Ziziphins activity

Several natural products, eg, gymnemic acid [122168-40-5] and ziziphin [73667-51-3], have also shown sweet-inhibiting activities. These are not allowed for foods in the United States, however. 

The sweetness-inhibiting substance ziziphin was isolated from the leaves of the plant Zizyphus jujuba (Rhamnaceae), which is native to China, by Kurihara et al 1 Like gymnemic acids, ziziphin is a glycoside of triterpene that suppresses sweetness in humans. Removal of the acyl group under mild hydrolytic conditions led to complete abolishment of its antisweet activity. 

Sodium dodecyl sulfate, the gymnemic acids and the ziziphins have all been termed "surface active" taste modifiers because they all possess detergent-like properties. These molecules all have a polar and a non-polar end and they are capable of penetrating the phospholipid membranes that are believed to be components of sweetness receptors. Any speculation about the mechanism of action of these substances must take into account the experimental observations concerning miraculin, monellin, and thaumatin, which were presented at the beginning of this article. Those observations suggested that transport of the modifier to the cell s interior was not occurring and the inhibition effect is manifested at the surface of the cell. 

The bark of Scutia buxifolia (Rhamnaceae) contains scut-ianine A, B (20), C, D, F (21), and G (22). Similar compounds have been isolated from the roots of Melochia tomen-tosa (23 and 24). A number of 14-membered-ring peptide alkaloids have been isolated from members of the genus Zizyphus (Rhamnaceae) (Fig. 37.8). An alkaloid from diis family, ziziphin (25), blocks activity of the sugar (but not the salt) receptors of flies (Stiidler, 1984). 

The triterpene glycoside ziziphin isolated from the leaves has sweetness inhibitory (anti-sweeteness) activity in humans. ... 

Among eight flavonoids in the seeds, swertisin and spinosin possess significant sedative activity (53). The fresh leaves contain jujubasaponins, including ziziphin, which shows sweetness-inhibiting activity (54, 55). 

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