Stilbene Oligomers Research Articles

Quantitative Determination of Stilbene Oligomers in Jin Que-gen Collected from Different Regions by a HPLC Method

The objectives of this research were to determine simultaneously the contents of two stilbene tetramers, carasinol B (1) and kobophenol A (2), and one stilbene trimer, (+)-alpha-viniferin (3), in Jin Que-gen in different regions. A HPLC method has been developed for efficiently quantifying the three analytes in the plant. Using this method, different samples of Jin Que-gen were evaluated. The results showed that contents of the three analytes varied significantly among different samples, and the contents of the three analytes in commercial Jin Que-gen were markedly lower than those in the plants collected directly from growing regions. And for the three analytes, the longer the cultivation time, the higher the contents.

Stilbenoids with One Epoxy Group from Cotylelobium lanceolatum

A phytochemical investigation of an acetone extract of Cotylelobium lanceolatum stem resulted in the isolation of two orange pigments-two stilbene trimer derivatives, cotylelophenols D and E and an artifact derivative, cotylelophenol F. The structure and relative configuration were confirmed by ID and 2D NMR spectral data. Cotylelophenols D and E are the first examples of stilbene oligomers bearing an epoxy group. The biogenetic relationships between the isolates are also discussed.

Oligomeric Stilbenes from the Root of Caragana stenophylla.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Three new resveratrol oligomers from the stem bark of Vatica pauciflora.

Three new stilbene oligomers (1-3) were isolated from the stem bark of Vatica pauciflora. The structures of a resveratrol heptamer (pauciflorol D) (1), a resveratrol dimer (pauciflorol E) (2), and an indanone derivative (pauciflorol F) (3) were elucidated by means of spectroscopic data interpretation, especially HMBC and NOESY NMR experiments.

Two New Resveratrol (=5‐[(1E)‐2‐(4‐Hydroxyphenyl)ethenyl]benzene‐1,3‐diol) Tetramers with a Tetrahydrofuran Ring from Dipterocarpus grandiflorus

AbstractTwo new stilbene tetramers, grandiphenols A (1) and B (2), along with ten known stilbene oligomers and bergenin were isolated from the stem of Dipterocarpus grandiflorus. The structures of 1 and 2 composed of four resveratrol (=5‐[(1E)‐2‐(4‐hydroxyphenyl)ethenyl]benzene‐1,3‐diol) units had eight asymmetric C‐atoms in the partial structures of a tetrahydrofuran and two dihydrobenzofuran moieties. Detailed spectroscopic analyses, especially HMBC and NOESY experiments, allowed to differentiate the configurations of 1 and 2.

New Resveratrol Dimer Glucosides and Trimers in Stem and Root of Welwitschia mirabilis

Two new resveratrol dimer glucosides, mirabilosides A (1) and B (2), and two new resveratrol trimers, mirabilols A (3) and B (4) were isolated from stem and root of Welwitschia mirabilis (Welwitschiaceae) together with four known stilbene oligomers (gnetins C, E, F and I). The structures of isolated compounds were determined by spectroscopic analysis.

Oligomeric Stilbenes from the Root of Caragana stenophylla

Caragaphenol A (1), a new trimeric stilbene, was isolated from the roots of Caragana stenophylla (Leguminosae) along with three known oligomeric stilbenes: (+)-alpha-viniferin (2), miyabenol C (3) and kobophenol A (4). The stereostructure of 1 was elucidated by one- and two-dimensional (1D- and 2D-)-NMR spectral studies.

特異なポリフェノール―植物スチルベンオリゴマーの化学と多様な生物活性

特異なポリフェノール―植物スチルベンオリゴマーの化学と多様な生物活性

Stilbene Derivatives from Two Species of Gnetaceae

AbstractFor Abstract see ChemInform Abstract in Full Text.

Diptoindonesin A, a new C-glucoside of ε-viniferin from Shorea seminis (Dipterocarpaceae)

A new C-glucoside of ε-viniferin, named diptoindonesin A ( 1), was isolated from the ethyl acetate extract of the tree bark of Shorea seminis, together with the known stilbene oligomers (−)-ampelopsin A ( 2), (−)-α-viniferin ( 3), and (−)-hopeaphenol ( 4). The structure of 1 was determined from spectroscopic evidence.

Four New Stilbene Oligomers in the Root of Gnetum gnemon

Four new stilbene oligomers, gnemonols G, H, I, and J (1–4), were isolated from acetone extract of the root of Gnetum gnemon along with five known stilbenoids, ampelopsin E, cis-ampelopsin E, gnetins C, D, and E. The structures were elucidated on the basis of spectroscopic evidence.

Levels of Stilbene Oligomers and Astilbin in French Varietal Wines and in Grapes during Noble Rot Development

Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Stilbenes have been shown to have cancer chemopreventive activity and to protect lipoproteins from oxidative damage. A method for the direct determination of stilbene oligomers (viniferin and pallidol) as well as astilbin in different types of wine using high-performance liquid chromatography with UV detection is described. In a survey of 21 commercial wines from the south of France, levels of pallidol and viniferin are reported for the first time in different types of wines. Viniferin was found to be present only in red and botrytized sweet white wines with levels between 0.1 and 1.63 mg/L; pallidol was not found in dry and sweet white wines but only in wines made by maceration with stems, with levels between 0.38 and 2.22 mg/L. Highest levels of astilbin were found in Egiodola (15.13 mg/L), Merlot (11.61 mg/L), and Cabernet Sauvignon (8.24 mg/L) for red wines and in Sauvignon (5.04 mg/L) for white varietal wines. Astilbin levels are highest for recent vintages, but pallidol is not found in older vintages. During noble rot development in Sauvignon or Sémillon grapes from the Sauternes area, levels of trans-astringin, trans-resveratrol, trans-piceid, and pallidol are quite low (<0.5 mg/kg of grapes). Viniferin and astilbin levels become optimum at 2 and 30 mg/kg, respectively, during spot grape and speckle grape stages.

