Isolation of oligogalacturonic acids up to DP 20 by preparative high-performance anion-exchange chromatography and pulsed amperometric detection

Milligram quantities of oligogalacturonic acids up to a degree of polymeriz ation (DP) of 20 were purified by high-performance anion-exchange chromatog raphy utilizing a preparative-scale (21-mm i.d.) CarboPac PA1 column and a nonlinear potassium acetate (pH 7.5) gradient. Detection was accomplished b y pulsed amperometry without post-column addition of hydroxide. Pulsed ampe rometry at near-neutral pH is an excellent detection method for preparative separations of carbohydrates because it avoids base-catalyzed degradation reactions that can occur at high pH. This method was simpler. faster, had h igher sample loading capacity and allowed for the isolation of higher DP ol igogalacturonic acids than other methods reported previously. With this imp roved method, multi-milligram quantities of valuable oligogalacturonic acid s (up to DP 20) can be readily isolated. (C) 2001 Elsevier Science Ltd. All rights reserved.