these five components in Caco-2 cells. The experimental results showed that the absorption of five components of Xinshao extracts in Caco-2 cells was time-dependent at 37 ℃, and concentration-dependent in the range of 0.5-12.5 g•L⁻¹, with a passive diffusion mechanism. At the pH of 4-7.4, the absorption of caffeic acid, scutellarin and apigenin-7-O-glucronide was significantly declined with the increase of pH(P<0.05). At the temperature of 4 to 37 ℃, the absorption of caffeic acid was declined with the increase of temperature, while the absorption of other four components was increased with the increase of temperature. Compared with the control group, caffeic acid and scutellarin cell absorption was significantly higher(P<0.05) after treatment with P-glycoprotein inhibitors(verapamil and cyclosporine A). The results indicated that, the absorption mechanism of five components in Xinshao extracts may be of passive diffusion, and the caffeic acid and scutellarin may be the substrates of P-glycoprotein.

Topics: Apigenin; ATP Binding Cassette Transporter, Subfamily B, Member 1; Biological Transport; Caco-2 Cells; Caffeic Acids; Cyclosporine; Drugs, Chinese Herbal; Glucuronates; Humans; Intestinal Absorption; Verapamil

Scutellarein-7-O-beta-D-glucuronide (SG) and apigenin-7-O-beta-D-glucuronide (AG) are two major bioactive constituents with known pharmacological effects in Erigeron multiradiatus. In this study, a simple method for preparative separation of the two flavone glucuronides was established with macroporous resins. The performance and adsorption characteristics of eight macroporous resins including AB-8, HPD100, HPD450, HPD600, D100, D101, D141, and D160 have been evaluated. The results confirmed that D141 resin offered the best adsorption and desorption capacities and the highest desorption ratio for the two glucuronides among the tested resins. Sorption isotherms were constructed for D141 resin under optimal ethanol conditions and fitted well to the Freundlich and Langmuir models (R(2) > 0.95). Dynamic adsorption and desorption tests was performed on column packed with D141 resin. After one-run treatment with D141 resin, the two-constituent content in the final product was increased from 2.14% and 1.34% in the crude extract of Erigeron multiradiatus to 24.63% and 18.42% in the final products with the recoveries of 82.5% and 85.4%, respectively. The preparative separation of SG and AG can be easily and effectively achieved via adsorption and desorption on D141 resin, and the method developed can be referenced for large-scale separation and purification of flavone glucuronides from herbal raw materials.

Topics: Adsorption; Apigenin; Erigeron; Glucuronates; Hydrogen-Ion Concentration; Kinetics; Porosity; Resins, Synthetic; Solutions; Temperature

Erigeron multiradiatus (Lindl.) Benth., an herb that grows in the alpine and subalpine meadow of Qinghai-Tibet plateau, has been widely used as a folk remedy by the native people for treatment of various inflammatory ailments.. In order to isolate and identify the active components of Erigeron multiradiatus for anti-inflammatory activity, a preliminary phytochemical study and a bioassay-guided fractionation and purification process was performed.. The dry whole plant Erigeron multiradiatus was extracted with 50% ethanol and then separated into CHCl(3), n-BuOH, and aqueous fractions. The anti-inflammatory activities of each fraction were investigated using two in vivo inflammation models.. These results exhibited varying degrees of anti-inflammatory activities and the n-BuOH fraction showed the strongest anti-inflammatory activities. The n-BuOH fraction was then subjected to separation and purification using macroporous resins column chromatography and Sephadex LH-20 leading to two flavonoids glucuronides identified as scutellarein-7-O-beta-glucuronide and apigenin-7-O-beta-glucuronide. Furthermore, LC-MS/MS identification and quantification of isolated compounds were also performed.. Scutellarein-7-O-beta-glucuronide and apigenin-7-O-beta-glucuronide were considered as major components and principally responsible for the anti-inflammatory activity of Erigeron multiradiatus. Thus the results of our study provide a scientific basis for the utilization of Erigeron multiradiatus in traditional Tibetan medicine.

Topics: Animals; Anti-Inflammatory Agents; Apigenin; Biological Assay; Disease Models, Animal; Edema; Erigeron; Female; Flavonoids; Glucuronates; Inflammation; Male; Medicine, Tibetan Traditional; Mice; Plant Extracts; Rats; Rats, Sprague-Dawley; Tibet

An HPLC-DAD-MS method was developed for simultaneous determination of the five major active constituents in Erigeron multiradiatus (Wall.) Benth, namely 6'-O-cafferylerigeroside (1), scutellarin (2), apigenin-7-O-beta-d-glucuronide (3), apigenin (4) and kaempferol (5), respectively. They were identified by ESI-MS and comparisons with literature. A comprehensive validation of the method included tests of sensitivity, linearity, precision and accuracy. The linear regressions were acquired with r>0.999. The precision was evaluated by intra- and inter-day assays, and relative standard deviation (R.S.D.) values were reported within 2.7%. The recovery studies for the quantified compounds were observed in the range of 95.3-102.4% with R.S.D. values less than 2.3%. The overall procedure may be suitable for the qualitative and quantitative analyses of a large number of E. multiradiatus samples. Hierarchical clustering analysis based on the characteristics of the 5 investigated compound peaks in HPLC profiles showed that 18 samples were divided into 2 main clusters. The clusters corresponded to their content. The five constituents in E. multiradiatus are generally regarded as an index for the quality assessment of this herb.

Topics: Apigenin; Calibration; Chromatography, High Pressure Liquid; Cluster Analysis; Erigeron; Glucuronates; Hot Temperature; Kaempferols; Linear Models; Mass Spectrometry; Molecular Structure; Plant Extracts; Pyrones; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization; Time Factors