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At least 685 records · Page 38Linked to original sources
PubMed1992

A red cell band 3 variant with altered stilbene disulphonate binding is associated with the Diego (Dia) blood group antigen.

1. We have shown that the Dia antigen of the Diego blood group system is associated with the presence of red cell band 3 Memphis, but not all band 3 Memphis samples carry the Dia antigen. 2. The band 3 Memphis associated with the Dia antigen was covalently labelled by 4,4'-di-isothiocyanato-1,2-diphenylethane-2,2'-disulphonic acid (H2DIDS) more readily than was normal band 3 or band 3 Memphis not associated with the Dia antigen. This altered reactivity with H2DIDS has previously been noted for a band 3 Memphis sub-type designated variant 2. 3. This is the first example of a band 3 polymorphism associated with an antigenic change in the extracellular region of the band 3 polypeptide and with altered H2DIDS binding.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2005

The gene stlA encodes a phenylalanine ammonia-lyase that is involved in the production of a stilbene antibiotic in Photorhabdus luminescens TT01.

Photorhabdus is a genus of Gram-negative bacteria from the family Enterobacteriaceae. Members of Photorhabdus have a complex life cycle during which the bacterium has a pathogenic interaction with insect larvae whilst also maintaining a mutualistic relationship with nematodes from the family Heterorhabditidae. During growth in the insect, Photorhabdus bacteria produce a broad-spectrum antibiotic identified as 3,5-dihydroxy-4-isopropylstilbene (ST). The biochemical pathway responsible for the production of this antibiotic has not been characterized. In this report, a mutant strain of Photorhabdus luminescens subsp. laumondii TT01, BMM901, has been isolated, by transposon mutagenesis, that is unable to produce the ST antibiotic. Using in silico studies, feeding experiments and biochemical analyses, it is shown that the gene mutated in this strain, stlA, encodes phenylalanine ammonia-lyase (PAL). PAL catalyses the non-oxidative deamination of l-phenylalanine to trans-cinnamic acid and the enzyme is ubiquitous in plants, where it is involved in the production of phenylpropanoids such as lignin and phytoalexins. However, this is the first report of PAL activity in a member of the Proteobacteria.

Anti-Bacterial Agents↗
PubMed2003

A cis-stilbene derivative.

The title compound, 4'-methoxy-alpha,2,3',4-tetranitrostilbene, C(15)H(10)N(4)O(9), crystallizes in the centrosymmetric space group P2(1)/c with one molecule in the asymmetric unit. The phenyl rings are inclined to one another and form a dihedral angle of 57.4 (1) degrees. The size of this angle is a result of intermolecular C-H...O interactions involving the phenyl H atoms. The torsion angle between the phenyl rings, -7.5 (3) degrees, indicates a cis geometry between them. The methoxy group is almost coplanar with the phenyl ring, and the nitro groups are twisted with respect to the phenyl rings because of the short H...O contacts. The crystal packing is stabilized by C-H...O hydrogen bonds, and the intermolecular hydrogen bonds form a C(12) graph-set chain running along the [010] direction.

Journal Article↗
PubMed1996

Development of bioactive functions in Hydrangeae dulcis folium. VI. Syntheses of thunberginols A and F and their 3'-deoxy-derivatives using regiospecific lactonization of stilbene carboxylic acid: structures and inhibitory activity on histamine release of hydramacrophyllols A and B.

Lactonization reaction of 2-carboxystilbene mediated by copper(II) chloride proceeded regiospecifically to give the five-membered lactone, while the bromolactonizations using N-bromosuccinimide and anodic oxidation were found to furnish the six-membered lactone. Using these regiospecific lactonization reactions as a key step, antiallergic and antimicrobial isocoumarins and the benzylidenephthalides thunberginols A and F and their 3'-deoxyanalogs were synthesized from phyllodulcin and hydrangenol. Two phthalides called hydramacrophyllols A and B were isolated from Hydrangeae Dulcis Folium and their stereostructures were determined on the basis of physicochemical and chemical evidence, which included the syntheses of hydramacrophyllols A and B from hydrangenol by the application of the lactonization method using copper(II) chloride. In addition, hydramacrophyllols A and B were found to exhibit an inhibitory effect on the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.

Animals↗
PubMed1996

Effects of stilbene derivatives SITS and DIDS on development of intracellular acidosis during ischemia in isolated guinea pig ventricular papillary muscle in vitro.

