Gymnemic acid

Gymnemic acids are a class of chemical compounds isolated from the leaves of Gymnema sylvestre (Apocynaceae). They are anti-sweet compounds, or sweetness inhibitors. After chewing the leaves, solutions sweetened with sugar taste like water.

Chemically, gymnemic acids are triterpenoid glycosides. The central structure is the aglycone gymnemagenin (C₃₀H₅₀O₆). This is adorned with a sugar such as glucuronic acid and with various ester groups. These variations give rise to the different gymnemic acids. More than 20 homologs of gymnemic acid are known.

Gymnemic acid I has the highest anti-sweet properties. It suppresses the sweetness of most of the sweeteners including intense artificial sweeteners such as aspartame and natural sweeteners such as thaumatin, a sweet protein. The anti-sweet activity is reversible, but sweetness recovery on the tongue can take more than 10 minutes.

Example chemical structures

See also

Other anti-sweeteners:

• Hodulcine, a dammarane-type triterpene glycoside from the leaves of Hovenia dulcis
• Lactisole, sodium 2-(4-methoxyphenoxy)propanoate
• Ziziphin, a triterpene glycoside, C₅₁H₈₀O₁₈
• Gurmarin

References