Gymnemic acid

Gymnemic acids are glycosides isolated from the leaves of Gymnema sylvestre (Asclepiadaceae). Gymnemic acids like ziziphin and hodulcine are anti-sweet compounds, or sweetness inhibitors. After chewing the leaves, solutions sweetened with sucrose taste like water.

Gymnemic acid [1]? itself is C₄₃H₆₆O₁₄^[1] (it has a 5 ring core with an attached sugar).

The simplest is gymnemagenin, C₃₀H₅₀O₆.^[2] The other members have variations at up to four sites around the 5 ring core.^[3]

More than 20 homologues of gymnemic acid are found in the leaves.^[4] Gymnemic acid 1 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.^[5]

See also

• other anti-sweetners :
  • Hodulcine, a dammarane-type triterpene glycoside from the leaves of Hovenia dulcis
  • Lactisole, Sodium 2-(4-methoxyphenoxy)propanoate
  • Ziziphin, a triterpene glycoside, C₅₁H₈₀O₁₈

References

1. Gymnemic acid shows structure
2. gymnemagenin
3. Synthesis, biology and clinical significance of pentacyclic triterpenes: a multi-target approach to prevention and treatment of metabolic and vascular diseases for structure list see external links below
4. AD kinghorn and CM Compadre. Less common high-potency sweeteners. In Alternative Sweeteners: Second Edition, Revised and Expanded, L O'Brien Nabors,Ed., New York, 1991. ISBN 0-8247-8475-8
5. Kurihara, Y. 1992. Characteristics of antisweet substances, sweet proteins, and sweetness-inducing proteins. Crit. Rev. Food Sci. Nutr. 32:231-252.

External links

• Photo of Gymnema sylvestre
• gymnema sylvestre shows structures of Gymnemic acid I, II, III, & IV, + 4 refs
• related images shows structures of gymnemagenin and gymnemic acid I to XIV.