Tresylates

Figure 14.14 Additional hydroxyl-particle activation methods include bis-epoxide modification, tosyl activation, and tresyl activation methods. The tosyl chloride and tresyl chloride activation procedures must be done in dry organic solvent, but the coupling of an amine-containing ligand can be done in either organic solvent or aqueous buffer.

This enzyme oxidizes a- and P-anomers of D-glucose to the same extent and shows excellent stability and sensitivity about twice that for the methods with immobilized glucose oxidase. In this approach, pyranose oxidase is immobilized on tresylate-poly(vinylalcohol) beads and packed into a stainless column and peroxidase is immobilized on tresylate-hydrophylic vinyl polymer beads and packed into a transparent FITE tube that is used as the CL flow cell. The H202... 

Similar to the work described by Spohn et al. [34], a trienzyme sensor was developed recently for the determination of branched-chain amino acids (L-valine, L-leucine, and L-isoleucine). Leucine dehydrogenase, NADH oxidase, and peroxidase were coimmobilized covalently on tresylate-hydrophylic vinyl polymer beads and packed into a transparent PILL tube (20 cm X 1.0 id), which was used as flow cell. The sensor was free of interferences from protein and NH4+ and it was stable for 2 weeks. The sensor system was applied to the determination of branched-chain amino acids in plasma with recoveries ranging from 98 to 100% [36],... 

Tresyl chloride/tosyl chloride method, for covalent ligand immobilization, 6 396t Tretinoin, 25 789... 

Cyanogen bromide method A,A -Carbonyl diimidazole method Divinylsulfone method Epoxy (bisoxirane) method Ethyldimethylaminopropyl carbodiimide method Eluoromethylpyridinium toluenesulfonate method A-hydroxysuccinimide ester method Schiff base (reductive amination) method Tresyl chloride/tosyl chloride method Sulfhydryls Azalactone method (for azalactone supports)... 

Tresyl chloride/tosyl chloride method Sulfhydryl groups ... 

Soluble enzymes, unless stated otherwise. Enzyme immobilized on tresyl-activated Sepharose. 

King and Gill have been studying the reaction of alkyl 2,2,2-trifluoroethanesulfonate esters (tresylates) (308) in aqueous base (pH >9) in the presence of a primary or secondary amine.282 Reaction with hydroxide is found to be a reversible ElcB process and reaction with water is the normal sulfonic ester hydrolysis. 

Choe, Y. S. Katzenellenbogen, J. A. TBAF-induced conversion of tresylates to mesylates. Tetrahedron Lett. 1993, 34, 1579-1580. 

King, J. F. Gill, M. S. Alkyl 2,2,2-trifluoro-ethanesulfonates (tresylates) elimination-addition vs bimolecular nucleophilic substitution in reactions with nucleophiles in aqueous media./. Org. Chem. 1996, 61, 7250-7255. 

TosoHass Tresyl toyopearl Heparin, cibacron blue, iminodiacetate... 

Reaction of surface hydroxyl groups with 2,2,2-trifluoroethanesulfonyl chloride (tresyl chloride) yields sulfonate esters which in a subsequent step can be reacted with amino- or mercapto-modihed biomolecules for covalent immobilization... 

F]Fluoropyrrolidine has been synthesized142 (equation 64) from the corresponding p-toluenesulphonate, methanesulphonate, 2,2,2-trifluoroethanesulphonate (tresylate) or trifluoromethanesulphonate (triflate) with K[18F]/K222 in MeCN. The involvement of difluoroethene143 has been proposed to explain the results obtained with the tresylate (equation 65). 

The most commonly used biopolymers, such as agarose, contain alcoholic hydroxyl groups which can be activated with cyanogen bromide however, better methods have recently been developed including activation with sulfonyl chlorides (17), 2-fluoro-l-methylpyridinium toluene sulfonate (FMP) (10), and chlorocarbonates (18). The first two are commercially available as activated supports tresyl-activated Sepharose (Pharmacia) and FMP-Trisacryl (BioProbe International). The newer methods yield more stable bonds, which preclude leaching of the enzyme from the matrix. Most of these activated supports are too expensive for commercial use in a large process bioreactor however, they may be extremely useful for preparing analytical bioreactors. 

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