Ascorbic acid, also known as vitamin C, is an effective antioxidant and an essential human enzymatic cofactor. However, it is unstable when isolated in aqueous solutions and readily degrades upon exposure to air and ultraviolet light. PAMAM (polyamidoamine) dendrimers were evaluated to stabilize dilute aqueous solutions of ascorbic acid. UV-Vis absorbance spectroscopy was used to measure the degradation and stabilization over four hours with various dendrimers and varying pH values. Our data shows that PAMAM dendrimers can significantly decrease the rate of degradation, especially near physiological pH. These results demonstrate dendrimers as a technology for stabilizing reactive organic molecules.
Available at: http://works.bepress.com/david_nowack/6/