The dihydroflavonol dihydroquercetin 3-acetate (1) was isolated as a sweet constituent of the young shoots of Tessaria dodoneifolia (Hook. & Arn.) Cabrera (Compositae). Compound 1 and dihydroquercetin 3-acetate 4'-(methyl ether) (2), a novel synthetic analogue of this natural product lead compound, were rated by a taste panel as being 80 and 400 times sweeter than a 2% w/v sucrose solution, respectively. Synthetic dihydroquercetin 4'-(methyl ether) (3) showed a reduced sweetness intensity when compared to 2, while (+)-dihydroquercetin (4) was devoid of sweetness. Dihydroflavonol derivatives 1-3 represent a new class of potentially noncaloric and noncariogenic intense sweeteners.