Glycyrrhetinic acid is a pentacyclic triterpenoid amyrin derivative obtained from the hydrolysis of glycyrrhizic acid ^*. It is used in flavouring and it masks the bitter taste of drugs like aloe and quinine. It is effective in the treatment of peptic ulcer and as an expectorant.

In glycyrrhetinic acid the functional group (R) is a hydroxyl group. Research in 2005 ^{* demonstrated that with a proper functional group a very effective glycyrrhetinic artificial sweetener can be obtained. When R is an anionic NHCO(CH₂)CO₂K side chain, the sweetening effect is found to 1200 times that of sugar (human sensory panel data). A shorter or longer spacer reduces the sweetening effect. One explanation is that the taste bud cell receptor has 1.3 nanometers (13 angstroms) available for docking with the sweetener molecule (lock-and-key model). In addition the sweetener molecule requires three proton donor positions of which two reside at the extremities to be able to interact efficiently with the receptor cavity.}

References

• ^{Molecular Design of Sweet Tasting Compounds Based on 3β-Amino-3β-deoxy-18β-glycyrrhetinic Acid: Amido Functionality Eliciting Tremendous Sweetness So Ijichi Seizo Tamagaki Chemistry Letters Vol. 34 (2005) , No. 3 p.356 [http://www.jstage.jst.go.jp/article/cl/34/3/34_356/_article Abstract}

Sweeteners | Carboxylic acids | Flavors