Structure-taste Relationship of Novel α- l -Aspartyl Dipeptide Sweetners

A sweetness potency was found in novel α-l-aspartyl dipeptide analogs which were quite stable on heating in an aqueous solution. The insertion of a methylene group into the peptide chain of α-l-aspartyl dipeptide esters mostly decreased the potency of the sweetness. However, the further exchange of the carbonyl and oxygen functions with each other on the ester group of a C-terminal β-alkyl-β-aminopropionic acid was found to increase the sweetness. Thus, N-(α-l-aspartyl)-O-pivaroyl-d-alaninol, N-(α-l-aspartyl)-O-cyclobutylcarbonyl-d-alaninol and N-(α-l-aspartyl)-O-cyclopropylcarbonyl-d-alaninol were all more than 200 times as sucrose.