title: Synthesis and characteristics of an aspartame analogue, L-asparaginyl L-3-phenyllactic acid methyl ester.
abstract: An aspartame analogue, L-asparaginyl L-3-phenyllactic acid methyl ester was synthesized with aspartic acid replaced by asparagine and peptide bond replaced by ester bond. The aspartic acid of aspartame could be replaced by asparagine as reported in the literature. In this analogue, the hydrogen of amide group could still form a hydrogen bond with the oxygen of ester bond and the ester bond was isosteric with peptide bond. However, the product was not sweet, showing that the peptide bond could not be replaced by ester bond. The peptide C-N bond behaves as a double bond that is not free to rotate and the C, O, N and H atoms are in the same plane. The replacement of peptide bond by ester bond destroyed the unique conformation of peptide bond, resulting in the loss of sweet taste.
authors.affiliation: Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Hu
authors.initials: H
authors.lastname: Tao
authors.forename: Da-Fu
authors.initials: DF
authors.lastname: Cui
authors.forename: You-Shang
authors.initials: YS
authors.lastname: Zhang
mesh_terms: D001218:Aspartame / Q000031:analogs & derivatives* / Q000138:chemical synthesis*; D002244:Carbon / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004952:Esters / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008956:Models, Chemical; D009584:Nitrogen / Q000737:chemistry; D009842:Oligopeptides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010452:Peptide Biosynthesis; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D004952:Esters; D009842:Oligopeptides; D010455:Peptides; C495443:asparaginyl-3-phenyllactic acid methyl ester; D002244:Carbon; D006859:Hydrogen; D009584:Nitrogen; D010100:Oxygen; D001218:Aspartame