3-deoxy- d- manno-2-octulosonic acid (KDO) is a component of rhamnogalacturonan II, a pectic polysaccharide in the primary cell walls of plants

Abstract

3-Deoxy- d- manno-2-octulosonic acid (KDO), a sugar previously presumed to occur only as a glycosyl residue in polysaccharides produced by Gram-negative bacteria, was found to be a component of the cell walls of higher plants. In the form of the disaccharide α- l-Rha p-(1→5)- d-KDO, KDO was released by mild hydrolysis with acid from the purified cell wall polysaccharide rhamnogalacturonan II. KDO was shown to be present in purified cell walls of several plants, including dicots, a monocot, and a gymnosperm. Improved methods for detecting and quantitating KDO residues in polysaccharides were developed during this investigation.