title: Enantioselective photolysis and quantitative chiral analysis of tryptophan complexed with alkali-metalized L-serine in the gas phase.
abstract: The enantioselective photolysis of a cold gas-phase noncovalent complex of tryptophan with alkali-metalized L-serine, M(+) (L-Ser)(Trp) (M = Na and Li), was examined using a tandem mass spectrometer containing a variable-temperature ion trap. CO2 loss from Trp in the clusters was enantiomerically selective in ultraviolet excitation with linearly polarized light. M(+) (L-Ser) promoted the enantioselective photolysis of Trp as a chiral auxiliary. The enantioselective photolysis of the D-enantiomer was applied to a quantitative chiral analysis, in which the optical purity of tryptophan could be determined by measuring the relative abundance ratio R of the enantioselective CO2 loss to the chiral-independent evaporation of L-Ser in a single photodissociation mass spectrum of M(+) (L-Ser)(Trp).
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Osaka, Japan.
authors.forename: Akimasa
authors.initials: A
authors.lastname: Fujihara
authors.forename: Naoto
authors.initials: N
authors.lastname: Maeda
authors.forename: Shigeo
authors.initials: S
authors.lastname: Hayakawa
mesh_terms: D005740:Gases / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D010782:Photolysis; D012694:Serine / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry; D014364:Tryptophan / Q000032:analysis* / Q000737:chemistry*
chemical_list: D005740:Gases; D012694:Serine; D014364:Tryptophan; D008094:Lithium; D012964:Sodium
keywords: amino acid; chiral auxiliary; chiral recognition; optical purity; quantitative analysis