Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “STILBENES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources
PubMed2006

The effect of cicerfuran, an arylbenzofuran from Cicer bijugum, and related benzofurans and stilbenes on Leishmania aethiopica, L. tropica and L. major.

The effect of 3 arylbenzofurans and 7 stilbenes on the growth of Leishmania parasites and human monocytes was evaluated. Promastigotes from cultures of L. aethiopica, L. major and L. tropica were tested in the exponential phase of growth. All compounds were active at concentrations of 100 microg/mL within 6 hours. The 2-hydroxylstibene showed activity at a concentration < 1 microg/mL, with an LD (50) of 3 - 5 microg/mL after 48 hours of incubation. The most active compounds: cicerfuran, 2-hydroxy-2'-methyl-4',5'-methylenedioxystilbene, 2-hydroxy-2'-methoxy-4',5'-methylenedioxystilbene and 2-hydroxystilbene had even stronger activity against the temperature-induced amastigotes of L. aethiopica, with the latter having the highest relative potency against all three species. Leishmanicidal activity seemed to be associated with the level of oxygen substitution in each compound. The ratio between leishmanicidal activity on promastigotes and toxicity to human cells suggested that the compounds could be considered as leishmanicidal drug leads.

Animals↗
PubMed1995

Naturally occurring protein kinase C inhibitors; II. Isolation of oligomeric stilbenes from Caragana sinica.

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.

Cells, Cultured↗
PubMed2006

Ab initio treatment of time-resolved x-ray scattering: application to the photoisomerization of stilbene.

In this work we present a general theoretical outline for calculating time-dependent x-ray scattering signal changes from first principles. We derive a formalism for the description of atom-atom correlation functions as Fourier transforms of quantum-chemically calculated electron densities and show their proportionality to the molecular form factor. The formalism derived in this work is applied to the photoisomerization of stilbene. We can demonstrate that wide-angle x-ray scattering offers a possibility to study the changes in electron densities in nonperiodic complex systems, which renders it a suitable technique for the investigation of (bio)organic systems.

Computer Simulation↗
PubMed2002

A stilbene synthase from Japanese red pine (Pinus densiflora): implications for phytoalexin accumulation and down-regulation of flavonoid biosynthesis.

Stilbene synthase (STS) and chalcone synthase (CHS) are plant-specific polyketide synthases that play key roles in the stilbenoid and flavonoid biosyntheses, respectively. We have recently isolated from Pinus densiflora three STS cDNAs (PDSTS1, PDSTS2, and PDSTS3) and one CHS cDNA (PDCHSX). We then heterologously expressed these cDNAs in Escherichia coli and characterized their properties. An unusual STS isozyme, PDSTS3, lacks the common C-terminal extension of STS because of a frame-shift mutation and shows the highest pinosylvin-forming activity among the STSs tested. Pinosylvin was shown to be a potent inhibitor of PDCHSX (K(i) = 6 microM) as well as PDSTS2 (K(i) = 13 microM), which presumably maintains the balance between the stilbenoid and flavonoid biosyntheses. PDSTS3 was insensitive to product inhibition. We identified PDSTS3 in the pine seedlings as well as full-length STS. The data provide evidence that PDSTS3 is involved in the potential regulation of the stilbenoid and flavonoid biosynthetic pathways in pine trees.

Acyltransferases↗
PubMed1995

Co-expressed complementary fragments of the human red cell anion exchanger (band 3, AE1) generate stilbene disulfonate-sensitive anion transport.

