DMB-Asp-Phe-OMe    (DMB = 3,3-dimethylbutyl group)

(3-D model)

(3,3-dimethylbutyl)-L-aspartyl-L-phenylalanine 1-methyl ester

Only carbon, hydrogen, oxygen and nitrogen.

Neotame is a derivative of a dipeptide composed of two natural amino acids, L-aspartic acid (Asp) and L-phenylalanine (Phe). The partial sequence Asp-Phe-OMe is the same as found in aspartame, but free aspartame is never present during neotame use or metabolism.

Except a sweet taste in common with aspartame, neotame properties are original (higher sweetness potency, better stability, greater solubility, better resistance to temperature, different metabolism...). (more on Neotame vs. Aspartame)

All differences are connected with the presence of the dimethylbutyl (DMB) group substituting the nitrogen atom of aspartic acid.

Structure &
Sweet taste

Amino acids exist under two different configurations, L- is found in natural amino acids and proteins, while D- is scarcely found. In neotame, Asp and Phe moieties have the natural L-configuration.

The structural difference between L- and D- amino acids is minimal: L-isomer is the mirror image of D- (as right and left hands). This difference is easily discriminated by taste receptors. Their selectivity is so high that only one of the 4 four possible isomers, neotame, exhibits a sweet taste.

DMB-L-Asp-L-Phe-OMe   Extremely sweet (neotame)
DMB-L-Asp-D-Phe-OMe   Tasteless
DMB-D-Asp-L-Phe-OMe   Tasteless
DMB-D-Asp-D-Phe-OMe   Tasteless