Wikipedia
Ziziphin, a triterpene glycoside which exhibits taste-modifying properties, has been isolated from the leaves of Ziziphus jujuba ( Rhamnaceae).
Among ziziphin's known homologues found in this plant, it is the most anti-sweet. However, its anti-sweet activity is less effective than gymnemic acid 1, another anti-sweet compound glycoside isolated from the leaves of Gymnema sylvestre ( Asclepiadaceae).
Ziziphin reduces perceived sweetness of most of the carbohydrates (e.g. glucose, fructose), bulk sweeteners, intense sweeteners (natural: steviol glycoside – artificial: sodium saccharin and aspartame) and sweet amino acids (e.g. glycine). However, it has no effect on the perception of the other tastes, bitterness, sourness and saltiness.