(Corynanthe yohimbe) INTRODUCTION : Yohimbe's active compound, yohimbine, is extracted primarily from the bark of Corynanthe yohimbe, syn. Pausinystalia yohimba. The tree is native to the French Congo and the Cameroons, and has been used ritually for centuries. Yohimbe-bark is valued for it's aphrodisiastic properties. It is possible that the ancient Egyptians knew of the existence of the yohimbe-tree and imported the bark from West Africa. Yohimbine is also present in other Corynanthe species. EFFECTS : In lower doses it has stimulating properties and in higher doses it acts as a mild hallucinogenic. Characteristic effects consist of stimulation of the sexual organs, mild changes in perception, alertness, activeness and salivation. Autonomic effects: nausea, pupillary dilation, tremor, accelerated heartbeat, rise of blood pressure, nervousness and anxiety. Yohimbine is an activator of schizofrenic psychoses. DURATION : The effects usually appear within half an hour after ingestion and last for two to four hours. Dosage and preparation : The plant material is usually ingested, but it may also be snuffed. 6-10 teaspoons of yohimbe powder should be provided per person. When taken orally, the effects start 15-30 minutes after ingestion and when snuffed, the effects start within 5 minutes. The bark of P. yohimbe contains 1.7-3.4 % yohimbine by weight; yobimbine acts as a stimulant in doses of 3×(5-10)mg/ day and acts as a hallucinogenic between 15-25 mg Overdosing apparently doesn't cause severe problems. Figure: Powdered Yohimbe Botanical aspects : P. yohimbe belongs to Rubiaceae and native to tropical forests of the French Congo, Nigeria and the Cameroons. This evergreen tree has oval leaves (7-13 cm across), a brown bark and grows 30 meter in height. The tree can be propagated vegetatively (by cuttings) and through seeds, but little data concerning propagation is known.  Figure: Pausinystalia yohimbe Phytochemistry : The cyclic-indole alkaloids (Yohimbine alkaloids) that are present in the bark of P. yohimbe are closely related to the Quebracho-blanco- and Rauwolfia serpentina alkaloids . Yohimbine (=corynine, quebrachine), a-yohimbine (=corynanthidine, isoyohimbine), b-yohimbine, d-yohimbine (=(-)-Ajmalicine), corynanthine, corynanthein, dihydrocorynantheine, allo-yohimbine (=dihydroyohimbine), Pseudo-yohimbine and tetrahydromethylcoynantheine have been isolated. The bark of P. yohimbe has a total alkaloid content of 2-15 %, but 1.7-3.4% by weight is yohimbine.  Pharmacology : The pharmacological action of the main active principle, yohimbine, is manifold in that it has cholinergic, antiserotonine- and alpha-adrenergic blocking properties. d-yohimbine possesses antihypertensive and sedativing properties. The actions which are responsible for the libido enhancing effect of yohimbine are unknown, but it appears that its specific alpha-adrenergic receptor blocking property is involved . The psychoactive effect of yohimbine (changes in perception) might be the result of mutual influence on various serotonergic receptors. Modifiers : - Pretreatment with amobarbital prevents all yohimbine's autonomic effects, except blood pressure . - Librium partially blocks the yohimbine effect. It reduces anxiety and tension . - Imipramine (tri-cyclic antidepressants) greatly increases the action of yohimbine . - Alcohol causes a dsangerous decrease of blood pressure DANGEROUS COMBINATIONS : Yohimbine should not be used by people who suffer from ailment or injury of kidneys, liver, heart. When taken within 48 hours of haven taken any amphetamines, breathing difficulties and a severe blood pressure drop can arise. References 1. [Efron/ Holmstedt/ Kline, 1967] 2. [Gottlieb] 3. [Hoffer/ Osmond, 1967] 4. [Hoffmann/ Schultes, 1973] 5. [Niesink/ Vries/ Hollinger, 1995] 6. [Ratsch, 1998] 7. [Shulgin, 1997] 8. [Stafford, 1974] 9. [Karrer, 1950] 10. [Forth/ Henschler/ Rummel/ Fostermann/ Starke, 2001] 11. [Trachsel/ Richard, 2000] (Text by Wout. Please mail here for your comments) |