title: Glycosylation of genistin into soluble inclusion complex form of cyclic glucans by enzymatic modification.
abstract: The enzymatic modification of genistin to enhance its water solubility was studied using two glycosyltransferases, cyclodextrin glucanotransferase from alkalophilic Bacillus sp. I-5 and 4-alpha-glucanotransferase from Thermus scotoductus. Two different catalytic reactions, the transglycosylation and cyclization activities, were observed when the reaction was performed with soluble starch as a donor and genistin as an acceptor. The reaction products were isolated and identified as [Glc(alpha1-4)](1-22)-Glc(beta1-7)-genisteins and cycloamylose with DP 8-12 by HPLC and MALDI-TOF MS. A beta-amylase treatment revealed inclusion complexes composed of Glc(alpha1-4)-Glc(beta1-7)-genistein/Glc(alpha1-4)-Glc(alpha1-4)-Glc(beta1-7)-genistein and cycloamylose with DP 8-12. The results indicated that the cycloamylose formed by the cyclization reaction of the enzyme included Glc(alpha1-4)-Glc(beta1-7)-genistein/Glc(alpha1-4)-Glc(alpha1-4)-Glc(beta1-7)-genistein. The presence of cycloamylopectin, in which the Glc(alpha1-4)-Glc(beta1-7)-genistein/Glc(alpha1-4)-Glc(alpha1-4)-Glc(beta1-7)-genistein was enclosed, was also observed with HPLC, HPSEC-MALLS, and MALDI-TOF MS analyses. The solubility of genistin was highly improved, and the solution containing glycosylated genistin and the inclusion complex demonstrated excellent properties of transparency and stability during storage at 4 degrees C.
authors.affiliation: Center for Agricultural Biomaterials, School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Korea.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Sun-Ah
authors.initials: SA
authors.lastname: Roh
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Shim
authors.forename: Bunzo
authors.initials: B
authors.lastname: Mikami
authors.forename: Moo-Yeol
authors.initials: MY
authors.lastname: Baik
authors.forename: Cheon-Seok
authors.initials: CS
authors.lastname: Park
authors.forename: Kwan-Hwa
authors.initials: KH
authors.lastname: Park
mesh_terms: D001407:Bacillus / Q000201:enzymology; D019833:Genistein / Q000378:metabolism*; D005936:Glucans / Q000378:metabolism*; D005964:Glucosyltransferases / Q000378:metabolism; D006004:Glycogen Debranching Enzyme System / Q000378:metabolism; D006031:Glycosylation; D015394:Molecular Structure; D012995:Solubility; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013213:Starch / Q000378:metabolism; D013824:Thermus / Q000201:enzymology
chemical_list: D005936:Glucans; D006004:Glycogen Debranching Enzyme System; D013213:Starch; D019833:Genistein; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase; C020569:4 alpha-glucanotransferase