title: Preparative separation and identification of derivatized beta-methylphenylalanine enantiomers by chiral SFC, HPLC and NMR for development of new peptide ligand mimetics in drug discovery.
abstract: A direct preparative purification of all four isomers of the unnatural amino acid beta-methylphenylalanine was achieved using supercritical fluid chromatography (SFC) with stacked-injection. Final purification of the Cbz-methyl ester derived isomers was performed on a Daicel Chiralpak AD-H column (20 mm x 250 mm), using 50:50 methanol/ethanol as the organic modifier and resulted in purification of over 3.4 g of material in 6.25 h with >90% total recovery. The absolute stereochemical assignment of the purified amino acids was determined through a combination of chiral HPLC, NMR and optical rotation studies. To our knowledge, this is the first reported preparative approach that has yielded all four compounds in a single chromatographic run.
authors.affiliation: Discovery Analytical Chemistry, Chemical and Screening Sciences, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426, USA. noglel@wyeth.com
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Nogle
authors.forename: Charles W
authors.initials: CW
authors.lastname: Mann
authors.forename: William L
authors.initials: WL
authors.lastname: Watts
authors.forename: Yingru
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000613:Aminobutyrates / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D015195:Drug Design; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009904:Optical Rotation; D013237:Stereoisomerism
chemical_list: D000613:Aminobutyrates; D008024:Ligands; C010535:2-amino-3-phenylbutanoic acid