Journal of agricultural and food chemistry 2017 03 16() doi 10.1021/acs.jafc.7b00501
Kaempferol-3-O-β-D-glucopyranoside (astragalin, AS), a major flavonoid that exists in various plants, exerts anti-oxidant, anti-tumor, anti-human immunodeficiency virus (HIV), and anti-inflammatory effects. However, the low water solubility of AS limits its use. In this study, we used cyclodextrin glucanotransferase (CGTase) with maltose (G2) as a donor molecule to enzymatically modify AS to improve its water solubility and physiochemical properties. We isolated the glycosylated astragalin (G1-AS) and identified the structure of G1-AS as kaempferol-3-O-β-D-glucopyranosyl-(1→4)-O-α-D-glucopyranoside, where one glucose residue was transferred to AS. G1-AS retained the anti-oxidative activity of the original AS compound; however, the solubility of G1-AS was 65-fold higher than that of AS. In addition, G1-AS showed enhanced anti-inflammatory effects and aldose reductase inhibitory activity compared to AS when applied to rat lenses.