关键词: 槲皮素, 糖基转移酶, 槲皮素糖苷, 水溶性, RAW264.7, 抗炎

Abstract: Glycosylation of quercetin was carried out using microbial-derived glycosyltransferases GT-1, GT-2 and BTGT-1. It was found that the three enzymes can catalyze the production of quercetin-3-O-glucose (isoquercitrin) with quercetin and UDP-glucose as substrate. The product formation rates of GT-1,GT-2 and BTGT-1 catalytic reactions were 5.33%, 15.18% and 63.82%, respectively. The water-soluble and anti-inflammatory activity of quercetin, quercetin-3-O-glucose and quercetin-N-acetyl-D-glucosamine in vitro were tested. It was found that the water solubility of isoquercitrin and quercetin-N-acetyl-D-glucosamine was 13.8 times and 15.4 times higher than that of quercetin, respectively, clearly suggesting that glycosylation can greatly improve water solubility of quercetin. The toxic effect of quercetin glycoside on RAW264.7 cells was lower than that of quercetin at the same concentration, but the three compounds showed significant effects on the release of NO, IL-1β and IL-6 in LPS-induced RAW264.7 cells in a dose-dependent manner, which futher displayed that they have a certain anti-inflammation potential.

Key words: quercetin, glycosyltransferase, quercetin glycoside, water solubility, RAW264.7, anti-inflammatory