Monoterpene Alkaloid Isolated From Mucuna Pruriens
Authors: Samir Malhotra, Amrit Pal Singh,
A new alkaloidal principle was isolated from the leaves and stem of Mucuna pruriens. The plant is a reputed remedy for sexual and nervous diseases in Ayurveda. Authentic plant material was collected from reputed source, the extraction was carried out with soxhlet apparatus using carbon disulfide as solvent. The extract of the leaves and stem of the plant was tested positive for alkaloid using confirmatory tests. High performance liquid chromatography (HPLC) was used for determination of alkaloids in the extract. The calibration graph of peak area for alkaloids was noticed.
(Keywords: Mucuna pruriens, Leguminoseae/alkaloids/L-dopa).
Mucuna pruriens is a plant of the family Leguminoseae and is indigenous to tropical countries like India and West Indies. The plant is a climbing legume with long, thin branches and opposite, lanceolate leaves 15 to 30 cm in length. The flowers grow in racemes in 2 or 3. The fruit of the plant is pod, which is thick and leathery. It covered with long stiff hairs that are responsible for itching in workers involved in collection of the plant. Mucuna pruriens is a reputed remedy of Ayurveda in nervous and sexual diseases.
It is commonly known as cowhage (Latin) and kiwanch (kapikacchu) (Sanskrit). Traditionally, Mucuna pruriens find use in number of diseases and is commonly used as carminative, hypotensive & hypoglycemic agent. From phytochemistry point of view, the drug contains L-dopa, tryptamine alkaloids, lecithin and tannins. All these compounds are known to exist in the seeds. In continuation of the chemical analysis medicinal plants indigenous to Chandigarh region, we report for the first time the detection and extraction of alkaloidal principle from the leaves and stem of the Mucuna pruriens.
Materials and Methods
1. Sampling: Before evaluation of Mucuna pruriens, a sample was drawn for analysis. Considerable care was exercised to ensure that this sample was truly representative. The fresh plant was collected from Sohana, near 8 Mohali in February 1999
2. Preliminary examination: Macroscopic and quantitative microscopic examination (lycopodium score method) for foreign matter was carried out and it was removed.
3. Extraction: The drug was dried in shade and was pulverized using Waring blender. The drug was passed through various sieves to ensure uniformity of the powder. The powdered drug (100g) was subjected to extraction with 200 ml of carbon disulfide. The carbon disulfide extract of leave and stem of Mucuna prureins was subjected to sterilization using filtration process. (The analytical specifications of the extract are attached in sheet number: 1).
4. Detection of Alkaloid: The carbon disulfide extract was further extracted with water: chloroform mixture. The extract was made solvent free, treated with dilute hydrochloric acid and filtered. The filtrate was tested with alkaloidal reagents and it gave orange brown precipitate with Drangendroff’s reagent and cream precipitate with Mayer’s reagent.
5. Extraction of alkaloid: Moistened carbon disulfide extract was treated with alkali and free from the residues by treating with methyl alcohol and further deffated with petroleum ether. The, the drug was then extracted with ethyl acetate. This treatment freed the plant the pigments, sugars and other secondary constituents. The methyl alcoholic solution was evaporated to thick syrup and subjected to partition between aqueous acid solution and organic solvent. After continued extraction with solvent for some time, aqueous phase was made alkaline with ammonia. Basic aqueous solution was extracted with solvent followed by drying of alkaloid containing solution normally with sodium sulfate. Then filtration was carried out, which was further subjected to evaporation to yield the alkaloidal principle.
6. High performance liquid chromatography of alkaloid: HPLC was done to obtain finger print analysis of the alkaloid. The chromatographic studies resulted in a single peak at 257 nm confirming the presence of alkaloidal principle.
Alkaloids are known to exist in seeds of Mucuna pruriens. Tryptamine alkaloids like mucanine, mucananine and pruridine are reported to be present in Mucuna pruriens. However this is for the first time that presence of alkaloidal principles has been detected in leaves and stem of the plant. The further investigations in determination of the nature of alkaloids must be undertaken.
We are highly thankful to Dr. A.S.Sandhu, Scientist Department of Natural Products, National Institute of Pharmaceutical Education & Research (NIPER) and Dr. Satish Narula, Professor, Punjab Agriculture University, Ludhiana for their expertise in Botanical consultation.
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About the Researchers
Dr. Samir Malhotra, MD, DM (PGIMER, Chandigarh) Head, Medical Services, Ind-Swift Ltd
Dr Amrit Pal Singh, MD (Alternative Medicine), Medical Executive, Ind –Swift Lab, Chandigarh.
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