|Budget Amount *help
¥4,900,000 (Direct Cost : ¥4,900,000)
Fiscal Year 1991 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1990 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1989 : ¥3,900,000 (Direct Cost : ¥3,900,000)
In a preliminary study, the neutral fraction of the reethanol extract of the chinese trditional medicine CorydaUs tuber was shown to contain dopamine D2 receptor binding substances. Detailed studies revealed, however, the active principles were in fact not neutral, but weakly basic phenolic alkaloids such as isocorypalmine. Tids led us to examine further the presence of substances having binding activity to the central neuroreceptors Dl, D2 and 5-Hl'(5hydroxyttyptamine)la, lb, lc in other folk medicinal plants, by means of combination of chemical and pharmacological methods.
Binding assays demonstrated that Anisonia elliptica contained substances. binding to the 5-HTla receptor. The active principles were identified as tetrahydroalstonine, beta-yoliimbine and yolfimbine. These three endole alkaloids had, however, stronger binding activity for tlie adrenergic alpha2 receptor and therefore, were not selective. From the imdian medicinal plant Lytsea glutinosa were isolated as selective Dl receptor binding substances isoboldine, reticuline, and a new alkaloid 2-hydroxylmethoy-10, 11-methlenedioxynoraporphine, together with nonselective Dl/5-HTla binding substance boldine.
Endogeneous dopamine and 5-hydroxytryptandne are known as key compounds for some mental diseases. The above alkaloids can therefore be useful lead compounds for new antipsychotic drugs.