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 505 records · Page 28Linked to original sources
PubMed1980

The location of a disulfonic stilbene binding site in band 3, the anion transport protein of the red blood cell membrane.

The binding site for 4,4'-diisothiocyano-2,2'-stilbenedi sulfonic acid, a specific, potent, irreversible inhibitor of anion transport in red blood cells is located in a 15 000 dalton transmembrane segment of band 3, produced by chymotrypsin treatment of ghosts stripped of extrinsic proteins. The segment was cleaved into three fragments of 7000 daltons by CNBr. The C-terminus of the segment is located in the 7000 daltons by the N-terminus in one of the 4000 dalton fragment; the N-terminus in one of the 4000 dalton fragments; and the binding site for 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid in the middle 4000 dalton fragment. The latter was cleaved by N-bromosuccinimide into two fragments of 2000 daltons. The binding site for 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid was located on the fragment containing the newly formed N-terminus. It is concluded that the binding site is located about 9000 daltons from the C-terminus (at the outside face of the membrane) and 6000 daltons from the N-terminus (at the cytoplasmic face). In view of the existing evidence that the binding site may be located near the outside face of the membrane, it is suggested that the 15 000 dalton segment is folded, so that it crosses the bilayer three times.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1981

Inhibition of anion permeability of sarcoplasmic reticulum vesicles by stilbene derivatives and the identification of an inhibitor-binding protein.

The permeability of sarcoplasmic reticulum vesicles to sulfate ions was inhibited by diisothiocyano-1,2-diphenylethane-2,2'-disulfonic acid (H2DIDS), which is a potent inhibitor of anion permeability in red blood cell membrane. The amount of H2DIDS bound to the vesicles was determined by using [3H]-H2DIDS. Apparent half inhibition of sulfate permeation was observed on the binding of 2.5 mumol/g protein. SDS-polyacrylamide gel electrophoresis on the vesicles treated with [3H]H2DIDS showed that about 10% of the total bound H2DIDS corresponds to a 100 000-dalton protein, but the remaining 90% to non-protein components. The content of the H2DIDS-binding protein was about 0.5 mumol/g protein. These results suggest that the H2DIDS-binding protein is different from the calcium pump protein and is possibly an anion transport system similar to band 3 in red blood cell membrane.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1989

Inhibition of inorganic anion transport across the human red blood cell membrane by chloride-dependent association of dipyridamole with a stilbene disulfonate binding site on the band 3 protein.

The inhibition of inorganic anion transport by dipyridamole (2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido[5,4-d] pyrimidine) takes place only in the presence of Cl-, other halides, nitrate or bicarbonate. At any given dipyridamole concentration, the anion flux relative to the flux in the absence of dipyridamole follows the equation: Jrel = (1 + alpha 2[Cl-])/(1 + alpha 4[Cl-]) where alpha 2 and alpha 4 are independent of [Cl-] but dependent on dipyridamole concentration. At high [Cl-] the flux approaches alpha 2/alpha 4, which decreases with increasing dipyridamole concentration. Even when both [Cl-] and dipyridamole concentration assume large values, a small residual flux remains. The equation can be deduced on the assumption that Cl- binding allosterically increases the affinity for dipyridamole binding to band 3 and that the bound dipyridamole produces a non-competitive inhibition of sulfate transport. The mass-law constants for the binding of Cl- and dipyridamole to their respective-binding sites are about 24 mM and 1.5 microM, respectively (pH 6.9, 26 degrees C). Dipyridamole binding leads to a displacement of 4,4'-dibenzoylstilbene-2,2'-disulfonate (DBDS) from the stilbenedisulfonate binding site of band 3. The effect can be predicted quantitatively on the assumption that the Cl- -promoted dipyridamole binding leads to a competitive replacement of the stilbenedisulfonates. For the calculations, the same mass-law constants for binding of Cl- and dipyridamole can be used that were derived from the kinetic studies on Cl- -promoted anion transport inhibition. The newly described Cl- binding site is highly selective with respect to Cl- and other monovalent anion species. There is little competition with SO4(2-), indicating that Cl- binding involves other than purely electrostative forces. The affinity of the binding site to Cl- does not change over the pH range 6.0-7.5. Dipyridamole binds only in its deprotonated state. Binding of the deprotonated dipyridamole is pH-independent over the same range as Cl- binding.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2004

3,4',5-Trihydroxy-trans-stilbene (resveratrol) inhibits human cytomegalovirus replication and virus-induced cellular signaling.

