Synthesis and structural characterization of raffinosyl-oligofructosides upon transfructosylation by Lactobacillus gasseri DSM 20604 inulosucrase

摘要: A new process based on enzymatic synthesis of a series raffinose-derived oligosaccharides or raffinosyl-oligofructosides (RFOS) with degree polymerization (DP) from 4 to 8 was developed in the presence raffinose. This involves transfructosylation reaction catalyzed by an inulosucrase Lactobacillus gasseri DSM 20604 (IS). The main synthesized RFOS were structurally characterized nuclear magnetic resonance (NMR). According elucidated structures, consist β-2,1-linked fructose unit(s) raffinose: α-d-galactopyranosyl-(1 → 6)-α-d-glucopyranosyl-(1↔2)-β-d-fructofuranosyl-((1 ← 2)-β-d-fructofuranoside)n (where n refers number transferred moieties). maximum yield 33.4 % (in weight respect initial amount raffinose) and obtained at time interval 8–24 h initiated 50 % (w/v) Results revealed high acceptor donor affinity IS towards raffinose, being fairly comparable that sucrose for production fructooligosaccharides (FOS), including when both carbohydrates coexisted (sucrose/raffinose mixture, 250 g L−1 each). also attempted sucrose/melibiose mixtures; this case, predominant acceptor-product formed raffinose followed minor varying DP. easiness structural similarities fructan warrant further study potential bioactive properties these unexplored oligosaccharides.