Using ion-selective microelectrode techniques, we investigated the effects of 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid (SITS) and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), which are known as Cl(-)-HCO3- exchange blockers, on action potentials and intracellular pH (pHi) in guinea pig ventricular papillary muscles subjected to simulated ischemia. Simulated ischemia was produced by stopping the flow of superfusing solution and then covering the preparations with mineral oil. Simulated ischemia induced a progressive decrease in the maximum upstroke rate and resting membrane potentials, shortened action potential duration, and resulted in cessation of action potentials within 10-12 min after the onset of simulated ischemia. The pHi-measurements revealed progressive intracellular acidosis during the period of simulated ischemia. SITS (0.5 mM) or DIDS (0.1 mM) delayed the onset of ischemia-induced deterioration of action potentials and prolonged the time to cessation of action potentials. SITS or DIDS (0.1-0.5 mM) induced an increase in pHi in HCO3(-)-buffered solution and suppressed the development of intracellular acidosis during ischemia. Under the external Cl(-)-free condition, the time to cessation of action potentials caused by ischemia was significantly delayed, and the development of intracellular acidosis during ischemia was attenuated. The present results indicate that activation of the Cl(-)-HCO3- exchange system would be involved, in part, in the development of intracellular acidosis during cardiac ischemia.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2001

Base sequence-specific attack of stilbene estrogen metabolite(s) on the mitochondrial DNA: implications in the induction of instability in the mitochondrial genome in the kidney of Syrian hamsters.

We have demonstrated previously that diethylstilbestrol is metabolized to diethylstilbestrol reactive metabolites by mitochondrial enzymes in vitro. In vitro, these reactive intermediates bind to mitochondrial DNA. Here we have investigated the in vivo formation of diethylstilbestrol adducts with mitochondrial DNA, the nature of mitochondrial DNA-diethylstilbestrol adducts, and the influence of diethylstilbestrol adduction on in vitro replication of a mitochondrial gene. Diethylstilbestrol administration to male hamsters produced several adducts in mitochondrial DNA of both kidney and liver. The total relative adduct levels were 5- to 6-fold higher in mitochondrial DNA than in nuclear DNA. The chromatographic mobility of mitochondrial DNA adducts formed in vivo were similar to that of dGMP-DES quinone adducts formed in vitro. The identity of mitochondrial DNA adducts formed in vivo was further confirmed as dGMP-diethylstilbestrol quinone adducts by rechromatography and cochromatography. Using a DNA polymerase arrest assay we found that the DES quinone attack on a mitochondrial respiratory gene, i.e., the gene for subunit III of cytochrome c oxidase (COIII), was specific for guanine residues that were adjacent to cytosine residues. Long-term treatment with diethylstilbestrol produced tumors in the kidney, and the level of COIII transcripts was 5- to 10-fold higher in tumor samples than age-matched control kidneys. These findings suggest that i) mitochondrial DNA appears more susceptible to formation of diethylstilbestrol adducts than nuclear DNA, ii) the DNA adducts formed by DES were predominantly with guanines, iii) the adducted bases stopped DNA polymerase-mediated in vitro replication of the COIII gene, and iv) long-term exposure of hamsters to diethylstilbestrol elevated the expression of COIII mRNA. These results suggest that obstruction of replication of the mitochondrial genes by covalent modifications of the mitochondrial DNA by diethylstilbestrol may produce mitochondrial genomic instability in vivo and may provide an explanation for the DES-induced mitochondrial structural abnormality.

Animals↗
PubMedDate not supplied

Stilbene estrogen produces higher levels of mitochondrial DNA adducts than nuclear DNA adducts in the target organ of cancer (liver) of male Sprague Dawley rats.

We have previously demonstrated that diethylstilbestrol is metabolized to diethylstilbestrol reactive metabolites by mitochondrial enzymes in vitro. In vitro, these reactive intermediates bind to mitochondrial DNA. Here we have investigated the in vivo formation of diethylstilbestrol adducts with mitochondrial DNA and the nature of mitochondrial DNA-diethylstilbestrol adducts. Diethylstilbestrol exposure to male rats produced several adducts in mitochondrial DNA of both kidney and liver. The total relative adduct levels were 7-fold higher in mitochondrial DNA than in nuclear DNA in the target organ of cancer (liver) of Sprague Dawley rats. The chromatographic mobility of mitochondrial DNA adducts formed in vivo were similar to that of dGMP-DES quinone adducts formed in vitro. These findings suggest that mitochondrial DNA appears more susceptible to formation of diethylstilbestrol adducts than nuclear DNA, and the results suggest that obstruction of replication and/or transcription of the mitochondrial genes by covalent modifications of the mitochondrial DNA by diethylstilbestrol may produce mitochondrial genomic instability in vivo and may provide an explanation for the carcinogenic effects of DES.

