Monellin, a sweet protein, was discovered in 1969 in the fruit of the West African shrub known as serendipity berry (Dioscoreophyllum cumminsii); it was first reported as a carbohydrate.

[1] In its natural form, monellin is composed of the two chains shown above (PDB: 3MON​), but the protein is unstable at high temperatures or at extremes of pH.

[1] To enhance its stability, single-chain monellin proteins were created in which the two natural chains are joined via a Gly-Phe dipeptide linker.

[12] Monellin can be useful for sweetening some foods and drinks, as it is a protein readily soluble in water due to its hydrophilic properties.

For instance, monellin has been expressed successfully in yeast (Candida utilis)[13] and synthesised by solid-phase method.

[14] The synthetic monellin produce by yeast was found to be 4000 times sweeter than sucrose when compared to 0.6% sugar solution.