Organic amine groups

SCHEME 8.10 Syntheses of bifunctional mesoporous silica nanoparticles having sulfonic acid groups on the internal surface and organic amine groups on the external surface. 

The synthesis of sulfosuccinate esters—either monoesters or diesters—or the corresponding amides is usually done in a two-step procedure. In both cases, the MA is reacted in the first step with organic alcohol, organic amine, or (in the case of monoesters) with other suitable organic reactants that bear hydroxyl (or even protic) groups in the second step sulfation of the maleic ester takes place. 

ABNP is soluble in dimethylformamide (DMF) but insoluble directly in aqueous solution. Insulin labeling was done in DMF water at a ratio of 9 1. For molecules not soluble in organic solvent, such as proteins, the trifunctional first may be dissolved in DMF and a small aliquot added to an aqueous reaction medium. The nitrophenyl ester reactive group can be coupled to amine groups at alkaline pFI (7-9) and in buffers containing no extraneous amines (avoid Tris). Unfortunately, ABNP is not commercially available at the time of this writing. 

The NHS ester end of NHS-LC-biotin reacts with amine groups in proteins and other molecules to form stable amide bond derivatives (Figure 11.4). Optimal reaction conditions are at a pH of 7-9, but the higher the pH the greater will be the hydrolysis rate of the ester. Avoid amine-containing buffers which will compete in the acylation reaction. NHS-LC-biotin is insoluble in aqueous reaction conditions and must be solubilized in organic solvent prior to the addition of a small quantity to a buffered reaction. Preparation of concentrated stock solutions may be done in DMF or DMSO. Nonaqueous reactions also may be done with this reagent for the modification of molecules insoluble in water. The molar ratio of NHS-LC-biotin to a... 

Organic phosphorus associations can occur under both acidic and basic conditions. Phosphorus can form esters with organic alcohol functional groups and can be associated with amine groups in various ways. 

Crooks et al. reported the transfer of amine-functionalized poly(amidoamine) dendrimers into toluene containing dodecanoic acid [198], The method is based on the formation of ion pairs between the fatty acids and the terminal amine-groups. These dendrimer-fatty acid complexes resemble unimolecular inverted micelles and could be used as phase transfer vehicles for the transport of Methyl Orange, an anionic dye molecule, into an organic medium. 

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