C.R. Acad. Sci. Vol. 133:748 (1901) Translation from the French by
William J. Gladstone (2005)
PLANT CHEMISTRY. Concerning Iboga, its excitement-producing
properties, its composition, and the new alkaloid it contains, ibogaine.
Communication by Messrs. J. Dybowski and Ed. Landrin, presented by M.
Henri Moissan. (Extract).
"During travels in the French Congo, we had occasion to observe that
the natives of the territories situated between the mouth of the Ogoué
and of the Mayumbé use the woody part of a plant which is known in the
Lower Ogoué and the Fernand Naz by the name of Iboga and that the
Pahouins call Aboua.
Its constant use must have contributed to making this species scarce
and even rare in certain regions. They claim that absorbing a certain
quantity of the plant will give renewed strength and make it possible to
withstand fatigue for a long time, doing away with any need for sleep.
They also attribute aphrodisiac properties to it.
The men who paddle canoes use it regularly. When we questioned them,
they always said that Iboga had the same action as alcohol on them, but
without clouding their mind; apparently, this was meant to refer to the
excitement-inducing properties of this plant.
These properties were described a long time ago. At the March 6th,
1889 session of the Linnaean Society, Professsor Baillon described Iboga
on the basis of the samples brought back from the Cape Lopez region by
Griffon du Bellay. In the description he gave, he stated:
It is suffrutescent in appearance and its branches reach
a height of approximately 1.5 meters. They originate from a very large
ramified root that has a gray, bitter bark, and that is the part of the
plant that the Gabonese eat.
... I am naming this plant Tabernanthe Iboga, but I still cannot say
whether this type will be classified in the genus Tabernoemontana in a
section, or whether it will constitute a genus in the Arduineae series.
A more thorough study of the fruit shows that the lower part of the
ovary is bilocular and that the upper part is unilocular and has a
parietal placentation, as has been observed in some Melodinus plants
where there is a single fruit, not formed by two distinct berries: this
is how the fruit in Iboga is formed. It therefore appears that we have
reason to believe that Tabernanthe plants are more directly related to
the Arduineae, and that this is the series in which they should
definitively be classified.
The active ingredient of Iboga does not seem to occur only in the
bark, as Baillon indicates, but throughout the wood and principally in
the roots that are used particularly by the natives. These roots are
what we studied.
Iboga owes its properties to a particular alkaloid that we have been
able to isolate and to which we have given the name of ibogaine.
Since this alkaloid is not found free in the root, we extracted it by
the following process: milk of lime is added to the finely powdered
root; the mixture is dried and then stirred with ether. The ether is
separated in turn and stirred with water acidified to 1:10 with sulfuric
acid which takes up the alkaloids in solution and converts them to
sulfate. This treatment is repeated several times to extract the Iboga
completely, then the acid liquids are combined and treated with caustic
soda in solution that precipitates the crude alkaloids. These are an
amorphous alkaloid mixture, whose properties we shall return to later,
and a clearly crystallized alkaloid. Since the latter is is far less
soluble in alcohol than the former, it is separated by successive
purifications in alcohol.
By means of this process, we were able to extract from 6 to 10 g/kg
of ibogaine from Iboga, depending on the samples we tested. As we can
see, this is a relatively high yield.
The ibogaine thus obtained is a perfectly crystallized substance with
a slightly amber color; the crystals are clear-cut, several millimeters
in length, they are long transparent prisms with a rectangular base with
inclined facets at the end (straight prism orthorhombic system).
Ibogaine is almost completely insoluble in water, very soluble in
alcohol, especially when warm. At a temperature of 15°C, 1 g will
dissolve in 28 g of 95° alcohol, and, on boiling, in 4 g of alcohol. It
is also very soluble in ether, chloroform, benzene, and most solvents.
It melts at a temperature of 152°C to a clear yellow liquid; it has a
very particular stryptic taste, somewhat similar to that of cocaine.
It rotates plane-polarized light to the left. The rotation in alcohol
solution (95° alcohol) was found to be: _ = -48° 32'. This determination
was performed with a Laurent polarimeter in a 20 cm tube at a
temperature of 15°C. The rotation found was 1° 56' per gram of alkaloid
in solution in 50 cc of alcohol.
Ibogaine is readily oxidized in air, turning a brownish yellow and
appearing to change into an uncrystallizable compound. Its saline
solutions are turned to a white precipitate by Mayer's reagent, by
tannin (an alcohol-soluble precipitate), by a sublimate and by
phosphoantimonic acid. Iodinated potassium iodide gives a brownish red
precipitate; bismuth-potassium double iodide gives a golden yellow
With sulfuric, nitric, acetic, benzoic acids, ibogaine forms salts
that are neutral to litmus paper but uncrystallizable. On the contrary,
the hydrochloride crystallizes perfectly, especially in acid
solution.We shall continue with the study of the other chemical properties of
ibogaine, to which we propose to return.
After analysis, the average of five combustions led us to assign it
the formula C52H66Az6O2.
Physiological experiments currently in progress have established the
energy-inducing action of ibogaine; like that of Iboga, it is exerted in
particular on the system of the medulla oblongata, producing a
particular excitement at a low dose; at a massive dose, the effects are
similar to those of the absorption of an excess of alcohol.
Return to What's New