neoastilbin and astilbin

Topics: Binding Sites; Circular Dichroism; Cytochrome P-450 CYP3A; Flavonoids; Humans; Molecular Docking Simulation; Protein Binding; Spectrometry, Fluorescence; Thermodynamics

Astilbin, isoastilbin and neoastilbin are the three flavonoid isomers prevalent in Rhizoma Smilax glabra. The interactions between human cytochrome P450 2D6 (CYP2D6) and the three isomers were investigated by multiple spectroscopic coupled with molecular docking. As a result, the fluorescence intensity of CYP2D6 was quenched statically by the three isomers. Meanwhile, astilbin had the strongest binding ability to CYP2D6, followed by isoastilbin and neoastilbin under the identical temperature. Synchronous fluorescence, three-dimensional fluorescence, ultraviolet-visible spectroscopy, circular dichroism and Fourier-transform infrared spectra confirmed that the conformation and micro-environment of CYP2D6 protein were changed after binding with the three isomers. As suggested from molecular docking, the three isomers had strong binding affinity to CYP2D6 via the bonding of hydrogen and van der Waals forces, and the results were in agreement with the fluorescence results. The findings here suggested that astilbin, isoastilbin and neoastilbin may cause the herb-drug interactions for their inhibition of CYP2D6 activity.

Topics: Binding Sites; Circular Dichroism; Cytochrome P-450 CYP2D6; Flavonoids; Flavonols; Humans; Hydrogen Bonding; Molecular Docking Simulation; Protein Binding; Spectrometry, Fluorescence; Thermodynamics

Astilbin and neoastilbin are two flavonoid stereoisomers. In the present study, their solubility, stability, and bioavailability were compared in a rat. The results revealed that the water solubility of astilbin and neoastilbin was 132.72 μg/mL and 217.16 μg/mL, respectively. The oil-water distribution coefficient (log P) of astilbin and neoastilbin in simulated gastric fluid (SGF) was 1.57 and 1.39, and in simulated intestinal fluid (SIF) was 1.09 and 0.98, respectively. In SIF, about 78.6% astilbin remained after 4 h of incubation at 37 °C, while this value was 88.3% for neoastilbin. Most of the degraded astilbin and neoastilbin were isomerized into their cis-trans-isomer, namely neoisoastilbin and isoastilbin, respectively, and the decomposed parts were rare. For bioavailability comparison in a rat, an HPLC method for trace amounts of astilbin and neoastilbin determination in plasma was developed, and the pretreatment of plasma was optimized. A pharmacokinetic study showed that the absolute bioavailability of astilbin and neoastilbin in a rat showed no significant difference with values of 0.30% and 0.28%, respectively.

Topics: Biological Availability; Drugs, Chinese Herbal; Flavonoids; Flavonols; Humans; Smilax; Solubility

This study aimed to isolate, prepare and identify the main flavonoids from a standardized

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Benzothiazoles; Biphenyl Compounds; Catechin; Chromatography, High Pressure Liquid; Flavonoids; Flavonols; Glycosides; Lipopolysaccharides; Magnetic Resonance Spectroscopy; Mice; Picrates; RAW 264.7 Cells; Smilax; Sulfonic Acids

Astilbin is the most predominant flavonoid in Rhizoma Smilacis Glabrae (RSG) with many bioactivities. The interconversion of the astilbin and its three stereoisomers was found with incubation of RSG extract at different temperatures, and the equilibrium ratios were calculated. Under certain conditions, neoastilbin would replace astilbin and become the predominant flavonoid in RSG extract. The effects of ascorbic acid, sucrose, sodium benzoate, β-cyclodextrin (β-CD) and common metal ions on the isomerization and decomposition of astilbin were studied. Ascorbic acid showed the best protective effect on the decomposition of astilbin and its isomers, which may be attributed to its reducing and radical scavenging ability. Besides, ascorbic acid also accelerated the isomerization of astilbin. β-CD suppressed both isomerization and decomposition of astilbin through complexation between them. Most metal ions had inhibition effects on the isomerization of astilbin. Al

Topics: Drugs, Chinese Herbal; Flavonoids; Flavonols; Isomerism; Protective Agents; Rhizome; Stereoisomerism

