Page 98 - Phytochemistry 2 (06-PG 605)

Yohimba alkaloids
Yohimbine (Aphrodine)
Occurrence
Yohimbine occurs in the barks of the West African tree
Pausinystalia yohimbe, family Rubiaceae. The bark contains about
6% total alkaloids, the main of which is Yohimbine.

N
N
H

Yohimbine

H3COOC

OH

Properties

Yohimbine occurs as orthorhombic needles from dilute

ethanol, m.p. 234˚C. It is slightly soluble in water, soluble in

ethanol, chloroform and hot benzene, sparingly soluble in ether.

Tests for identification

 On treatment of yohimbine with concentrated H2SO4 and

crystals of K2Cr2O7, violet streaks are obtained that turns blue

then green (c.f. strychnine).

 Yohimbine gives with Mandalin's reagent a blue colour that

turns to green (c.f. strychnine that gives a violet colour which

changes to red).

Uses

Yohimbine is mainly used as an aphrodisiac drug.

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