Rauwolfia
Source, diagnostic characters, constituents,
tests and uses
Objectives
At the
end of this lecture, student will be able to
• Discuss
the source, diagnostic characters, constituents, tests and uses of Rauwolfia
Rauwolfia
Synonym
• Indian snake root, Chootachand, Sarpaganda
Biological Source
• Dried rhizomes and roots of Rauwolfia serpentina contains
not less than 0.15 % of reserpine group
of alkaloids, calculated as reserpine
Family
• Apocynaceae
Rauwolfia – Macroscopy
• Size
• Shape
• Colour
• Fracture
• Odour
• Taste
Microscopy
• Periderm
1. Cork – Stratified
– Smaller, suberized,
unlignified
– Larger, suberized,
lignified
2. Phellogen
3. Phelloderm
• Secondary
phloem
• Secondary xylem
• Medullary rays
–
Xylem region are lignified
– Phloem region are not lignified
• Starch and twin
prisms of calcium oxalate
Powder characters
Organoleptic characters: Taste, Colour, odour, taste
Active Constituents:
• Alkaloids – Indole alkaloids – Nearly 30 (1.5-3%) – root
bark
• Phytosterols, fatty acids, unsaturated alcohols, sugars
(dextrose, sucrose)
• Indole alkaloids –
Weakly basic indole group
• Reserpine group- Reserpine, Rescinnamine, desperidine
Tertiary indole alkaloids
• Ajmaline group- Ajmaline, ajmalicine
• Serpentine group- Serpentine, serpentinine, alstonine
Chemical tests:
• Freshly fractured surface with Conc. Nitric acid- red
colour in medullary ray
• Vanillin in acetic acid – Violet colour – Reserpine
• Powder + Sulphuric acid in p-dimethyl amino benzaldehyde –
violet to red colour (Indole alkaloids)
• Tincture of drug in UV light – blue fluorescence
Uses:
• Treatment of hypertension (Antihypertensive) and in
certain neuropsychiatric disorders (Hysteria)
• Treatment of insomnia and certain forms of insanity
• Sedative and transquillizing agent (Reserpine group)
• Ajmaline – pharmacological properties similar to quinidine
– cardiac arrhythmias
• Yohimbine – treatment of impotence
Substitutes
• R. vomitoria – African rauwolfia – bushy
plant/tree, contains bands of sclereids and large vessels
• R. densiflora – absence of stratified cork,
sclerenchyma (cortex and phloem)
• R.tetraphylla – Uniform cork (non-stratified), abundant
sclereids, absence of recinnamine
Summary
• Dried roots of Rauwolfia serpentina with bark
intact, contains not less than 0.15 % of reserpine group of alkaloids,
calculated as reserpine Indole alkaloids – Reserpine – antihypertensive, sedative