title: Linear-polarized IR-spectroscopic and structural elucidation of glycyl-L-phenylalanyl-glycine hydrochloride monohydrate.
abstract: As a part of our spectroscopic and structural elucidation of small peptides, their salts and metal complexes, the polarized IR-spectroscopic and structural elucidation of the protonated form of glycyl-(L)-phenylalanyl-glycine as hydrochloride monohydrate (H-Gly-Phe-Gly-OHxHClxH(2)O) is reported. The obtained structure of the protonated tripeptide is supported by quantum chemical ab initio calculations at UHF level of theory and 6-31++G, showing only one stable conformer with two intermolecular NH(3)(+)OH(2) and (C=O)OHOH(2) hydrogen bonds. The N(terminus) amide O=C-N-H amide fragment is flat trans-configured with a dihedral angle value of 179.0(7)degrees, while the corresponding group at C(terminus) is with transoide-configurated and value of the dihedral angle of 151.1(3)degrees, respectively. In addition data of (1)H- and (13)C magnetic resonance spectroscopy (NMR), thermogravimetry (TGA), differential scanning calorimetry (DSC) and high performed liquid chromatography (HPLC) with tandem mass spectrometry (HPLC-MS/MS) as presented.
authors.affiliation: Department Of Analytical Chemistry 1 J Bourchier Blvd 1164-Sofia Bulgaria. BKoleva@chem.uni-sofia.bg
authors.forename: Bojidarka B
authors.initials: BB
authors.lastname: Koleva
mesh_terms: D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D009842:Oligopeptides; C530098:glycyl-phenylalanyl-glycine