Alkaloids
✓ Source, diagnostic characters, constituents, tests and uses of
➢ Rauwolfia
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Objectives
• At the end of this lecture, student will be able to
✓ Discuss the source, diagnostic characters, constituents, tests and
uses of
➢ Rauwolfia
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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
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Rauwolfia – Macroscopy
❖ Size
❖ Shape
❖ Colour
❖ Fracture
❖ Odour
❖ Taste
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Rauwolfia – 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
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Rauwolfia – Powder characters
Organoleptic characters: Taste, Colour, odour, taste
Parenchyma Xylem vessels
Stratified cork (lignified, pitted
Xylem parenchyma)
Calcium oxalate
Prism
Starch grains
Rauwolfia
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 wgrwowu.Dpu-loSMeirxp.ceomntine, serpentinin7e, alstonine
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Rauwolfia
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
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Rauwolfia
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
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Rauwolfia
• 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
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Summary
Rauwolfia
✓ 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
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Thank you
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