Heparin functional group derivatization

To elucidate heparin anticoagulant effects caused by covalent coupling via specific functional groups, those heparin groups involved in immobilization reactions are first derivatized, and the effect of derivatization on anticoagulant activity is determined. 

This chapter focuses on the effects of anticoagulant activity caused by specific functional group derivatization of heparin, and on preliminary immobilization spacer group evaluations. The functional groups selected for immobilization are hydroxyl and carboxylic heparin groups. 

Functional Group Derivatization. Carboxylic Derivatization. Two grams of N -acetylated heparin and 2 mL of n-butylamine were dissolved in 40 mL of water, and the pH was adjusted to 4.75. A total of 0.8 g of l-ethyl-3-(3-dimethylaminopro-pyl)carbodiimide hydrochloride was added to the heparin/n-butylamine solution in approximately 10-mg portions over a 6-h period while the reaction was maintained at 4°C and pH 4.75. Periodic samples were withdrawn from the reaction vessel, dialyzed, and freeze-dried. In a separate reaction, 0.5 g of N-acetylated heparin and 1.0 g of 2-aminoethyl hydrogen sulfate were dissolved in 10 mL of water and adjusted to pH 4. 75. A total of 0.2 g of l-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride was added to the reaction vessel in approximately 10-mg portions over a 4-h... 

Covalent immobilization of chemically synthesized carbohydrates onto derivatized surfaces by Seeberger group, (a) Attachment of thiol containing carbohydrates to maleimide-functionalized glass slides (b) attachment of amine-terminated heparin oligosaccharides onto amine-reactive glass slides... 

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