Molecular dimensions and structural features of neutral polysaccharides from the seed mucilage of Hyptis suaveolens L. (15th April 2017)

• Record Type: Journal Article
• Authors: Praznik, Werner; Čavarkapa, Andrea; Unger, Frank M.; Loeppert, Renate; Holzer, Wolfgang; Viernstein, Helmut; Mueller, Monika
• Is Part Of: Food chemistry. Volume 221(2017)
• Page Start: 1997
• Page End: 2004
• Publication Date: 2017-04-15
• Subjects: Hyptis suaveolens L. -- Mucilage -- Polysaccharide -- Galactoglucan -- Galactoglucomannan -- Methylation analysis -- NMR spectroscopy; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2016.11.087
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: The neutral polysaccharides are composed of galactoglucan and galactoglucomannan. Both heteropolysaccharides possess a high level of terminal β-linkedd -Gal p residues. The galactoglucomannan includes octa, nona- and tetrasaccharide as repeating units. The main structural feature is the β-d -Glc p -(1 → 4)[β-d -Gal p -(1 → 2)-α-d -Gal p -(1 → 6)]-d -Man p unit. The prebiotic activity is related to the terminal β-linkedd -Gal p residues. Abstract: The seed mucilage of Hyptis suaveolens L. includes acid – and neutral heteropolysaccharides in a ratio of about 1:1. The anionic charged fraction responsible for swelling and viscous behaviour possesses an average molar mass of Mw = 350 kg/mol, Mn = 255 kg/mol. The neutral polysaccharide fraction shows an average molar mass of Mw = 47 kg/mol and Mn = 28 kg/mol and is composed ofd -Gal p-, d -Glc p- andd -Man p residues in a molar ratio of about 3:2:1. The structural features present galactoglucan (30%) and galactoglucomannan (70%) with a high level of terminal β-linkedd -Gal p residues (18%). Structural details of galactoglucomannan are derived by combined enzymatic and chemical methods as well as NMR spectroscopy. Sequences of octa/nonasaccharide β-d -Glc p -(1 → 4)[β-d -Gal p -(1 → 2)-α-d -Gal p -(1 → 6)]-β-d -Man p -(1 → 4)-β-d -Glc p -(1 → 4)-β-d -Glc p -(1 → 4)[β-d -Gal p -(1 → 2)-α-d -Gal p -(1 → 6)]-β-d -Man p and lower mass tetrasaccharide repeating units β-d -Glc p -(1 → 4)[β-d -Gal p -(1 → 2)-α-d -Gal p -(1 → 6)]-β-d -Man p were found. The level of the prebiotic activity is related to the availability of β-linkedd -Gal p residues in the side chains of the molecules.