Disulfonate binding

Phthalocyanine Dyes. In addition to their use as pigments, the phthalocyanines have found widespread appHcation as dyestuffs, eg, direct and reactive dyes, water-soluble dyes with physical or chemical binding, solvent-soluble dyes with physical or chemical binding, a2o reactive dyes, a2o nonreactive dyes, sulfur dyes, and wet dyes. The first phthalocyanine dyes were used in the early 1930s to dye textiles like cotton (qv). The water-soluble forms Hke sodium salts of copper phthalocyanine disulfonic acid. Direct Blue 86 [1330-38-7] (Cl 74180), Direct Blue 87 [1330-39-8] (Cl 74200), Acid Blue 249 [36485-85-5] (Cl 74220), and their derivatives are used to dye natural and synthetic textiles (qv), paper, and leather (qv). The sodium salt of cobalt phthalocyanine, ie. Vat Blue 29 [1328-50-3] (Cl 74140) is mostly appHed to ceUulose fibers (qv). 

Vanadate transport in the erythrocyte was shown to occur via facilitated diffusion in erythrocyte membranes and was inhibited by 4,4 -diisothiocyanostilbene-2,2 -disulfonic acid (DIDS), a specific inhibitor of the band 3 anion transport protein [23], Vanadium is also believed to enter cells as the vanadyl ion, presumably through cationic facilitated diffusion systems. The divalent metal transporter 1 protein (called DMT1, and also known as Nramp2), which carries iron into cells in the gastrointestinal system and out of endosomes in the transferrin cycle [24], has been proposed to also transport the vanadyl cation. In animal systems, specific transport protein systems facilitate the transport of vanadium across membranes into the cell and between cellular compartments, whereas the transport of vanadium through fluids in the organism occurs via binding to proteins that may not be specific to vanadium. 

The third method for the detection of ion flow through vesicle membranes works with the large population of a vesicular solution and is based on fluorescence measurements of calcein or similar water-soluble, ion-binding dyes. A macrocyclic a, -disulfone gives extremely long-lived, electroneutral vesicle... 

Studies with isolated renal brush-border membrane indicate that uptake is a carrier-mediated process, resulting in both transport into intravesicular space and binding to membrane surfaces. The process was saturable with K = 25.1 1.6 pM, and dependent on physiological pH. The inhibition by probenecid and organic anion transport inhibitor—4,4-diiso-thiocyanatos-tilbene-2,2-disulfonic acid (DIDS), 4-acetomido-4-isothiocyanatostilbebe-2,2-disulfonic acid (SITS)— was corroborated. 

Arimori et al. have used compounds 77 and 78 with 1,5- or 2,6-anthraquinone disulfonates (ADS) in a competitive system for the fluorescence detection of o-fruc-tose [146]. 1,5- or 2,6-ADS binds with 77 or 78 and quenches the fluorescence addition of D-fructose causes decomplexation and fluorescence recovery. 

On treatment with potassium iodide, the capped disulfonate j8-cyclo-dextrin discussed above could easily be converted to the corresponding diiodide jS-cyclodextrin. With appropriate nucleophiles (imidazole, histamine) a new route to bis(iV-imidazolyl)-j8-cyclodextrin and bis(iV-histamino)-j8-cyclodextrin was developed by Tabushi s team (182). In the presence of Zn(II) ion, both regiospecifically bifunctionalized cyclodextrins hydrate CO2 and are the first successful carbonic anhydrase models. The Zn(II) ion binds to the imidazole rings located in the edge of the cyclodextrin pocket and the presence of an additional basic group, as with bis(histamino)-cyclodextrin-Zn(II), enhances the activity. Therefore, the present models show that all three factors, Zn(II)-imidazole, hydrophobic environment, and a base seem to help to generate the carbonic anhydrase activity (182). The chemistry of this enzyme is further discussed in Section 6.2, p. 331. 

Kim et al. also synthesized PAEK bearing a pendant sulfonic acid group by reacting the activated carboxylic group with 2-aminoethanesulfonic acid or with the cross-linker disulfonic acid-benzidine diamines. The MEAs were fabricated for the cell performance test. CSPAEK membrane was inserted between the two electrodes, Pt/Ru (1/1) anode and Pt cathode, at the amount of 1.0 mg cm each. Nation solution (5 wt.%) was used to bind the membrane and catalyst. MEA was prepared under application of high pressure (1000 psi) for 1 min at 100°C. The cell test was conducted at 80°C. Methanol (2 M) was introduced at the anode side at 5 mL min and the oxygen to the cathode side at 200 mL min. The cell area was 6.25 cm . The maximum power density of Naflon 117 was 66.5 mW cm , whereas the 20% cross-linked membrane showed better performance, 71 mW cm . All the membranes OCVs equal to that of Naflon 117. 

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