Research Institute of Food and Nutritional Sciences and Department of Food and Nutrition, Yonsei University, Seoul 120-749, Republic of Korea.
Department of Food and Nutrition, Chung-Ang University, Ansung 456-756, Republic of Korea.
Food Chem. 2017 Aug 15;229:75-83. doi: 10.1016/j.foodchem.2017.02.057. Epub 2017 Feb 16.
Enzymatically modified isoquercitrin (EMIQ), oligoglucosyl naringenin-7-(glucose [G]), and oligoglucosyl hesperetin (H)-7-G were produced via oligoglucosylation of quercetin-3-glucose, naringenin-7-G (prunin), and H-7-G, respectively, by cyclodextrin glucosyltransferase from Bacillus macerans. The aim was to explore the oligoglucosylation and the resulting changes in physicochemical properties. Water solubility of EMIQ, oligoglucosyl prunin, and oligoglucosyl H-7-G enormously increased in comparison with that of their aglycones. Glycosylation of an aglycone generally enhances its solubility. Resistance of the aglycones to oxidative degradation by the Cu ion was strongly increased by the oligoglucosylation. This is probably because oligoglucosylation may protect sensitive parts of an aglycones molecule from the Cu oxidation. Only EMIQ maintained its structure during thermal treatment much longer than quercetin did. Degradation of flavonoid aglycones by ultraviolet light C irradiation at 254nm was not affected, and their antioxidant activities gradually decreased with the greater extent of oligoglucosylation.
酶法改性异槲皮苷（EMIQ）、低聚葡萄糖基柚皮素-7-葡萄糖（G）和低聚葡萄糖基橙皮素-7-G 分别通过大麦芽环糊精葡萄糖基转移酶对槲皮素-3-葡萄糖、柚皮素-7-G（橙皮苷）和 H-7-G 的寡糖基化产生。目的是探索寡糖基化及其理化性质的变化。与母体化合物相比，EMIQ、低聚葡萄糖基橙皮苷和低聚葡萄糖基橙皮素-7-G 的水溶性大大增加。糖苷化通常会增加母体化合物的水溶性。寡糖基化强烈提高了母体化合物对铜离子氧化降解的抗性。这可能是因为寡糖基化可以保护母体化合物分子中敏感部位免受铜氧化。只有 EMIQ 在热疗过程中保持其结构的时间远远长于槲皮素。254nm 紫外线 C 辐射对类黄酮母体化合物的降解没有影响，其抗氧化活性随着寡糖基化程度的增加逐渐降低。
