title: Different molecular complexity of linear-isomaltomegalosaccharides and β-cyclodextrin on enhancing solubility of azo dye ethyl red: towards dye biodegradation.
abstract: Intermolecular interaction of linear-type α-(1 → 6)-glucosyl megalosaccharide rich (L-IMS) and water-insoluble anionic ethyl red was firstly characterized in a comparison with inclusion complexation by cyclodextrins (CDs) to overcome the problem of poor solubility and bioavailability. Phase solubility studies indicated an enhancement of 3- and 9-fold over the solubility in water upon the presence of L-IMS and β-CD, respectively. (1)H NMR and circular dichrosim spectra revealed the dye forms consisted of 1:1 stoichiometric inclusion complex within the β-CD cavity, whereas they exhibited non-specific hydrophobic interaction, identified by solvent polarity changes, with L-IMS. The inclusion complex delivered by β-CD showed an uncompetitive inhibitory-type effect to azoreductase, particularly with high water content that did not promote dye liberation. Addition of the solid dye dispersed into coupled-enzyme reaction system supplied by L-IMS as the dye solubilizer provided usual degradation rate. The dye intermission in series exhibited successful removal with at least 5 cycles was economically feasible.
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Weeranuch
authors.initials: W
authors.lastname: Lang
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Kumagai
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Juri
authors.initials: J
authors.lastname: Sadahiro
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Janjira
authors.initials: J
authors.lastname: Maneesan
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Okuyama
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Haruhide
authors.initials: H
authors.lastname: Mori
authors.affiliation: Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Sakairi
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan. Electronic address: kimura@abs.agr.hokudai.ac.jp.
authors.forename: Atsuo
authors.initials: A
authors.lastname: Kimura
mesh_terms: D001391:Azo Compounds / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D001682:Biological Availability; D002942:Circular Dichroism; D004396:Coloring Agents / Q000302:isolation & purification*; D007700:Kinetics; D009844:Oligosaccharides / Q000737:chemistry*; D044367:Phase Transition; D066244:Proton Magnetic Resonance Spectroscopy; D011522:Protons; D011806:Quinolinium Compounds / Q000302:isolation & purification*; D012995:Solubility; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D009844:Oligosaccharides; D011522:Protons; D011806:Quinolinium Compounds; D047392:beta-Cyclodextrins; C003920:ethyl red; C031215:betadex
keywords: Amphiphilic surface; Azoreductase; Ethyl red; Megalo α-(1→6)-glucosaccharide; β-Cyclodextrin