Submitted to: New Orleans Carbohydrate Symposium
Publication Type: Abstract Only
Publication Acceptance Date: April 4, 1998
Publication Date: N/A
Technical Abstract: The advantages of studying dendritic macromolecules and comparing them with polysaccharides are many-fold. Liquid chromatographic determinations may assist in placing a practical limit on the solution-phase behavior of carbohydrates as dendritic branching constitutes the highest form of branching achievable. The study of small, low-molecular weight dendrimers can be constrasted with results of studies of the large variety of plant saccharides coexisting at the early stages of substrate development or with the products of enzymatic and/or hydrolytic degradations. Additionally, the high degree of branching present in dendrimers may provide a reasonable model for extremely highly branched plant polymers such as amylopectin and arabinogalactan. The experiments presented herein detail the comparison of several dendrimers, belonging to two classes with different functionalities with low molecular weight (< 70,000 Da) dextrans and with various malto- dextrins. Size exclusion chromatography (SEC) has been used to determine molecular weight averages, distributions, and polydispersities, and to contrast the intrinsic viscosity distributions of linear polysaccharides to those of dendrimers with equivalent molecular weights. Where SEC was unable to determine molecular weight averages and distributions due to low solubility of certain dendrimers, mass spectrometric characterization was conducted. In addition, computer modeling of the dendrimers allowed comparison of their calculated size in solution to previously published literature values, while also showing the narrow distribution the radii of gyration possess.