We have constructed cDNA clones encoding various portions of the human red cell anion transporter (band 3), a well characterized integral membrane protein with up to 14 transmembrane segments. The biosynthesis, stability, cell surface expression, and functionality of these band 3 fragments were investigated by expression from the cRNAs into microsomal membranes using the reticulocyte cell-free translation system and in Xenopus oocytes. Co-expression of the pairs of recombinants encoding the first 8 and last 6 transmembrane spans (8 + 6) or the first 12 and last 2 spans (12 + 2) of band 3 generated stilbene disulfonate-sensitive anion transport in oocytes. When the pairs of fragments 8 + 6 or 12 + 2 were co-expressed with glycophorin A (GPA), translocation to the plasma membrane of the fragment corresponding to the first 12 or the first 8 transmembrane spans was greater than in the absence of GPA. Only the fragment encoding the first 12 transmembrane spans showed GPA-dependent translocation when expressed in the absence of its complementary fragment. A truncated form of band 3 encoding all 14 transmembrane spans but lacking the carboxyl-terminal 30 amino acids of the cytoplasmic tail did not induce anion transport activity in oocytes and was not translocated to the plasma membrane but appeared to be degraded in oocytes. Our results suggest that there is no single signal for the insertion of the different transmembrane spans of band 3 into membranes and that the integrity of the loops between transmembrane spans 8-9 or 12-13 is not essential for anion transport function. Our data also suggest that a region of transmembrane spans 9-12 of band 3 is involved in the process by which GPA facilitates the translocation of band 3 to the surface.

Amino Acid Sequence↗
PubMed2000

A new stilbene dimer--shegansu B from Belamcanda chinensis.

A new dimeric stilbene, named shegansu B (1) was isolated from the ethanolic extract of the roots of Belamtantida chinensis (L.) DC., along with the known compounds isorhapontigenin, resveratol, p-hydroxybenzoic acid, iridin, tectoridin, tectorigenin and daucosterol. The structures were elucidated by means of spectroscopic evidence including 2D-NMR studies.

Chromatography↗
PubMed2001

Four new stilbene dimers from the lianas of Gnetum hainanense.

Four new stilbene dimers, gnetuhainins P (1), Q (2), K (3) and L (4), were isolated from the lianas of Gnetum hainanense C. Y. Cheng. Their structures and relative configurations were determined on the basis of spectroscopic evidence, especially 2D NMR techniques.

China↗
PubMed2005

Stilbene derivatives from Gnetum cleistostachyum.

Three new stilbene derivatives, named gnetucleistol A (1), B (2) and C (3), together with four known compounds, gnetifolin A (4), p-hydroxycinnamic acid (5), piceatannol (6) and resveratrol (7), were isolated from Gnetum cleistostachyum C.Y. Cheng (Gnetaceae). Their structures were elucidated on the basis of spectroscopic evidence (EI-MS, UV, IR, NOE, 1H, 13C and 2D NMR).

Chromatography, Gel↗
PubMed2005

A new diterpenoid and active stilbenes from Pinus armandii heartwood.

8(17),13-Labdadien-16,14-olid-18-oic acid (1), a new diterpenoid, has been isolated from the heartwood of Pinus armandii Francher, along with seven known diterpenoids (2-8) and four known stilbenes (9-12). Their structures have been elucidated by spectral evidence. (E)-3-Hydroxy-5-methoxystilbene (9) showed significant inhibition against white-rot fungi.

Diterpenes↗
PubMed2004

Stilbene derivatives with antifungal and radical scavenging properties from the stem bark of Artocarpus nobilis.

Antifungal activity-guided fractionation of the n-butanol extract from the methanol extract of the stem bark of Artocarpus nobilis furnished two stilbene derivatives (E)-4-isopentenyl-3,5,2',4'-tetrahydroxystilbene and (E)-4-(3-methyl-E-but-1-enyl)-3,5,2',4'-tetrahydroxystilbene. Both compounds showed strong antifungal activity against Cladosporium cladosporioides and high radical scavenging activity towards the DPPH radical in TLC bio-autography method.

Antifungal Agents↗
PubMed2005

Bioactive stilbene dimers from Gnetum cleistostachyum.

Two new stilbene dimers, named bisisorhapontigenin A (1) and cis shegansu B (2), together with gnetuhainin P (3) and gnetulin (4), were isolated from the lianas of Gnetum cleistostachyum C. Y. Cheng. Their structures were elucidated by means of spectroscopic evidences, including UV, IR, MS, 1H NMR, 13C NMR, NOE and 2D NMR, respectively. The pharmacological activities of compounds 1, 2 and 3 also have been tested.

Animals↗
PubMed1988

Mitochondria can import artificial precursor proteins containing a branched polypeptide chain or a carboxy-terminal stilbene disulfonate.

A purified, artificial precursor protein was used as a transport vehicle to test the tolerance of the mitochondrial protein import system. The precursor was a fusion protein consisting of mouse dihydrofolate reductase linked to a yeast mitochondrial presequence; it contained a unique cysteine as its COOH-terminal residue. This COOH-terminal cysteine was covalently coupled to either a stilbene disulfonate derivative or, with the aid of a bifunctional cross-linker, to one of the free amino groups of horse heart cytochrome c. Coupling to horse heart cytochrome c generated a mixture of branched polypeptide chains since this cytochrome lacks a free alpha-amino group. Both adducts were imported and cleaved by isolated yeast mitochondria. The mitochondrial protein import machinery can thus transport more complex structures and even highly charged "membrane-impermeant" organic molecules. This suggests that transport occurs through a hydrophilic environment.

Biological Transport↗
PubMed1985

Voltage-dependent chloride conductance of the squid axon membrane and its blockade by some disulfonic stilbene derivatives.

When giant axons of squid, Sepioteuthis, were bathed in a 100 mM Ca-salt solution containing tetrodotoxin (TTX) and internally perfused with a solution of 100 mM tetraethylammonium-salt (TEA-salt) or tetramethylammonium-salt (TMA-salt), the membrane potential was found to become sensitive to anions, especially Cl-. Membrane currents recorded from those axons showed practically no time-dependent properties, but they had a strong voltage-dependent characteristic, i.e., outward rectification. Cl- had a strong effect upon the voltage-dependent membrane currents. The nonlinear property of the currents was almost completely suppressed by some disulfonic stilbene derivatives applied intracellularly, such as 4-acetoamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) and as 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), which are blockers of chloride transport. On the basis of these experimental results, it is concluded that a voltage-dependent chloride-permeable channel exists in the squid axon membrane. The chloride permeability (PCl) is a function of voltage, and its value at the resting membrane (Em = -60 mV) is calculated, using the Goldman-Hodgkin-Katz equation, to be 3.0 X 10(-7) cm/s.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1981

Modulation of the covalent binding of aryl hydrocarbon metabolites to DNA in vitro after treatment of rats and mice with trans-stilbene oxide.

The effect of trans-stilbene oxide (TSO) induction on the microsome-catalyzed binding of polycyclic aromatic hydrocarbon metabolites to DNA was investigated using two rodent species (Sprague-Dawley rat and C57BL/6N or NMRI Swiss mouse) and 2 different binding substrates (benzo[a]anthracene). It was determined that TSO exerts 2 separate effects on polycyclic aromatic hydrocarbons - it increases the rate of oxidation at the K-region of the molecule due to its induction of specific monooxygenases, and it increases the rate of deactivation of epoxide intermediates by induction of microsomal epoxide hydrolase activity. The importance of these individual effects were determined by inducing monooxygenase activity with BP, altering region specificity and inducing epoxide hydrolase (EH) activity with TSO, assessing the combined inductive effects of TSO and BP, inhibiting EH with 1,1,1-trichloropropene oxide, or increasing its activity by the addition of pure enzyme. This study shows that these effects are similar for both substrates examined, and that the effect of TSO on the binding to DNA of highly carcinogenic bay-region diol-epoxides is multi-faceted, due to its multiple inductive effects.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

In vitro tolerance to Botrytis cinerea of grapevine 41B rootstock in transgenic plants expressing the stilbene synthase Vst1 gene under the control of a pathogen-inducible PR 10 promoter.

Resveratrol is a major phytoalexin in grapevine but its synthesis in response to phytopathogen attack decreases with grape berry ripening. A chimeric gene combining an alfalfa PR 10 promoter and Vst1 (Vitis stilbene synthase 1) gene was introduced into the genome of 41B rootstock. Transgenic plants were analysed for resveratrol production in leaves infected with Botrytis using an in vitro test. Among the 50 transgenic lines analysed, some exhibited a production lower than the non-transgenic control, but others accumulated resveratrol from 5-100-fold. Moreover, in the latter clones, symptoms were highly reduced in response to infection. These results were a good indication that the combination of a pathogen-inducible promoter and a defence gene may increase tolerance against fungi in grapevine. The efficacy of this approach should be further tested by experiments conducted in the vineyard.

