The immunologically active xylan from ultrasound-treated corn cobs:: extractability, structure and properties

The extractability of the corn cob xylan, particularly its water-soluble component (ws-X), was studied using extraction methods with and without application of ultrasound in water and aqueous NaOH. The results indicate that ws-X comprise a variety of xylan polymers differing in the proportion of side chains composed of single arabinose and glucuronic acid side chains and 2-O-beta-D-xylopyranosyl-alpha-1-arabinofuranose moieties. The xylan fractions were characterized by yield, composition, structural features, molecular properties and biological response in mitogenic and comitogenic thymocyte tests. Compared to the classically extracted xylans, the ws-X prepared by the assistance of ultrasound had the same primary structure features and similar or slightly higher stimulatory activities in both tests. (C) 1998 Elsevier Science Ltd. All rights reserved.