- The assembly of rotaxane-like dye/cyclodextrin/surface complexes on aluminium trihydroxide or goethite
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Simple azo-dyes carrying phosphonic acid and arsonic acid substituents such as 4-(4′-hydroxyphenyl azo)phenylphosphonic acid (5) and 4-(4′-hydroxyphenylazo)phenylarsonic acid (6) bind more strongly to high surface area oxides such as aluminium trihydroxide and goethite than their carboxylic and sulfonic acid analogues and the phosphonate-functionalized dyes have been shown to have greater humidity fastness when printed onto commercial alumina-coated papers. Adsorption isotherm measurements provide evidence for the formation of ternary dye/cyclodextrin/surface complexes. Dyes which form such ternary complexes show higher light fastness when printed onto alumina coated papers in an ink formulation containing α-cyclodextrin. The Royal Society of Chemistry 2006.
- Cooper, Rachel J.,Camp, Philip J.,Gordon, Ross J.,Henderson, David K.,Henry, Dorothy C. R.,McNab, Hamish,De Silva, Sonali S.,Tackley, Daniel,Tasker, Peter A.,Wight, Paul
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p. 2785 - 2793
(2007/10/03)
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- Attachment of phosphonate-functionalised azo-dyes to oxide surfaces to give enhanced light and wet fastness.
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Phosphonate-functionalised dyes have been shown to bind strongly to aluminium oxides and to form stable 1:1 complexes with cyclodextrins at the surface.
- De Silva, Sonali S,Camp, Philip J,Henderson, David K,Henry, Dorothy C R,McNab, Hamish,Tasker, Peter A,Wight, Paul
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p. 1702 - 1703
(2007/10/03)
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- Structure-activity relationships of pyridoxal phosphate derivatives as potent and selective antagonists of P2X1 receptors
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Novel analogues of the P2 receptor antagonist pyridoxal-5′-phosphate 6-azophenyl-2′,5′ disulfonate (2) were synthesized and studied as antagonists in functional assays at recombinant rat P2X1, P2X2, and P2X3 receptors expressed in Xenopus oocytes (ion flux stimulation) and at turkey erythrocyte P2Y1 receptors (phospholipase C activation). Selected compounds were also evaluated as antagonists of ion flux and the opening of a large pore at the recombinant human P2X7 receptor. Modifications were made in the 4-aldehyde and 5′-phosphate groups of the pyridoxal moiety: i.e. a CH2OH group at the 4-position in pyridoxine was either condensed as a cyclic phosphate or phosphorylated separately to form a bisphosphate, which reduced potency at P2 receptors. 5-Methylphosphonate substitution, anticipated to increase stability to hydrolysis, preserved P2 receptor potency. At the 6-position, halo, carboxylate, sulfonate, and phosphonate variations made on the phenylazo ring modulated potency at P2 receptors. The p-carboxyphenylazo analogue, 4, of phosphate 2 displayed an IC50 value of 9 nM at recombinant P2X1 receptors and was 1300-, 16-, and > 10000-fold selective for P2X1 versus P2X2, P2X3, and P2Y1 subtypes, respectively. The corresponding 5-methylphosphonate was equipotent at P2X1 receptors. The 5-methylphosphonate analogue containing a 6-[3,5-bis(methylphosphonate)]phenylazo moiety, 9, had IC50 values of 11 and 25 nM at recombinant P2X1 and P2X3 receptors, respectively. The analogue containing a phenylazo 4-phosphonate group, 11, was also very potent at both P2X1 and P2X3 receptors. However, the corresponding 2,5-disulfonate analogue, 10, was 28-fold selective for P2X1 versus P2X3 receptors. None of the analogues were more potent at P2X7 and P2Y1 receptors than 2, which acted in the micromolar range at these two subtypes.
- Kim,Brown,Harden,Boyer,Dubyak,King,Burnstock,Jacobson
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p. 340 - 349
(2007/10/03)
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- PREPARATION D'AMINOPHENYL-, NITROPHENYL-, PYRIDYL-, ET QUINOLYLPHOSPHONATES SOUS PHOTOSTIMULATION OU ASSISTANCE METALLIQUE; ACCES AUX ACIDES AMINOPHOSPHONIQUES CORRESPONDANTS
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Our aim was to study the aromatic nucleophilic substitution between the sodium anion of diethylphosphite and several halogenated substrates like: iodo-anilines, iodo-nitrobenzenes, bromo- and iodopyridines, bromoquinoline.Two coupling processes have been evaluted.The first one is the photostimulated nucleophilic substitution (SRN1), the second the promoted arylation by transition metals.We obtain good results with the first method which is efficient and simple; by contrast the second one has given only few positive results.We describe five aromatic aminophosphonic acids.
- Bulot, J. J.,Aboujaoude, E. Elia,Collignon, N.,Savignac, P.
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p. 197 - 204
(2007/10/02)
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