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2.2.2.3 Mannans
ОглавлениеMannans have further two types. 1) Glucomannans which is an important hemicellulose that are abundantly found in the secondary cell wall of the gymnosperms and minorly in the secondary cell wall of angiosperms. Structurally, it consists of (1–4) β-linked mannose in the case of mannan while the glucose and mannose in non-repeating pattern in the case of glucomannans. In the angiosperms, a single galactose residue has been attached to the backbone of glucomannans that often known as galactoglucomannans. Functionally, glucomannans act as storage polysaccharides in the endosperm cell wall of many angiosperms. During the germination the seed-derived hydrolytic enzymes such as, beta-endomannanase, beta-endoglucanase, and alpha-galactosidase help in the deployment of glucomannan that also known as storage polysaccharides [13, 19]. 2) Glucuronomannans that primarily been found in the cell wall in very trace amount. They consist of α (1–4) linked D-mannose subunits with alternative (1–2) β-linked glucuronic acid residues. In branched side chain the arabinose and β-galactose have bonded to mannose via (1–6) and (1–3) linkages [13].