T. Nishimura et al., GLUCOSYLATION OF CAFFEIC ACID WITH BACILLUS-SUBTILIS X-23 ALPHA-AMYLASE AND A DESCRIPTION OF THE GLUCOSIDES, Journal of fermentation and bioengineering, 80(1), 1995, pp. 18-23
Caffeic acid was glucosylated with hydroquinone glucosylating enzyme (
HGE) from Bacillus subtilis X-23 in order to improve its characteristi
cs. Caffeic acid glucosides were found to be produced effectively from
maltopentaose and caffeic acid in 30% ethanol solution. The glucoside
s were isolated from the reaction mixture by successive chromatography
on DIAION HP-20, Sephadex G-10, and octadecyl sililated silica gel, f
ollowing which two kinds of glucosides were obtained. The structures o
f these glucosides were confirmed to be caffeic acid 3-O-alpha-glucopy
ranoside and caffeic acid 4-O-alpha-glucopyranoside by H-1-NMR and C-1
3-NMR. The solubility of caffeic acid in water was increased by glucos
ylation without the loss of any biological activity, such as its antio
xidative and antimutagenic properties.