Pectins as Biological Modulators of Human Physiological Reactions#

Pectins are complicated heteropolysaccharides belonging to the group of acidic plant polysaccharides, glycanogalacturonans (Ovodov 2009). Pectin is well known to be an important component of the primary cell wall and intercellular substance (middle lamella) of higher terrestrial plants, sea grasses and some freshwater algae (Popper 2008). The primary plant cell wall is composed of a mixture of cellulose, hemicellulose, and pectin, while the middle lamella can be considered as an extension of this matrix material from which the cellulose are lacking. Pectic substances make up about 30 percentage of the dry matter of the primary cell wall and are the primary macromolecules of the middle lamella. In the plant cell wall several dozen chains of cellulose interconnected by hydrogen and van der Waals forces form linear microfi bril. Molecules of hemicelluloses, which include xyloglucan, xylans, glucuronoarabonoxilans, gluco-, galacto-, and galactoglucomannans are situated between these microfi brils forming network with the molecules of cellulose (Burton et al. 2010). The entire network of cellulose microfi brils and linking them hemicelluloses is immersed in a matrix of pectic substances. It acts as the cementing agent for the fi brils, provides them with effective tensile and keeps the cell walls of adjacent cells glued together. Pectins contribute to the mechanical strength, porosity, adhesion and stiffness of the cell wall and have been implicated in many processes, including wall slippage, extension and intercellular signaling. In total, pectin functions in plants have been thoroughly investigated (Palin and Geitmann 2012, Wolf and Greiner 2012, Komarova et al. 2014, Yokawa and Baluska 2015).