Short-chain β-manno-oligosaccharides from copra meal: structural characterization, prebiotic potential and anti-glycation activity

Size-exclusion chromatography, HR-ESI-MS and FT-IR of copra meal hydrolyzed by ManB-1601 showed the presence of oligosaccharides (CM-beta-MOS) having a degree of polymerisation (DP) between 2 and 4. Thermal decomposition studies of the purified CM-beta-MOS (DP 2, 3 and 4) showed mass loss at high temperatures (135.8 degrees C to 600 degrees C). DP2, DP3 and DP4 CM-beta-MOS were adjudged as un-substituted Man beta-4Man, Man beta-4Man beta-4Man and Man beta-4Man beta-4Man beta-4Man, respectively, using NMR (H-1 and C-13) studies. During fermentation, purified CM-beta-MOS supported the growth of Lactobacillus sp. and inhibited enteropathogens (Escherichia coli, Listeria monocytogenes and Salmonella typhi). Acetate was the predominant short-chain fatty acid produced by Lactobacillus sp. RT-PCR studies of L. plantarum WCFS1 fed with CM-beta-MOS showed up-regulation (up to 6.7-fold) of the cellobiose utilization operon (pts23C and pbg6) and oligo-sucrose utilization loci (pts1BCA and agl2). Biochemical (free amino groups, carbonyl and fructosamine content), fluorescence (AGEs-specific and intrinsic) and molecular docking studies suggested the anti-glycation potential of CM-beta-MOS.

Automated summary

Size-exclusion chromatography, HR-ESI-MS, and FT-IR analysis revealed the presence of oligosaccharides (CM-beta-MOS) with a degree of polymerisation (DP) between 2 and 4 in hydrolyzed copra meal by ManB-1601. Thermal decomposition studies showed mass loss at high temperatures for purified CM-beta-MOS (DP 2, 3, and 4). NMR studies confirmed the chemical structure of CM-beta-MOS. During fermentation, purified CM-beta-MOS supported the growth of Lactobacillus sp. and inhibited enteropathogens. RT-PCR studies suggested up-regulation of specific genes in Lactobacillus sp. fed with CM-beta-MOS. Biochemical, fluorescence, and molecular docking studies indicated the potential anti-glycation effects of CM-beta-MOS.