Synthesis of xylooligosaccharides of daidzein and their anti-oxidant and anti-allergic activities.

ABSTRACT

The biocatalytic synthesis of xylooligosaccharides of daidzein was investigated using cultured cells of Catharanthus roseus and Aspergillus sp. ß-xylosidase. The cultured cells of C. roseus converted daidzein into its 4'-O-ß-glucoside, 7-O-ß-glucoside, and 7-O-ß-primeveroside, which was a new compound. The 7-O-ß-primeveroside of daidzein was further xylosylated by Aspergillus sp. ß-xylosidase to daidzein trisaccharide, i.e., 7-O-[6-O-(4-O-(ß-d-xylopyranosyl))-ß-d-xylopyranosyl]-ß-d-glucopyranoside, which was a new compound. The 4'-O-ß-glucoside, 7-O-ß-glucoside, and 7-O-ß-primeveroside of daidzein exerted DPPH free-radical scavenging and superoxide radical scavenging activity. On the other hand, 7-O-ß-glucoside and 7-O-ß-primeveroside of daidzein showed inhibitory effects on IgE antibody production.