title: A resolution approach of racemic phenylalanine with aqueous two-phase systems of chiral tropine ionic liquids.
abstract: Aqueous two-phase systems (ATPS) based on tropine type chiral ionic liquids and inorganic salt solution were designed and prepared for the enantiomeric separation of racemic phenylalanine. The phase behavior of IL-based ATPS was comprehensive investigated, and phase equilibrium data were correlated by Merchuk equation. Various factors were also systematically investigated for their influence on separation efficiency. Under the appropriate conditions (0.13g/g [C8Tropine]pro, 35mg/g Cu(Ac)2, 20mg/g d,l-phenylalanine, 0.51g/g H2O and 0.30g/g K2HPO4), the enantiomeric excess value of phenylalanine in solid phase (mainly containing l-enantiomer) was 65%. Finally, the interaction mechanism was studied via 1D and 2D NMR. The results indicate that d-enantiomer of phenylalanine interacts more strongly with chiral ILs and Cu(2+) based on the chiral ion-pairs space coordination mechanism, which makes it tend to remain in the top IL-rich phase. By contrast, l-enantiomer is transferred into the solid phase. Above chiral ionic liquids aqueous two-phase systems have demonstrated obvious resolution to racemic phenylalanine and could be promising alterative resolution approach for racemic amino acids in aqueous circumstance.
authors.affiliation: School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Haoran
authors.initials: H
authors.lastname: Wu
authors.affiliation: School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Shun
authors.initials: S
authors.lastname: Yao
authors.affiliation: School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Guofei
authors.initials: G
authors.lastname: Qian
authors.affiliation: School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Tian
authors.initials: T
authors.lastname: Yao
authors.affiliation: School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China. Electronic address: hangsong@vip.sina.com.
authors.forename: Hang
authors.initials: H
authors.lastname: Song
mesh_terms: D052578:Ionic Liquids / Q000737:chemistry*; D010649:Phenylalanine / Q000737:chemistry*; D013237:Stereoisomerism; D014326:Tropanes / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D052578:Ionic Liquids; D014326:Tropanes; D014867:Water; D010649:Phenylalanine; C005864:tropine
keywords: Aqueous two-phase systems; Chiral ionic liquid; Phase behavior; Racemic phenylalanine; Tropine type