Structure-taste Relationships of Aspartyl Tripeptide Esters

A series of twenty four analogues of l-α–Asp–Gly–Gly–OMe has been synthesized in relation to structural features of sweet peptides. The rule in the structure-taste relationships of dipeptides is held in the sweet aspartyl tripeptide esters. In order for the aspartyl tripeptide esters to be sweet, the second amino acid must have a d-configuration and a small, compact alkyl group (Me, Et, or i-Pr) at R2. An l-configuration of the third amino acid is required for a potent sweet taste. It has been concluded that the small alkyl group at R2 participates in binding with the receptor through a hydrophobic interaction and increases the sweetness potency.