title: 1,1'-Binaphthyl-based imidazolium chemosensors for highly selective recognition of tryptophan in aqueous solutions.
abstract: A type of 1,1'-binaphthyl-based imidazolium chemosensor module has been synthesized for the highly selective recognition of tryptophan (Trp) among the eleven alpha-amino acids investigated in aqueous solutions via synergistic effects of multiple hydrogen bonding and electrostatic interactions. These results have demonstrated that the C-2 hydrogen atom of the imidazolium ring plays a key role as a hydrogen bond donor. The UV/vis, fluorescence and mass spectral studies have indicated that a 1 : 1 complex is formed between the host and tryptophan. The binding affinity and selectivity of the cleft-like receptor (R)- with l-Trp are superior to those of (R)-. In spite of an inferior selectivity towards various aromatic amino acids, the macrocyclic (R)- displays a remarkable enantiodiscrimination for the two enantiomers of tryptophan with a K(D)/K(L) value as high as 6.2.
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, West China Hospital, West China Medical School, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Song
authors.initials: S
authors.lastname: Qin
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Su
authors.forename: Fei
authors.initials: F
authors.lastname: Yang
authors.forename: Jingsong
authors.initials: J
authors.lastname: You
authors.forename: Changwei
authors.initials: C
authors.lastname: Hu
authors.forename: Rugang
authors.initials: R
authors.lastname: Xie
authors.forename: Jingbo
authors.initials: J
authors.lastname: Lan
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D018360:Crystallography, X-Ray; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009281:Naphthalenes / Q000737:chemistry*; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013379:Substrate Specificity; D014364:Tryptophan / Q000032:analysis* / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D007093:Imidazoles; D009281:Naphthalenes; D012996:Solutions; D014867:Water; C031721:naphthalene; D014364:Tryptophan