Polysaccharides pectic

The variation ia water solubiUty among polysaccharides results ia varied physiological roles. Plant ceU-waH polysaccharides and lignin provide iasoluble dietary fiber (IDF) nondigestible storage polysaccharides, some pectic polysaccharides, and most of the functional additives contribute soluble dietary fiber (SDF). 

Bioactive Pectic Polysaccharides Isolated from Plants. 77... 

Figure 6 from Carbohydrate Research, vol 311, Sakurai MH, Kiyohara H, Matsumoto T, TsumurayaY, Hashimoto Y, Yamada H (1998) Characterization of antigenic epitopes in anti-ulcer pectic polysaccharides from Bupleurum falcatum L. using several carbohy-drases. p 219-p229, all with permission from Elsevier... 

Kacurakova, M., Capek, P., Sasinkova, V., WeUner, N. Ebringerova, A. (2000). FT-IR study of plant cell wall model compounds pectic polysaccharides and hemicelluloses. Carbohydrate Polymers, Vol. 43,2, (October 2000), pp. (195-203), ISSN 0144-8617... 

Bishop et al. (1984) have isolated a pectic polysaccharide (6 kDa) from tomato leaves that can elicit the induction of proteinase inhibitors. Upon further hydrolysis this pectic polysaccharide yields oligogalacturanan (degree of polymerisation from 2 to 6) that still possesses the proteinase inhibitor inducing activities. 

Rhamnogalacturonan 11 (RG-11) is a structurally complex, pectic polysaccharide that is present in the primary cell-walls of higher plants. It is composed of 60 glycosyl residues, and is a very complex molecule indeed. For example, on acid hydrolysis, at least ten different monosaccharides are formed, including the novel aceric acid (30), which is the only branched-... 

The pectin network.-The second polysaccharide network present in primary cell walls is composed of pectic polysaccharides. The pectin network appears to coexist with the cellulose/hemicellulose network, that is, both networks appear to be able to share the same space [16-19]. However, the proportions of the two networks appear to vary from location to location within a single cell wall as well as from the primary wall of one type of cell to the primary wall of a another type of cell [9,20-22]. 

There are three pectic polysaccharides in all primary cell walls that have been studied these are rhamnogalacturonan n, rhamnogalacturonan I, and homogalacturonan. 

The pectin network revisited.--The importance of the interconnections of the pectic polysaccharides to the integrity of the pectin network has been highlighted by the recent discovery that RG-II is present in primary walls as a mixture of monomers and dimers [54]. The dimers are covalently cross-linked by borate diesters [55,56]. If single molecules of homogalacturonan are covalently attached to both RG-I and RG-II, the covalently cross-linked RG-n dimers would explain how the network of the three types of pectic polysaccharides is covalently connected and covalently cross-linked. 

The Pectic Polysaccharide Rhamnogalacturonan II is a major Component of the Polysaccharides present in Fruit-derived Products. 

The polysaccharide composition and structure of pectic polysaccharides present in fruit-derived products have been the aim of numerous studies [14-19]. However, the attention of scientists was focused on the analysis of rhamnogalacturonan I or so-called pectic hairy regions. As far as we know, the presence of RG-II in fruit juices has not been reported. 

Fruit-derived products used as source of pectic polysaccharides... 

Cell free synthesis of the pectic polysaccharide homogalacturonan... 

The primary walls of growing plant cells are composed of 90% carbohydrate and 10% protein (51). Carbohydrate in the primary wall is present predominantly as cellulose, hemicellulose, and pectin. The pectic polysaccharides, are defined as a group of cell wall polymers containing a-l,4-linked D-galactosyluronic acid residues (62,76). Pectic polysaccharides are a major component of the primary cell waU of dicots (22-35%), arc abundant in gymnosperms and non-graminaceous monocots, and are present in reduced amounts (-10%) in the primary walls of the graminaceae (27,62). 

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