Pectin isolated from white cabbage – structure and complement-fixing activity

Abstract

This study was done to investigate whether white cabbage contained polysaccharides with immunostimulatory activity using the complement-fixing test as an indicator. The main polysaccharide isolated was of pectin nature. Methanolysis and (13)C-NMR showed that the polymers consisted of highly esterified alpha-galactopyranoside (alpha-GalpA), significant amounts of alpha-arabinose furanoside (alpha-Araf), beta-Galp and lesser amounts of rhamnose in the pyranose form (Rhap) and xylose in the pyranose form (Xylp). Linkage analyses showed that the alpha-GalpA residues were mainly 1,4-linked with small amounts of 1,3,4-linkages. The alpha-Araf residues were mainly terminally (t)- and 1,5-linked, whereas beta-Galp was t-, 1,3-, 1,6-, and 1,3,6-linked. Positive Yariv reaction indicated polymers with arabinogalactan type 2 like structures. alpha-Rhap was mainly present as 1,2- and 1,2,4-linked residues and Xylp was t- and 1,4-linked. The molecular weight varied greatly and was from 10 to 150 kDa. Cabbage polymers had biological activity and this complement-fixing activity was greatly affected by hydrolytic removal of Araf from pectic side chains.

Structural analysis of an innate immunostimulant from broccoli, <i>Brassica oleracea</i> var. <i>italica </i>

“…Detection of the 2,4-Rhap residue suggests that the AF has an RG-I structure; i.e. →4)-α-GalpA-(1→2)-α-Rhap-(1→, with the Rha residue substituted for by galactan and arabinan chains at the C-4 position (14,17). The presence of T-Araf, 3-Araf, and 3,5-Araf residues suggest that the α-1,5-arabinan chains are partially branched at the C-3 position (14,17).…”

“…→4)-α-GalpA-(1→2)-α-Rhap-(1→, with the Rha residue substituted for by galactan and arabinan chains at the C-4 position (14,17). The presence of T-Araf, 3-Araf, and 3,5-Araf residues suggest that the α-1,5-arabinan chains are partially branched at the C-3 position (14,17). Detection of T-Galp, 4-Galp, 3-Galp, 6-Galp, and 3,6-Galp suggest the presence of β-1,4-galactan and β-1,3/6-galactan structures in the AF (14,17).…”

“…The presence of T-Araf, 3-Araf, and 3,5-Araf residues suggest that the α-1,5-arabinan chains are partially branched at the C-3 position (14,17). Detection of T-Galp, 4-Galp, 3-Galp, 6-Galp, and 3,6-Galp suggest the presence of β-1,4-galactan and β-1,3/6-galactan structures in the AF (14,17). We cannot propose the binding sites of the T-Rhap and T-Glcp residues detected as a minor components based on the methylation analysis.…”

Characterization of a pectic polysaccharide from the leaves of Diospyros kaki and its modulating activity on lymphocyte proliferation

“…Pectins are widely used as textural food ingredients, gelling, and thickening agents or dairy products, largely because of their galacturonic acid (GalA)‐rich regions. In the recent years, a number of bioactive pectins have been extensively investigated through chemical analysis and enzymic degradation, and these bioactivities are believed to be mainly linked to their complex side chains 5–12…”

Release and characterization of single side chains of white cabbage pectin and their complement‐fixing activity

“…Samples were prepared according to Westereng et al [29]. 13 C-NMR spectra were recorded on a Varian 300 MHz instrument (spectrometer frequency 75.44 MHz) at 408C applying 2 s pulse delay, 1.64 s acquisition time, 858 pulse angle, a sweep width of 15 974 Hz, and collection of approximately 60 000 data points.…”