Peptide sweeteners. 6. Structural studies on the C-terminal amino acid of L-aspartyl dipeptide sweeteners.
Stereochemical and structural aspects of the variations in the C-terminal residue of L-aspartyl-L-phenylalanine methyl ester have been investigated. Novel configurational analogues such as L-aspartyl-D-alanine benzyl ester and L-aspartyl-D-alpha-aminobutyric acid benzyl ester were found to be sweet. In addition, chiral and achiral alpha, alpha-dialkylglycine and alpha-aminocycloalkanecarboxylic acids were incorporated into the dipeptides. The L-aspartic acid based dipeptide derivatives of alpha-aminoisobutyric acid methyl ester, alpha-aminocyclopropanecarboxylic acid methyl ester, alpha-aminocyclobutanecarboxylic acid methyl ester, and alpha-aminocyclopentanecarboxylic acid methyl ester are sweet. Dipeptides with alpha-aminocyclohexanecarboxylic acid methyl ester and alpha-aminocycloheptanecarboxylic acid methyl ester are bitter, whereas the analogues with alpha-aminocyclooctanecarboxylic acid methyl ester, alpha, alpha-diethylglycine methyl ester, and alpha-aminoisobutyric acid benzyl ester are tasteless. Aspects on chirality and effective volume of the C-terminal residue are discussed and correlated with taste.
D001218:Aspartame / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002621:Chemistry; D002855:Chromatography, Thin Layer; D004151:Dipeptides / Q000138:chemical synthesis*; D006801:Humans; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009904:Optical Rotation; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship; D013549:Sweetening Agents / Q000138:chemical synthesis*; D013649:Taste
D004151:Dipeptides; D007202:Indicators and Reagents; D013549:Sweetening Agents; D001218:Aspartame