Main content area

Functional New Acylated Sophoroses and Deglucosylated Anthocyanins in a Fermented Red Vinegar

Terahara, Norihiko, Matsui, Toshiro, Minoda, Kanako, Nasu, Kanae, Kikuchi, Risa, Fukui, Keiichi, Ono, Hiroshi, Matsumoto, Kiyoshi
Journal of agricultural and food chemistry 2009 v.57 no.18 pp. 8331–8338
functional properties, acylation, polyphenols, fermented foods, vinegars, food analysis, food composition
The new acylated polyphenols were isolated from a red-colored vinegar produced via fermentation with purple-fleshed sweet potato storage roots, and identified mainly by MS and NMR. The three acylated sophoroses were determined as 6-O-(E)-caffeoyl-(2-O-(6-O-acyl)-β-d-glucopyranosyl)-d-glucopyranoses, where acyl was (E)-caffeoyl, p-hydroxybenzoyl, and (E)-feruloyl, respectively. The four acylated anthocyanins were also determined as cyanidin 3-O-(6-O-(E)-caffeoyl-(2-O-(6-O-(E)-feruloyl)-β-d-glucopyranosyl)-β-d-glucopyranoside), in addition to peonidin 3-O-(6-O-(E)-caffeoyl-(2-O-(6-O-acyl)-β-d-glucopyranosyl)-β-d-glucopyranosides), where acyl was (E)-caffeoyl, p-hydroxybenzoyl, and (E)-feruloyl, respectively. The diacylated sophoroses showed higher antioxidant capacity than that of monoacylated analogue 6-caffeoylsophorose, so the multiacylation established to enhance their antioxidant capacity. Similarly, 5-deglucosylated anthocyanins also gave somewhat stronger antioxidation than corresponding sweet potato anthocyanins. In rat intestinal α-glucosidase inhibition study, the diacylated sophoroses preferably inhibited maltase rather than sucrase with an IC50 value of <300 μM, indicating a potential role as antidiabetic phytochemicals. These acylated polyphenols in a red vinegar were expected to play important functional roles for health.