Hovenia dulcis Thunb

Hovenia dulcis Thunb. Zhi Bei Zi (Japanese raisin tree) (stem bark) Ebelin lactone, hovenosides, potassium malate, potassium nitrate.27-50 For rectal diseases, constipation, infantile convulsions, antispasmodic, febrifuge. 

Subsequent to the isolation of the dammarane-type triterpenoid glycosides jujuboside B (112), hodulosides I-V (113-117), hovenoside I, and saponins C2, E, and H (122-125) as sweetness inhibitors from the leaves of Hovenia dulcis Thunb. var. tomentella Makino [139], hodulosides VII-X (118-121) were isolated as sweetness-inhibitory agents [140]. Hodulosides I (113) and II (114) have hovenolactone (151) as their aglycone which is the same compoimd as in saponins E (124) and H (125). Hodulosides Ill-V and VII-X (115-121) are based on two different danunarane-type aglycone structures, however [139,140]. The sweetness-inhibitory potencies of hodulosides are shown in Table 2. The sweetness-inhibitory potency of hoduloside X (121) was not determined [140]. 

A number of non-proteinaceous substances of plant origin are known that induce or inhibit the sensation of sweetness. Sweetness inducers and enhancers from plants include cynarin, chlorogenic acid, caffeic acid, and arabinogalactin (larch gum) (33). A synthetic compound, 2-(4-methoxyphenoxy)propanoic acid, which is also a constituent of roasted coffee beans, is currently on the market as a sweetness inhibitor (33). Several oleanane-type triterpene esters with sweetness-inhibitory activity occur in Gynmema sylvestre leaves (33,116,117), with dammarane-type saponins with similar effects having been reported recently from the leaves of Hovenia dulcis Thunb. (Rhamnaceae) (118) and Ziziphusjujuba Mill. (Rhamnaceae) (33,119,120). 

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