イボゲイン

解説C20H26N2O(310.43)．キョウチクトウ科Tabernanthe ibogaに含まれるインドールアルカロイドの一つ．この植物は西アフリカの赤道地域に限られて生育し，原住民は，通称，イボガ(iboga)とよんで，根皮のエキスを疲労防止，あるいは特有の幻覚，恍惚感を得るのに用いている．この作用は，成分として含まれるアルカロイドのためである．このアルカロイドをイボガアルカロイドとよぶ．"主アルカロイドがイボガインで，虹色の斜方晶系の針状晶．融点152～153 ℃．d420"－53°(95％ エタノール)．λmax 226，298 nm(log ε 4.39，3.93．メタノール)．水に不溶，エタノール，エーテル，クロロホルム，アセトン，ベンゼンに可溶．イボガアルカロイドには，ほかに，イボガミン，タベルナンチンなどがあり，類似の構造のアルカロイドがVoacanga属からも得られている．[CAS 83-74-9]森北出版「化学辞典（第2版）

説明This indole alkaloid occurs in the root of Tabernanthe iboga Baill. It was first examined in detail by Raymond-Hamet who assigned to it the empirical formula C19H24(26)ON2, now altered to that given above. The base forms colourless crystals from EtOH and is laevorotatory with [Q1D - 53° (EtOH). It is insoluble in Et20, slightly so in Me2CO or CHC1 3 but dissolves freely in MeOH, EtOH or H20. The alkaloid yields a hydrochloride, m.p. 299°C (dec.); lQlhs - 67° (MeOH) or - 37.3° (H20). It contains one methoxyl group and gives the typical indole reactions. On distillation with Zn dust or soda-lime it furnishes products which are indole derivatives with the ~-position free. In a manner similar to that of cocaine, the alkaloid potentiates the pressor action of adrenaline and abolishes the sino-carotid reflexes. Unlike cocaine, however, it also augments the action of tyramine and that of dl-ephedrine to a slight extent. Vincent and Sero have reported that it inhibits the action of serum cholinesterase.

純化方法Crystallise it from EtOH or aqueous EtOH and sublime it at 150o/0.01mm. It is soluble in organic solvents but insoluble in H2O. The hydrochloride, m 299-300o(dec), is soluble in H2O and alcohols. [Büchi et al. J Am Chem Soc 88 3099 1866, Rosenmund Chem Ber 108 1871 1975, Beilstein 23 III/IV 2742.]