Uses
Deserpidine is found and extracted fromthe roots of Rauwolfia canescens L., andApocyanaceae. Therapeutically, it is used asan antihypertensive agent.
Definition
ChEBI: Deserpidine is an alkaloid ester, a methyl ester, a benzoate ester, an organic heteropentacyclic compound and a yohimban alkaloid. It derives from a hydride of a yohimban.
Manufacturing Process
500 parts by weight of dried, finely ground roots of Rauwolfia canescens are
extracted batchwise with methanol at its boiling point, using the following
volumes and times, and filtering each extract while hot: 2,000 parts by
volume, 1 hour; 1,000 parts by volume, 45 minutes; 1,000 parts by volume,
30 minutes; 1,000 parts by volume, 30 minutes. The extracts are combined
and evaporated in vacuo to 75 parts by volume of a thick syrupy solution.
After the addition of 75 parts by volume of methanol and 150 parts by volume
of acetic acid of 15% strength with adequate mixing, the solution is extracted
with 2 portions each of 100 parts by volume of hexane. The combined hexane extracts are extracted with 15 parts by volume of acetic acid of 15% strength.
The latter extract is added to the above acetic acid phase which is then
extracted with 3 portions each of 75 parts by volume and 1 portion of 50
parts by volume of ethylene chloride.
The first three extracts are combined and washed with 60 parts by volume of
2 N sodium carbonate solution and then with 60 parts by volume of distilled
water. These washing solutions are saved and used for the washing of the 4th
and final ethylene chloride extract. The combined ethylene chloride extracts
are dried over sodium sulfate, filtered and evaporated in vacuo to a constant
weight of a tan, frothy solid. One part by weight of this residue is dissolved in
1.5 parts by volume of warm methanol and the solution cooled to 5°C for 18
hours, whereby crystallization of a mixture containing principally reserpine
sets in. After filtering this mixture and washing it with cool methanol, the
filtrate is freed of solvent in vacuo.
Two parts by weight of the resulting red-brown solid froth are triturated with 2
portions each of 25 parts by volume of benzene and filtered each time. The
benzene insoluble material is saved for further treatment. The benzene soluble
fraction is poured on to a column of 40 parts by weight of activated alumina
(Woelm, Activity Grade I) which is then eluted first with 3 portions each of 50
parts by volume of benzene and then with 6 portions each of 50 parts by
volume of benzene-acetone (9:1), the first of which benzene-acetone portions
had been used for extraction of the abovementioned benzene insoluble
material. The second of the 6 benzene-acetone elution fractions on removal of
the solvents gives a light tan solid froth which on crystallization from
methanol gives colorless prismatic needles of slightly impure deserpidine.
Rechromatographing of 1 part by weight of this substance on 20 parts by
weight of activated alumina (Woelm, Activity Grade I) using benzene and
benzene containing 0.1% methanol as eluting agents followed by
crystallization from methanol gives colorless prismatic needles of pure
deserpidine, melting at 228-232°C. Deserpidine obtained according to this
example can be made up into pharmaceutical preparations.
Health Hazard
The pharmacological properties of deserpi dine are similar to those of reserpine, causingsedation and tranquilization. Toxic effectsfrom high doses include drowsiness, depres sion, nausea, diarrhea, abdominal cramps,and hypotension. It is less toxic than reserpine. However, the poisoning effects may begreater than those of other Rauwolfia alka loids, such as rescinnamine. An oral LD50value in mice is 500 mg/kg.There is some evidence of its carcinogenic actions in animals and humans. Ratsgiven oral doses of 54 mg/kg over 77 weeksdeveloped blood tumor. In humans, it mayproduce tumors in skin and appendages.Cancer-causing properties of deserpidine,however, are not yet fully established.