Animals↗
PubMed1994

Band 3 Memphis variant II. Altered stilbene disulfonate binding and the Diego (Dia) blood group antigen are associated with the human erythrocyte band 3 mutation Pro854-->Leu.

Band 3 Memphis is a commonly occurring polymorphic form of the human red cell anion transporter (band 3, AE1). Band 3 Memphis migrates more slowly on an SDS-polyacrylamide gel than normal band 3 and results from a point mutation Lys56-->Glu. Two types of band 3 Memphis, variants I and II, can be distinguished by their susceptibility to covalent labeling with H2DIDS (4,4'-diisothiocyanato-2,2'-dihydrostilbene disulfonate). Memphis variant II is more readily labeled than Memphis variant I or normal band 3. The Memphis variant II is also associated with the presence of the Diego (Dia) blood group antigen on the red cells. We have shown that Memphis variant II carries the polymorphism Pro854-->Leu, as well as Lys56-->Glu. The blood group antigen (Dia) present at the surface of Memphis variant II type red cells suggests the mutation Pro854-->Leu causes a change in the structure of an extracellular loop of Memphis variant II band 3. We discuss possible ways in which the mutation Pro854-->Leu affects the reactivity of Lys539 to covalent reaction with H2DIDS.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1994

Effects of inhibitors on anion exchangers in rabbit renal brush border membrane vesicles.

Cl-formate, Cl-oxalate, and SO4-CO3 exchange participate in Cl and organic anion transport across the brush border membrane of the rabbit proximal tubule. To determine the functional similarity of these transporters to each other and to band 3, we characterized, in isolated membrane vesicles, the inhibition of these transporters by compounds known to inhibit erythrocyte band 3. 4,4'-Dinitro-2,2'-disulfonic stilbene (DNDS), diphenylamine-2-carboxylate (DPC), flufenamate, and 4-aceto-4'-isothiocyano-2,2'-disulfonic stilbene (SITS) were effective inhibitors of Cl-oxalate and SO4-CO3 exchange, suggesting at least some common structural motifs between these exchangers and band 3. Cl-formate exchange was relatively insensitive to DNDS and DPC but sensitive to flufenamate (IC50 = 43 microM). Sensitivity to DNDS but not 4-amino-4'-amino-2,2'-disulfonic stilbene, a feature of band 3, was seen only for the SO4-CO3 exchanger. None of the exchangers had significant affinity for dipyridamole, furosemide, or probenecid. Finally, the presence of DPC or flufenamate increased the IC50 for reversible inhibition by DNDS, consistent with at least a partial overlap between the disulfonic stilbene and diphenylamine carboxylate binding sites of the Cl-oxalate exchanger. We next examined the effect of irreversible SITS binding. The Cl-oxalate exchanger was inhibited 90%, consistent with its high affinity for reversible inhibition by stilbenes. SITS pretreatment caused 50% inhibition of the Cl-formate exchanger, consistent with the reduced affinity of this exchanger for reversible binding of stilbenes. Despite the high sensitivity of the SO4-CO3 exchanger to reversible inhibition by stilbenes, SITS pretreatment caused < 20% irreversible inhibition of this exchanger. Finally, we characterized the stilbene inhibition of the Cl-oxalate exchanger in more detail. The presence of oxalate increased the IC50 for reversible inhibition by DNDS or SITS, implying that oxalate can directly compete at the reversible stilbene binding site of the Cl-oxalate exchanger. However, oxalate could not protect against covalent inactivation of the Cl-oxalate exchanger by SITS, indicating the presence of a separate site for irreversible binding of disulfonic stilbenes. These results suggest a dissociation between the sensitivities of proximal tubule anion exchangers to reversible and irreversible inhibition by disulfonic stilbenes. In contrast to band 3, the Cl-oxalate exchanger must possess separate sites for reversible and irreversible interaction with stilbenes, with only the former overlapping the substrate binding site.

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