Selligueain A, a novel highly sweet proanthocyanidin from the rhizomes of Selliguea feei.

Selligueain A, a novel sweet trimeric proanthocyanidin with a doubly linked A unit, has been isolated from the rhizomes of Selliguea feei collected in Indonesia. The structure of this substance was established as epiafzelechin-(4 beta-->8, 2 beta-->O-->7)-epiafzelechin-(4 beta-->8)-afzelechin [1], on the basis of a combination of spectral and chemical methods. The compound was not acutely toxic for mice and not mutagenic in a forward mutation assay utilizing Salmonella typhimurium strain TM677. Selligueain A [1] was rated by a taste panel as exhibiting about 35 times the sweetness intensity of a 2% w/v aqueous sucrose solution, and at a concentration of 0.5% w/v in H2O was perceived as pleasant-tasting rather than astringent.