Resveratrol is a polyphenolic natural product that is present in red wine and peanuts and has inhibitory activity against inflammation, heart disease, and cancer. Here we describe its inhibition of human cytomegalovirus replication (IC50 = 1-2 microM). At least 50-fold higher concentrations of compound were required to produce cytotoxicity against growing or stationary human embryonic lung fibroblasts. Mechanism of action studies determined that resveratrol blocked virus-induced activation of the epidermal growth factor receptor (EGFR) and phosphatidylinositol-3-kinase signal transduction as well as NF-kappaB and Sp1 transcription factor activation shortly following infection. Resveratrol prevented the appearance of immediate-early, early, and late viral proteins. Human cytomegalovirus DNA replication was reduced to undetectable levels by treatment with resveratrol, as were the second (late) phases of virus-induced phosphatidylinositol-3-kinase signaling and transcription factor activation. Resveratrol lost substantial antiviral activity when its addition was delayed until 4 h postinfection. Compound reversibility and preincubation studies were inconsistent with a virucidal mechanism of action. These data indicated that this compound likely operated during attachment and entry. We hypothesize that the primary molecular target for resveratrol may be blockage of epidermal growth factor receptor activation and its downstream effectors.

Antiviral Agents↗
PubMed2006

Fate of a stilbene-type fluorescent whitening agent (DSBP) in the presence of Fe(III) aquacomplexes: from the redox process to the photodegradation.

The behaviour of 4,4'-bis(2-sulfostyryl)biphenyl (DSBP), a fluorescent whitening agent, was investigated in the presence of Fe(III) aquacomplexes at room temperature. In the dark, a two-step reaction was observed when adding Fe(III) to a solution of DSBP: an initial fast redox reaction between DSBP and the monomeric species Fe(OH)(2+) and a slower reaction leading to the coagulation of oxidised DSBP and iron. This phenomenon is due to the formation of a complex or an ion-pair between Fe(II) and/or Fe(III) with oxidised DSBP and it probably occurs by charge neutralisation in our experimental conditions. The precipitation of DSBP depends on the initial concentration in Fe(OH)(2+) and is achieved for a ratio [Fe(OH) (2+)]/[DSBP] of 5 approximately. Under irradiation at 365 nm, a complicated behaviour was observed: a complexation of iron by oxidised DSBP favoured by irradiation and a degradation of DSBP induced by an intramolecular electron transfer in the complex or by a photoredox of Fe(OH)(2+) species generating .OH radicals in the supernatant. The complete degradation of DSBP is reached four times faster in the presence of Fe(III) with respect to the direct photolysis of DSBP alone. Moreover, the total mineralization of DSBP obtained in less than 120 h upon irradiation at 365 nm is only observed in the presence of the ferric ions, enlightening the efficiency of the method involving Fe(III) and UV irradiation.

Ferric Compounds↗
PubMed2005

Magnetic resonance spectroscopic comparison of the effects of resveratrol (3,4',5-trihydroxy stilbene) to conjugated equine estrogen, tibolone and raloxifene on ovariectomized rat brains.

OBJECTIVE: To investigate the effects of resveratrol on basic cerebral metabolites of in the brains of ovariectomized rats. MATERIALS AND METHODS: Twenty-four bilaterally ovariectomized rats were randomly assigned into six groups with four rats in each group. The groups consisted of sham-operated (control), ovariectomized, resveratrol, conjugated equine estrogen (CEE), tibolone and raloxifene treated rats. Drug administration started at the 5th day following ovariectomy and continued for 35 days. At the end of the entire course, in vivo single voxel magnetic resonance spectroscopy was performed on whole brains to determine choline, creatine and N-acetyl aspartate (NAA) concentrations. RESULTS: Compared to sham-operated group, ovariectomized group had significantly lower NAA (P<0.008) but significantly higher choline levels (P<0.031). Administration of CEE and resveratrol resulted in NAA levels that were similar to those in the sham-operated group, showing that the NAA decrease due to ovariectomy was prevented. Treatment with tibolone and raloxifene resulted in a smaller increase in NAA and the effect failed to reach significance. Administration of resveratrol, CEE, tibolone and raloxifene resulted in choline levels similar to those in sham-operated group, showing that the increase in the ovariectomy group was prevented. CONCLUSION: Resveratrol causes levels of cerebral metabolites that is similar to conventional hormone replacement agents. This finding may suggest that neuronal function in the postmenopausal state was preserved. More detailed investigation of this issue should be the task of future research.

Animals↗