strychnine, aconitine & atrpine

1. Strychnos nux vomica
1. Strychnine (seeds)
2. Brucine (seeds, root, stems, leaves)
– Strychnine is over 10 times more potent than
brucine however it makes up only 1% of the ripe
seed of the Strychnine nux vomica.
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2. Strychnine
Morphology of Strychnos nux vomica
Molecular structure of strychnine
C21H22O2N
Common names- Kuchila, Kuchla
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3. Seeds of nux vomica
 Circular (sometimes flat/biconvex)
 2 cm in diameter & 0.5 cm in thickness
 Very tough testa with very fine, short silky fibres
 Odourless
 Bitter taste
– Fatal dose – 1-2 seed or 30-100 mg
– Fatal period – 30 minutes to 2 days maximum
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4. Signs & symptoms of strychnine
poisoning
• Intact seed doesn't cause any symptoms
• Crushed seed may cause signs & symptoms within 15-30
minutes-
– Anxious & restlessness (mainly due to increased CNS activity)
– Sensations become acute
– Respiration & circulation are slightly stimulated
– Blood stained froth, cyanosis
– Twitching & tremors of the muscles
– Colonic convulsions with gradual increase in contractions
– Severe convulsions may cause opisthotonous position & risus
sardonicus
• Death may occur due to respiratory/circulatory failure
during a prolonged convulsion
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5. Medicolegal aspects
• Poisoning is usually accidental either due
overdose or contamination by rat poison or by
accidental consumption (usually by children)
of seeds of nux vomica.
• Suicidal poisoning may occur due to rat poison
• Homicidal use is rare
• Used as abortificient
• Used as tribal arrow poison
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6. Extraction
• Strychnine & brucine are alkaloids and are extracted
with basic chloroform extraction technique.
• Brucine interferes with tests for strychnine so
separation of strychnine from brucine is mandatory.
– The chloroform extract is dried and 2 ml of H2SO4 is added
followed by 2 drops of HNO3.
– Allowed to stand for 30-60 minutes @ 10-200C.
– Then made alkaline with NaOH and extracted several times
with chloroform.
– This chloroform is washed & evaporated to dryness.
– The residue is now brucine free and tested for strychnine.
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7. Colour Tests
• Mandelin’s Test: for strychnine
– one drop of Mandelin’s reagent (1% solution of ammonium
vandate in conc H2SO4) is added to brucine free extract.
– Deep violet-blue or deep purple colour appears which
finally changes to yellow on long standing.
• Nitric Acid Test: for brucine
– To dried residue of extract is added one drop of conc HNO3.
– A blood red colour appears which changes to reddish
yellow and finally to pure yellow.
– Few drops of stannous chloride is added which causes
development of intense purple colour which is destroyed
by addition of few drops of conc HNO3
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8. Microcrystal Tests For Strychnine
Reagent Type/shape of crystal
Gold chloride Feathery rosettes
Potassium mercuric iodide Wedge shaped curved crystal or
Curved ferns
Mercuric chloride Nail shaped crystal
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9. TLC of Strychnos nux vomica
 Solvent systems:
1. Methanol : Ammonia :: 100 : 1.5
2. Cyclohexane : Chloroform : Diethylamine ::: 25 : 10 : 1
ACTIVE COMPONENT hRf in solvent sys 1 hRf in solvent sys 2
Strychnine 22 38
Brucine 28 18
Spray reagent:
•Dragendorff’s reagent (orange/red colour spots)
•Acidified potassium iodoplatinate (violet/blue or brown violet coloured
spot)
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10. UV & IR Spectrometry
• After purification by TLC the elution is made with
chloroform (2 ml) and is evaporated to dryness
– The residue is then dissolved in 2 ml of 0.1 N H2SO4
and studied in an UV spectrophotometer using 1 cm
cell from 220-320 nm wavelength:
– UV (λmax in nm):
aqu acid - 254
– Absorption curve is then compared with that of
control strychnine
• Principal peaks in IR spectrum:
– 1664, 764, 1050, 1110, 1282
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11. • Spray Reagent:
1. Dragendorff’s reagent – orange/red coloured
spots
2. Acidified potassium iodoplatinate – violet/blue
violet/ brown violet coloured spot
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12. GC of nux vomica
• Methanolic solution of purified extracted
residue is injected to GC column of 6’x4mm
(ID) with 2-3/100 SE-30 on chromosorb W,
@pressure 15 psi & temp 2220C..
Retention time for strychnine – 25.9
Retention time for brucine – 80.0
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13. Aconitum napellus
• Common Names:
– Aconite, Monk’s Hood, Wolfs bane, Blue Rocket, Mitha
Zahar, Dudhia Bish, Bikh, Mithabish
• Active component: Aconine (C34N49NO22)
1. Aconitine (acetyl benzoyl-aconine)
2. Picraconitine (benzoyl-aconine)
3. Bikhaconitine & indaconitine in traces
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14. Aconitum variegatum Aconitum napellus
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15. Poisonous Parts of Aconitum
• Part of plant which carries the active
components:
– Dried root is most poisonous part however all parts of
plant are poisonous.
