RAUWOLFIA - Alkaloids - Pharmacognosy and phytochemistry 2

Synonym: Rauwolfia root, Sarpagandha
 Biological source: It consists of the dried roots and rhizomes of Rauwolfia serpentina Benth.
 Family: Apocynaceae.

 The name Rauwolfia serpentina has been taken from the name of scientist Dr. Rauwolf and serpentina means snake like structured root.

 Geographical source: Several species of plant is distributed in the tropical region of Asia, America and Africa. It is commercially cultivated in India (mainly in Uttar Pradesh, Bihar, Orissa, Tamil Nadu, West Bengal, Karnataka, Maharashtra and Gujarat), Srilanka, Myanmar,
Thailand and America.

Cultivation and collection: Rauwolfia develops luxuriantly under wide range of climatic condition. It flourishes well in hot humid climate and grows quite well in shade. The clay loamy soil with handsome amount of humus is most recommended. Good drainage is
supposed to be ideal for its cultivation. 

Macroscopical characters
 Colour : Greyish yellow to brown (root bark) and pale yellow (wood).
 Odour : Odorless
 Taste : Bitter
 Size : 10-80cm in length and 1-3cm in diameter.
 Shape : Roots are sub-cylindrical, slightly tapered, tortuous.
 Fracture : Short and irregular.

Chemical constituents
 Rauwolfia contains 30 indole alkaloids. The total alkaloidal range is in 0.7-3 percent. Alkaloids are concentrated mostly in the base of the root and can be classified into:
1. Indole alkaloid
2. Indoline alkaloid
3. Indolenine alkaloid
4. Oxyindole alkaloid
5. Pseudo indoxyl alkaloid

 Reserpine is the main alkaloid in Rauwolfia. It also contains oleo resin, phytosterol, fatty acids, alcohols and sugars. The other alkaloids are Ajmaline, Ajmalicine, Rauwolfinine,
Rescinnamine, reserpinine, yohimbine, serpentine, serpentinine.

Chemical Test:
1. When fractured surface is treated with concentrated nitric acid, a red coloration observed.
2. When reserpine is treated with solution of vanillin in acetic acid, it shows violet red colouration.

Uses:
 It has antihypentensive activity. The most clinically important compounds are reserpine, rescinnamine and ajmalicine. Reserpine depletes the catecholamines stored at nerve endings and lowers the blood pressure. The drug is used in mild anxiety condition and neuropsychiatric disorders (due to its tranquillising effect). Deserpidine and Rescinnamine used as antihypertensive.
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