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10180 dPEG 4-SATA acid(S-acetyl-dPEG 4-acid)

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CAS: 1263044-79-6

Item Name: dPEG 4-SATA acid(S-acetyl-dPEG 4-acid)

Item #: 10180

Mol. Wt.: 324.39;

single compound dPEG Spacer is 16 atoms and 18.3 A

10180 dPEG 4-SATA acid(S-acetyl-dPEG 4-acid)

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CAS: 1263044-79-6
Item Name: dPEG 4-SATA acid(S-acetyl-dPEG 4-acid)
Item #: 10180
Mol. Wt.: 324.39;
single compound dPEG Spacer is 16 atoms and 18.3 A
Product Features and Benefits: dPEG versions of the popular SATA reagent, providing a method for converting the amino group to a thiol with the incorporation of the pegylation unit This acid form needs to be activated in sita to some form of active ester. Adds the amazing properties of dPEG , including added pegylation spacer distance, a spacer that is highly hydrophilic, non-antigenic, non-immunogenic and non-toxic Greater accessibility of reaction/modification site: Spacer distance makes the amine, now thiol, much more accessible, e.g., a maleimide, vinyl sulfone or a ?-halo keto functionalize reaction partner. Protocols: Our experience suggests that using conditions similar to those used for SATA to remove the acetyl protecting group can be applied for the dPEG 4 SATA Protocol for in situ activation as the NHS ester: Use a 10-20% molar excess of EDC and NHS in dry methylene chloride (dried over 3A molecular sieves). Add a methylene chloride solution of the acid to the dry reagents under dry conditions. Stir for several hours or overnight, then evaporate the solvent and use. Can also treat reaction mixture with a small amount of silica gel to adsorb the excess EDC and the urea by-product, filter, then evaporate the solvent and use.
Note of caution: The NHS should be added with the EDC to prevent formation of the anhydride. DCC can also be used. Typically use about 1 equivalent, and add a solution of the DCC to the acid and NHS (1.1 to 1.2 equivalents). HOBt or PFP (2,3,4,5,6-pentafluorophenol) could be used in place of the NHS, if this is a preference for the activated ester. 158 too can be used as well, but these are probably the most popular. If one wanted to make the sulfo-NHS ester then one would need to use a much more polar solvent in order to accommodate the very poor solubility of the sulfo-NHS in organic solvents, using solvents such as DMF or DMAC.