A cell-permeable membrane, as typified by Transwell insert Permeable Supports, permit accurate repeatable invasion assays, has been developed as a tool for screening immunological active components in Smilacis Glabrae Rhizoma (SGR). In this research, components in the water extract of SGR (ESGR) might conjugate with the receptors or other targets on macrophages which invaded Transwell inserts, and then the eluate which contained components biospecific binding to macrophages was identified by HPLC-ESI-MS(n) analysis. Six compounds, which could interact with macrophages, were detected and identified. Among these compounds, taxifolin (2) and astilbin (4) were identified by comparing with the chromatography of standards, while the four others including 5-O-caffeoylshikimic acid (1), neoastilbin (3), neoisoastilbin (5) and isoastilbin (6), were elucidated by their structure clearage characterizations of tandem mass spectrometry. Then compound 1 was isolated and purified from SGR, along with 2 and 4, was applied to the macrophage migration and adhesion assay in HUVEC (Human Umbilical Vein Endothelial Cells) -macrophages co-incultured Transwell system for immunological activity assessment. The results showed that compounds 1, 2 and 4 with concentration of 5μM (H), 500nM (M) and 50nM (L) could remarkably inhibit the macrophage migration and adhesion (Vs AGEs (Advanced Glycation End Produces) group, 1-L, 2-H and 4-L groups: p<0.05; other groups: p<0.01). Moreover, 1 and 4 showed satisfactory dose-effect relationship. In conclusion, the application of macrophage biospecific extraction coupled with HPLC-ESI-MS(n) analysis is a rapid, simple and reliable method for screening immunological active components from Traditional Chinese Medicine.

Topics: Biological Factors; Cell Adhesion; Cell Movement; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Flavonoids; Flavonols; Human Umbilical Vein Endothelial Cells; Humans; Macrophages; Medicine, Chinese Traditional; Quercetin; Rhizome; Shikimic Acid; Smilax; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Water

The extracts of two medicinal plants used in traditionalmedicine against malariawere characterized by means of an LC‑SPE‑NMR and LC‑MS platform. The structure of a series of major constituents from Bafodeya benna, as well as minor constituents from Ormocarpum kirkii, was determined. Bafodeya benna was found to contain (2R,3R)-taxifolin-3-O-α-L-rhamnoside or astilbin, and its isomers neoastilbin, neoisoastilbin, and isoastilbin, as well as quercetin-3-O-α-L-rhamnoside. From Ormocarpum kirkii, a series of known flavonoids and biflavonoids was obtained, as well as three new compounds, i.e., 7,7′′-di-O-β-D-glucosyl-(−)-chamaejasmin, 7-O-β-D-glucosyl-(I-3,II-3)-biliquiritigenin, and isovitexin-(I-3,II-3)-naringenin. The isolated constituents may explain, at least in part, the traditional use against malaria. LC‑SPE‑NMR, in combination with LC‑MS, is a powerful tool for the fast characterization of plant extracts, in order to define priorities at an early stage of a fractionation procedure. In addition, herbal medicinal products can completely be characterized, both with regard to their major as well as their minor constituents.

Topics: Antimalarials; Biflavonoids; Chemical Fractionation; Chromatography, High Pressure Liquid; Chrysobalanaceae; Fabaceae; Flavonoids; Flavonols; Magnetic Resonance Spectroscopy; Malaria; Plant Extracts; Plant Leaves; Plants, Medicinal

To study the chemical constituents of the plant of Sarcandra glabra and provide reference for the study of the bioactive substances.. The compounds were isolated from the EtOH extract by various chromatographic methods and their structures were elucidated by their physico-chemical properties and the analysis of their spectral data.. Nine compounds were isolated and identified as isoscopletin (1), syringaresinol monoside (2), styraxjaponoside B (3), 5-O-caffeoylshikimic acid (4), shizukanolide E (5), isoastilbin (6), neoisoastilbin (7), astilbin (8), neoastilbin (9).. Compounds 1-7 were isolated from S. glabra for the first time.

Topics: Cholestenones; Drugs, Chinese Herbal; Flavonoids; Flavonols; Furans; Lignans; Magnoliopsida; Plant Bark; Plant Stems; Shikimic Acid

The structures of two flavanonol glycosides isolated from Smilax glabra, named smitilbin and neosmitilbin, have been revised to isoastilbin and neoastilbin, respectively. The revised structures were determined based on intensive studies of chemical interconversion, NMR spectroscopy, and X-ray crystallographic analysis. The latest NMR data were also summarized.

Topics: Flavonoids; Flavonols; Glycosides; Molecular Structure; Plant Extracts; Smilax

To study the chemical constituents of Bauhinia aurea.. The compounds were isolated by column chromatography over silica gel, reversed-phase RP-18, and Sephadex LH -20. MS and NMR spectroscopic methods were used to determine structures of purified compounds.. Eight compounds were isolated from the ethyl acetate soluble fraction of the ethanolic extract and their structures were elucidated as isoengeletin (1), astilbin (2), neoastilbin (3), isoastilbin (4), neoisoastilbin (5), (+)-catechin (6), (-)-epicatechin (7) and (-)-epicatechin 3-O-gallate (8).. Five compounds were isolated from this genus for the first time except for 2, 6 and 8.

Topics: Bauhinia; Catechin; Chromatography, Gel; Drugs, Chinese Herbal; Flavonoids; Flavonols; Magnetic Resonance Spectroscopy; Mass Spectrometry; Plant Stems; Plants, Medicinal