Peptide Sweeteners. 6. Structural Studies on the C-Terminal Amino Acid of L-Aspartyl Dipeptide Sweeteners

Article abstract of DOI:10.1021/jm00378a023

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-α-aminobutyric acid benzyl ester were found to be sweet.In addition, chiral and achiral α,α-dialkylglycine and α-aminocycloalkanecarboxylic acids were incorporated into the dipeptides.The L-aspartic acid based dipeptide derivatives of α-aminoisobutyric acid methyl ester, α-aminocyclopropanecarboxylic acid methyl ester, α-aminocyclobutanecarboxylic acid methyl ester, and α-aminocyclopentanecarboxylic acid methyl ester are sweet.Dipeptides with α-aminocyclohexanecarboxylic acid methyl ester and α-aminocycloheptanecarboxylic acid methyl ester are bitter, whereas the analogues with α-aminocyclooctanecarboxylic acid methyl ester, α,α-diethylglycine methyl ester, and α-aminoisobutyric acid benzyl ester are tasteless.Aspects on chirality and effective volume of the C-terminal residue are discussed and correlated with taste.