Studies on the cationization of agarose

HÉCTOR J. PRADO; MARÍA C. MATULEWICZ; PABLO R. BONELLI; ANA L. CUKIERMAN

CARBOHYDRATE RESEARCH

ELSEVIER SCI LTD

Lugar: Oxford, Gran Bretaña; Año: 2010

0008-6215

Cationized agaroses with different degrees of substitution (0.04–0.77) were synthesized,employing 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC). Theinfluence of different reaction parameters on the substitution degree and molecularweight was evaluated. The investigated parameters were concentration of reagents,temperature, time and addition of NaBH4. The products were characterized by means ofscanning electronic microscopy, infrared spectroscopy, viscosimetry and NMRspectroscopy. Methanolysis products were studied by electrospray ionization massspectrometry. The higher the concentration of CHPTAC employed, a higher degree ofsubstitution was obtained, if the optimum concentration of NaOH in each case wasemployed. Insufficient quantities of NaOH reduced epoxide formation and the reactingalkoxides of the polysaccharide, whereas an excess of NaOH favored degradation of theepoxide and decrease in the molecular weight of the product. A reaction time of 2 hwas sufficient to obtain products with the maximum degree of substitution for eachcase. The addition of NaBH4 gave products with a slightly higher molecular weight, butthe extra cost involved should not justify its use for large-scale application.