The artificial sweetner aspartame is the methyl ester of the dipeptide

Aspartame is the most successful and widely used artificial sweetener. It is roughly 100 times as sweet as cane sugar. It is methyl ester of dipeptide formed from aspartic acid and phenylalanine. Use of aspartame is limited to cold foods and soft drinks because it is unstable at cooking temperature.
Various artificial sweeteners are Aspartame, Alitame, Saccharin, Sucrolose etc.