Discovery of terpenoid and phenolic sweeteners from plants

Abstract

Several plant-derived compounds of the terpenoid and phenolic types have commercial use as sweeteners. In our research program directed toward the discovery of additional sweet compounds of these chemical classes, candidate sweet plants for laboratory investigation may be selected after scrutiny of the available literature, as a result of making inquiries in the field, and/or from a limited amount of organoleptic testing. Sweet-tasting plants are extracted according to a standard protocol, and preliminary safety testing is conducted before crude extracts or pure compounds are tasted. The practicality of using Mongolian gerbil electrophysiological and behavioral assays to monitor plant extracts and pure isolates has been examined. A number of sweet-tasting, plant-derived terpenoids and phenolics have been isolated and characterized, including the bisabolane sesquiterpenoids, hernandulcin and 4β-hydroxyhernandulcin, the labdane diterpene glycoside, gaudichaudioside A, the oleanane triterpenoid glycoside, periandrin V, the cycloartane triterpene glycosides, abrusosides A­E, the 3,4-seco-dammarane triterpene glycosides, pterocaryosides A and B, the semisynthetic dihydroflavonol, dihydroquercetin 3-acetate (4'-methyl ether), and the proanthocyanidin, selligueain A. Most of these new compounds are prototype "high-intensity" sweeteners that may be worthy targets for chemical synthesis or for semi-synthetic modification to produce substances with enhanced sweetness properties.