Artichoke pectic oligosaccharide characterisation and virtual screening of prebiotic properties using in silico colonic fermentation

The aim of this work was to develop a comprehensive workflow to elucidate molecular features of artichoke pectic oligosaccharides (POS) contributing to high potential prebiotic activity. First, obtainment of artichoke POS by Pectinex (R) Ultra-Olio was optimised using an artificial neural network. Under optimal conditions (pH 6.86; 1.5 h; enzyme dose 520.5 U/g pectin) POS yield was 624 mg/g pectin. Oligosaccharide structures (M-w < 1.3 kDa) were characterised by MALDI-TOF-MS. Then, conformational analysis of glycosidic bonds was performed by replica exchange molecular dynamics simulations and interaction mechanisms between POS and several microbial glycosidases were proposed by molecular modelling. Chemical information was integrated in virtual simulations of colonic fermentation. Highest hydrolysis rate was obtained for Ga1A-Rha-Ga1A trisaccharide, while the presence of partial negative charges and high radius of gyration enhance short chain fatty acid formation in distal colon. Established structure-activity relationships could help the rational design of prebiotics and clinical trials.

Automated summary

This study aimed to develop a comprehensive workflow to elucidate molecular features of artichoke pectic oligosaccharides (POS) contributing to high potential prebiotic activity. By optimizing the obtainment of artichoke POS and characterizing the oligosaccharide structures, the study proposed interaction mechanisms between POS and microbial glycosidases, as well as integrated chemical information in virtual simulations of colonic fermentation. The established structure-activity relationships could potentially help in the rational design of prebiotics and in clinical trials.