Stilbene derivatives from two species of Gnetaceae.

Five new stilbene oligomers (gnemonols A, B and C, gnemonoside E and gnetal) were isolated together with 2b-hydroxyampelopsin F and gnetin E from Gnetum gnemon and G. gnemonoides. The structures of the compounds were elucidated on the basis of spectral evidence.

(+)-Alpha-viniferin, a stilbene trimer from Caragana chamlague, inhibits acetylcholinesterase.

In the course of screening natural products for anti-acetylcholinesterase (AChE) activity, we found that a total methanolic extract of the underground parts of Caragana chamlague (Leguminosae) had significant inhibition towards AChE. Bioactivity-guided fractionation of the total methanolic extract resulted in the isolation and identification of two active stilbene oligomers, (+)-alpha-viniferin (1) and kobophenol A (2). Both 1 and 2 inhibited AChE activity in a dose-dependent manner, and the IC50 values of 1 and 2 were 2.0 and 115.8 microM, respectively. The AChE inhibitory activity of 1 was specific, reversible and noncompetitive.

Determination of hypaphorine and oligomeric stilbenes in the root of Caragana sinica by capillary electrophoresis with electrochemical detection

Capillary electrophoresis with electrochemical detection (CE-ED) was employed for the determination of hypaphorine (an alkaloid) and four oligomeric stilbenes (including pallidol, kobophenol A, miyabenol C and (+)-α-viniferin) in Radix seu Cortex Caraganae Sinicae, the root of Caragana sinica (Buc'hoz) Rehd. The effects of several important factors were investigated to find optimum conditions. The working electrode was a 300 μm diameter carbon disc electrode positioned opposite the outlet of capillary. The five analytes could be well separated within 12 min in a 40 cm length capillary at the separation voltage of 12 kV in a 100 mmol l −1 borate buffer (pH 10.0). The response was linear over about three orders of magnitude for all investigated compounds with detection limits ( S/ N=3) ranging from 0.0385 to 0.111 mg l −1. This proposed method has also been successfully applied to analyze the root of other Caragana plants.

Six New Heterocyclic Stilbene Oligomers from Stem Bark of Shorea hemsleyana

Six New Heterocyclic Stilbene Oligomers from Stem Bark of Shorea hemsleyana

Stilbene oligomers in roots of Sophora davidii

Three stilbene oligomers, davidiols A–C were isolated from the roots of Sophora davidii in addition to the seven known phenols, leachianone A, sophoraflavanones G, H and I, miyabenol C, α-viniferin and ε-viniferin. Their structures and relative configurations were established by means of 2D-NMR spectroscopy including COLOC and PSNOESY.

Resveratrol-type oligostilbenes from Iris clarkei antagonize 20-hydroxyecdysone action in the Drosophila melanogaster B(II) cell line.

Bioassay-guided high-performance liquid chromatography analysis of a MeOH extract of Iris clarkei seeds yielded the resveratrol-type oligomeric stilbenes, ampelopsin B and alpha-viniferin, which antagonize the action of 20-hydroxyecdysone; with a 20-hydroxyecdysone concentration of 50 nM, the ED50 values were 33 microM and 10 microM, respectively. The structures of these compounds were determined by spectroscopic analysis, notably ultraviolet, liquid secondary ion mass spectrometry and modern one- and two-dimensional nuclear magnetic resonance techniques.

Alpha-viniferin: a prostaglandin H2 synthase inhibitor from root of Carex humilis.

An inhibitor on cyclooxygenase activity of prostaglandin H2 synthase was purified from the root of Carex humilis Leyss (Cyperaceae) by a variety of column chromatographic methods. As a result of the structure analysis by FAB-mass, 1H-NMR, and 13C-NMR spectral data, the active compound was identified as (+)-alpha-viniferin, an oligomeric stilbene characterized originally from Caragana chamlagu Lamarck (Leguminosae). (+)-alpha-Viniferin exhibited a dose-dependent inhibition on cyclooxygenase activity, where 50% of inhibition (IC50) was shown at a final concentration of about 7 microM. Resveratrol, a putative building block of oligomeric stilbenes, also inhibited the cyclooxygenase activity. The inhibitory potency of (+)-alpha-viniferin was about 3- to 4-fold stronger than that of resveratrol on cyclooxygenase activity of prostaglandin H2 synthase partially purified from sheep seminal vesicles.

Naturally Occurring Protein Kinase C Inhibitors; II1. Isolation of Oligomeric Stilbenes fromCaragana sinica2

The oligomeric stilbenes (+)-alpha-viniferin (1), miyabenol C (2), and kobophenol A (3) have been isolated from Caragana sinica (Buchoz) Rehd (Leguminosae). (+)-alpha-Viniferin (1) and miyabenol C (2) exhibited protein kinase C inhibitory activity at low micromolar concentrations. (+)-alpha-Viniferin inhibited keratinocyte proliferation (0.4 microM) and free radical release in whole blood (47 microM), in vitro, and may be useful in treating hyperproliferative or inflammatory skin diseases.