title: pH recycling aqueous two-phase systems applied in extraction of Maitake β-Glucan and mechanism analysis using low-field nuclear magnetic resonance.
abstract: In this paper, a recycling aqueous two-phase systems (ATPS) based on two pH-response copolymers PADB and PMDM were used in purification of β-Glucan from Grifola frondosa. The main parameters, such as polymer concentration, type and concentration of salt, extraction temperature and pH, were investigated to optimize partition conditions. The results demonstrated that β-Glucan was extracted into PADB-rich phase, while impurities were extracted into PMDM-rich phase. In this 2.5% PADB/2.5% PMDM ATPS, 7.489 partition coefficient and 96.92% extraction recovery for β-Glucan were obtained in the presence of 30mmol/L KBr, at pH 8.20, 30°C. The phase-forming copolymers could be recycled by adjusting pH, with recoveries of over 96.0%. Furthermore, the partition mechanism of Maitake β-Glucan in PADB/PMDM aqueous two-phase systems was studied. Fourier transform infrared spectra, ForteBio Octet system and low-field nuclear magnetic resonance (LF-NMR) were introduced for elucidating the partition mechanism of β-Glucan. Especially, LF-NMR was firstly used in the mechanism analysis in partition of aqueous two-phase systems. The change of transverse relaxation time (T2) in ATPS could reflect the interaction between polymers and β-Glucan.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, Department of Bioengineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Huiyun
authors.initials: H
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Bioreactor Engineering, Department of Bioengineering, East China University of Science and Technology, Shanghai 200237, China. Electronic address: caoxj@ecust.edu.cn.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Cao
mesh_terms: D000180:Acrylic Resins; D048691:Grifola; D006863:Hydrogen-Ion Concentration; D059625:Liquid-Liquid Extraction; D009682:Magnetic Resonance Spectroscopy; D059027:Recycling; D013696:Temperature; D014867:Water / Q000737:chemistry*; D047071:beta-Glucans / Q000302:isolation & purification*
chemical_list: D000180:Acrylic Resins; D047071:beta-Glucans; D014867:Water
keywords: G. frondosa; Low-field nuclear magnetic resonance; Recycling aqueous two-phase systems; Transverse relaxation time (T(2)); β-Glucan