title: Chiral ligand-exchange separation and resolution of extremely rigid glutamate analogs: 1-aminospiro[2.2]pentyl-1,4-dicarboxylic acids.
abstract: Owing to their chelation ability, a series of fully constrained L-Glu analogs formed by the spiro-union of two cyclopropane rings (1-aminospiro[2.2]pentyl-1,4-dicarboxylic acids, ASPED A-D), was submitted to chiral ligand-exchange chromatographic (CLEC) analysis. As the initial step, two methodologically different chiral devices were evaluated. A chiral stationary phase (CSP) obtained by dynamic coating of C(18) chains with the S-trityl-(R)-cysteine ((R)-STC) was used first with this objective. The lack of separation of the enantiomers of ASPED C and D prompted us to utilize the chiral mobile phase (CMP) prepared from O-benzyl-(S)-serine ((S)-OBS). The latter afforded complete separation of the four pairs of enantiomers. For all the pairs, quantum mechanical investigations shed light on the main features responsible for the different enantiomer recognition mechanism with (S)-OBS. The validated analytical method was then fruitfully adopted for semi-preparative-scale isolation of the enantiomers of ASPED C.
authors.affiliation: Dipartimento di Chimica e Tecnologia del Farmaco, Università degli Studi di Perugia, Via del Liceo 1, 06123, Perugia, Italy. natalini@chimfarm.unipg.it
authors.forename: Benedetto
authors.initials: B
authors.lastname: Natalini
authors.forename: Roccaldo
authors.initials: R
authors.lastname: Sardella
authors.forename: Nicola
authors.initials: N
authors.lastname: Giacchè
authors.forename: Samantha
authors.initials: S
authors.lastname: Palmiotto
authors.forename: Emidio
authors.initials: E
authors.lastname: Camaioni
authors.forename: Maura
authors.initials: M
authors.lastname: Marinozzi
authors.forename: Antonio
authors.initials: A
authors.lastname: Macchiarulo
authors.forename: Roberto
authors.initials: R
authors.lastname: Pellicciari
mesh_terms: D002852:Chromatography, Ion Exchange / Q000295:instrumentation / Q000379:methods*; D003998:Dicarboxylic Acids / Q000737:chemistry; D018698:Glutamic Acid / Q000031:analogs & derivatives / Q000302:isolation & purification*; D008024:Ligands; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D003998:Dicarboxylic Acids; D008024:Ligands; D018698:Glutamic Acid