title: Glucosylation of flavonol and flavanones by Bacillus cyclodextrin glucosyltransferase to enhance their solubility and stability.
abstract: 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 Cu2+ion was strongly increased by the oligoglucosylation. This is probably because oligoglucosylation may protect sensitive parts of an aglycones molecule from the Cu2+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.
authors.affiliation: Research Institute of Food and Nutritional Sciences and Department of Food and Nutrition, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Young-Su
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Research Institute of Food and Nutritional Sciences and Department of Food and Nutrition, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Jang-Bin
authors.initials: JB
authors.lastname: Woo
authors.affiliation: Research Institute of Food and Nutritional Sciences and Department of Food and Nutrition, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Soo-In
authors.initials: SI
authors.lastname: Ryu
authors.affiliation: Department of Food and Nutrition, Chung-Ang University, Ansung 456-756, Republic of Korea.
authors.forename: Seong-Kwon
authors.initials: SK
authors.lastname: Moon
authors.affiliation: Department of Food Science and Technology, Chungbuk National University, Chungju, Chungbuk 361-763, Republic of Korea.
authors.forename: Nam Soo
authors.initials: NS
authors.lastname: Han
authors.affiliation: Research Institute of Food and Nutritional Sciences and Department of Food and Nutrition, Yonsei University, Seoul 120-749, Republic of Korea. Electronic address: soobok@yonsei.ac.kr.
authors.forename: Soo-Bok
authors.initials: SB
authors.lastname: Lee
mesh_terms: D001407:Bacillus / Q000737:chemistry*; D003505:Cyclodextrins / Q000737:chemistry*; D044950:Flavanones / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D012995:Solubility
chemical_list: D003505:Cyclodextrins; D044950:Flavanones; D005419:Flavonoids; C041477:3-hydroxyflavone
keywords: Bacillus macerans; Cyclodextrin glucosyltransferase; Flavanone; Flavonol; Glucosylation; Solubility