Studies on the cationization of agarose

Cationized agaroses with different degrees of substitution (0.04–0.77) were synthesized, employing 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC). The influence of different reaction parameters on the substitution degree and molecular weight was evaluated. The investigated parameters were concentration of reagents, temperature, time, and addition of NaBH4. The products were characterized by means of scanning electronic microscopy, infrared spectroscopy, viscosimetry, and NMR spectroscopy. Methanolysis products were studied by electrospray ionization mass spectrometry. The higher the concentration of CHPTAC employed, a higher degree of substitution was obtained, if the optimum concentration of NaOH in each case was employed. Insufficient quantities of NaOH reduced epoxide formation and the reacting alkoxides of the polysaccharide, whereas an excess of NaOH favored degradation of the epoxide and decrease in the molecular weight of the product. A reaction time of 2 h was sufficient to obtain products with the maximum degree of substitution for each case. The addition of NaBH4 gave products with a slightly higher molecular weight, but the extra cost involved should not justify its use for large-scale application. Fil: Prado, Héctor Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones En Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones En Hidratos de Carbono; Argentina Fil: Matulewicz, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones En Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones En Hidratos de Carbono; Argentina Fil: Bonelli, Pablo Ricardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cukierman, Ana Lea. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina