Corynanthe yohimbe alkaloids

Yohimbine (36) is a well-known and reasonably available alkaloid from Corynanthe yohimbe, inter alia. For this reason, and partly because of its intrinsic pharmacological activity (including reputed aphrodisiac activity), chemists have frequently studied its properties. Oppenauer oxidation is usually attended by saponification and decarboxylation in this series, and yohimbone (37) is the product. Wolf-Kischner reduction to yohimbane (38), followed by sodium hydride mediated alkylation, leads to the analgesic agent, mimbane (39). °... 

Material Yohimbine is one of several indole-based alkaloids found in Corynanthe yohimbe, Rauwolfia serpentina, and several other plants. 

Yohimbine is a major carboline alkaloid in the bark of Pausinystalia species, such as Pausinystalia yohimbe (Corynanthe yohimbe), Pausinystalia macrocerus, Pausinystalia paniculata, and Pausinystalia trillesi. It is also found in Pseudocinchona africana and Rauwolfia canescens. 

The stem bark of P. yohimbe (= P. johimbe Corynanthe yohimbe), "yohimbe as it is known in Cameroon, Gabon and Congo is used traditionally as an aphrodisiac and stimulant to prevent sleep (41). The bark contains 1-6% of indole alkaloids, most of which are yohimbane-type alkaloids, the main one being yohimbine [7], which is structurally related to reserpine [8] (89). Yohimbine is a selective inhibitor of a-2- adrenergic receptors and, while at low dose it has hypertensive activity, at high dose it is hypotensive (vasodilation of peripheral vessels). It is the vasodilation of peripheral vessels, and especially vasodilation of the corpus cavemosum, which is the cause of the reputation of yohimbine as an aphrodisiac (90). Tests have shown, indeed, that increased... 

Yohimbine, an indolaUcylamine alkaloid, is chemically similar to reserpine. It is the principal alkaloid of the bark of the West African Corynanthe yohimbe tree and is also... 

Corynanthe yohimbe (Pausinystalia yohimbe Rubiaceae) is a evergreen tree native to the southern part of Africa and to Cameroon, Nigeria, and Zaire. Occasionally it is planted in tropical countries. Its bark coontains a total of 0.3%-1.5% alkaloids. The well known indole alkaloid yohimbine has been obtained as a major alkaloid from the bark. The bark has been used traditionally as an aphrodisiac by African natives. Yohimbine hydrochloride is used as an adrenergic blocker for humans. 

Y. is the main alkaloid of many Aspidosperma species, it also occurs in Rubiaceae such as Corynanthe johimbe i=Pausinystalia) and related trees as well as in some Apocynaceae (e. g., Rauvolfia and Vinca species). Y. is structurally related to the Rauvolfia alkaloids, e. g., reserpine. Y. is the methyl ester of yohimb(in)ic acid (C20H24N2O3, Mr 340.42, mp. 280-300°C). In medicine Y. is used especially in the form of its more water-soluble hydrochloride (decomp. at 302 °C) as a... 

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