Acyltransferases↗
PubMed2001

Trans-stilbene oxide-induced sister chromatid exchange in cultured human lymphocytes: influence of GSTM1 and GSTT1 genotypes.

About 50% and 15% of Caucasians lack the glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) genes and the corresponding enzyme activity, respectively. Both of these polymorphisms have been shown to affect the genotoxicity of some epoxides in cultured human lymphocytes. Especially GSTT1 appears to be important in whole-blood cultures, probably because GSTT1 activity is high in erythrocytes. The in vitro genotoxicity of trans-stilbene oxide (TSO), a model substrate for GSTM1, has been shown to depend on individual GSTM1 activity. The potential role of GSTM1 genotype, and the possible interference of GSTT1 genotype, has not previously been examined in this context. We have studied TSO-induced sister chromatid exchanges (SCEs) in 72 h whole-blood lymphocyte cultures from 24 healthy human donors, representing different combinations of GSTM1 and GSTT1 positive and null genotypes. TSO clearly increased SCEs in cultures of all donors. The mean number of SCEs per cell induced by 75 and 150 microM TSO was, respectively, 1.5- and 1.3-times higher in cultures of GSTM1 null than GSTM1 positive donors. In another experiment, GSTM1 null individuals showed, in comparison with GSTM1 positive subjects, a 1.8-fold SCE induction by 50 microM TSO. GSTT1 genotype did not have an unequivocal effect. Our findings suggest that the lack of the GSTM1 gene, resulting in reduced detoxification capacity, increases individual sensitivity to the genotoxic effects of TSO.

Adult↗
PubMed1989

Disulfonic stilbene derivatives open the Ca2+ release channel of sarcoplasmic reticulum.

Ca2+ channels of isolated sarcoplasmic reticulum were incorporated into a planar lipid bilayer and their pharmacological properties were studied. The results show that the channel is a Ca2+-induced Ca2+ release channel like that observed in skinned muscle fibers and isolated vesicles. (i) The open channel probability was increased by the addition of micromolar amounts of Ca2+ to the cis (myoplasmic) side and further increased by millimolar ATP. (ii) The channel was closed by millimolar Mg2+ and micromolar ruthenium red. We found that two disulfonic stilbene derivatives, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) and 4-acetoamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS), when added to the cis side open the channel and lock it irreversibly at open without changing the single channel conductance. Ca2+ efflux from SR vesicles was also enhanced by SITS and DIDS, as monitored by a tracer assay. Further, Ag+ activated the channel transiently. These results suggest that certain amino and SH residues play important roles in gating the Ca2+ channel.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1991

Structural requirements for the in vitro transformation of Syrian hamster embryo cells by stilbene estrogens and triphenylethylene-type antiestrogens.

The mechanisms of estrogen-induced cancer are still a matter of debate. Previous studies with stilbene estrogens and steroidal estrogens have shown that the in vitro transformation of primary Syrian hamster embryo (SHE) fibroblasts is a good experimental system for discriminating hormonal from nonhormonal events. We have now extended these studies to the triphenylethylene-type antiestrogens tamoxifen (TAM), 3-hydroxy-TAM, 4-hydroxy-TAM and 3,4-dihydroxy-TAM. Furthermore, a structural isomer of diethylstilbestrol (DES) with the hydroxy groups shifted into the meta-positions (3,3'-DES) was included. Our data clearly show that TAM and 4-hydroxy-TAM give rise to morphologic and neoplastic transformation of SHE cells in culture. In contrast, neither 3-hydroxy-TAM nor 3,3'-DES led to a significant transformation, in spite of the fact that both compounds are hormonally active. These results support the notion that nonhormonal events are essential for SHE cell transformation and suggest certain structural features to be necessary for the transforming capability. The putative carcinogenicity of TAM and 4-hydroxy-TAM but not of 3-hydroxy-TAM, as implied by these in vitro transformation studies, is corroborated by recent reports on ovarian and Leydig cell tumors in mice and hepatocellular carcinomas in rats.

Animals↗