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Activation and Conjugation of Soluble Polysaccharides using 1-Cyano-4-Dimethylaminopyridine Tetrafluoroborate (CDAP)
Published on: June 14, 2021
Stability studies of hydrazide and hydroxylamine-based glycoconjugates in aqueous solution
Anna V Gudmundsdottir1, Caroline E Paul, Mark Nitz
1Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, Canada.
Carbohydrate Research
|December 6, 2008
Summary
Researchers explored optimal conditions for creating stable glycoconjugates using various sugars and nucleophiles. They found conjugate stability increases with pH, similar to O-glycoside hydrolysis patterns.
Area of Science:
- Carbohydrate Chemistry
- Bioconjugation Chemistry
Background:
- Glycoconjugates are formed via condensation reactions.
- Understanding their formation and stability is crucial for applications.
Purpose of the Study:
- To investigate optimal conditions for glycoconjugate formation.
- To characterize the stability of various glycoconjugates.
- To determine hydrolysis rates and half-lives.
Main Methods:
- Condensation reactions using monosaccharides (xylose, glucose, N-acetylglucosamine) and nucleophiles (p-toluenesulfonyl hydrazide, N-methylhydroxylamine).
- Determination of apparent association constants at pH 4.5.
- Measurement of hydrolysis rate constants at pH 4.0, 5.0, and 6.0 at 37°C.
Main Results:
- Apparent association constants ranged from 9-74 M(-1) at pH 4.5.
- Half-lives of the glycoconjugates varied significantly, from 3 hours to 300 days.
- Conjugate stability increased as the pH approached neutrality.
- Hydrolysis rates correlated with O-glycoside hydrolysis, with electron-rich monosaccharides yielding faster hydrolysis.
Conclusions:
- Optimal conditions for glycoconjugate formation and stability were elucidated.
- Glycoconjugate stability is pH-dependent, increasing towards neutral pH.
- The study provides insights into the factors influencing glycoconjugate stability and hydrolysis.
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