• Identification of root:
– Conical in shape like monk’s hood
– Usual length is 2”-4” with base diameter of around 1”
– May be confused with horse-radish
– Causes tingling, numbness of tongue & lips when
tasted
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16. Sign & Symptoms
• Bitter sweet taste (hence ‘mithabish’)
• Causes tingling and numbness of oral cavity and limbs
• Constriction of throat
• Pain in abdomen with nausea and vomiting
• Paralysis of peripheral terminations
• Impaired hearing and vision
• Hippus reaction in pupils
• Circulatory collapse/respiration failure may leads to unconsciousness
followed by death
• Fatal dose:
– 1 gm of root or
– 25o mg of extract or
– 2-6 mg aconitine
• Fatal period:
– 45 minutes to 24 hours
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17. Post mortem Appearances
• Pallor of mucus membrane of mouth
• Congestion of brain, lungs, liver and kidneys
• Mucus membrane of stomach is inflamed
• Remains of root may be present if crushed
root was ingested
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18. Medicolegal Aspects
• Ideal homicidal (easily available, cheap,
certainity of death, no specific antidote,
decomposes quickly in body)
• Accidental poisoning by quackary medicinal
use
• Suicidal use is rare
• Used as tribal arrow poison
• Used in cattle poisoning
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19. Colour Tests
• Palet’s Test:
– To the acidified extract residue is added a few drops of
mixture of 25 gm syrupy phosphoric acid & 1 gm
sodium molybdate.
– The content is then heated over a small flame until
vapours appeared.
– A violet colour is obtained.
• Gold Chloride Test:
– (0.01N HCl + 5% AuCl2)
– Rectangular prism/ golden yellow needles
• Alvarez’s Reaction Test
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20. TLC of Aconitine
• Solvent system:
1. Methanol : Water :: 70 : 30
2. Cyclohexane : Chloroform : Diethylamine :::30:70:0.5
• HRf values for Aconitine are 20 & 65 for system1 &
system2 respectively
• Spray reagent:
 Dragendorff’s reagent (orange/red colour spots)
 Acidified potassium iodoplatinate (violet/blue or brown
violet coloured spot)
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21. UV and IR Spectrometry
• UV Spectrophotometry:
– After purification and elution from TLC plate the
elute is evaporated to dryness.
– The residue is taken into 2 ml of 0.1 N H2SO4 and
absorption spectrum is drawn with the help of a
UV spectrophotometer;
– λmax @234nm
• IR Spectrometry:
– Principle peaks for Aconitine KBr disk- 1092, 1273
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22. Dhatura fastuosa
• Dhatura plants are abundant in India.
• Dhatura stramonium is found in Himalayan regions
• Dhatura fastuosa is found in plains.
– Dhatura alba (white flowers)
– Dhatura niger (purple flowers)
• Poisonous Parts:
– All parts are poisonous
– Maximum concentration of active principles are found in
roots
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23. Morphology of Dhatura
• Fruit of Dhatura is commonly known as
“Thorn Apple” as it is a spherical shaped fruit
having multiple spikes (about a hundred) on
surface.
• Hundreds of seed are present in each fruit.
• Seeds are odourless, yellowish brown, kidney
shaped with two distinctive ridges on convex
surface.
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24. Active Principles
1. Hyoscine
2. Hyoscyamine
3. Atropine
• Fatal dose:
 Atropine – 50-60mg
 Hyoscine – 10 mg
 Seeds – more than 75 seeds are usually fatal for an adult while
40-50 seeds are enough to act as a stupefying dose
• Fatal period:
– Death occurs within 24 hours
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25. Mode of Action
• Both atropine & hyoscine block the
acetylcholine receptors and thus resulting in
sympathomimetic or parasympatholytic
actions.
• Atropine is also responsible for vagolytic
actions on heart and other vital organs
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26. Signs & Symptoms
• Bitter taste
• Dried mouth (xerostomia), difficulty in speech and
swallowing
• Skin is dry and hot. Face is flushed.
• Conjunctiva is congested, pupils are dilated, diplopia
• Pulse is rapid and voluminous
• Tachycardia, mania, convulsions, delirium,
hallucinations and hurried respiration
• Depressive phase follows the initial excitation phase.
– Deep sleep, coma and respiration depression may lead to
death
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27. Medicolegal Aspects
• Used as stupefying agent in highway robbery,
rapes and kidnappings
• Quackery abortions
• Adulterant in country liquor
• Occasionally used for suicides, rarely for
homicides
• Accidental poisoning in children
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28. Post-mortem Appearance
• Signs of asphyxia
• Congested organs
• Fragments of dhatura seeds in stomach
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29. Tests for Dhatura fastuosa
1. A drop of the stomach content extract, if applied in a rabbit’s
eye, there will be an instantaneous dilation of the pupils.
2. Microscopic Test:
– one drop of glycerine is added to the dried residue of extract.
– A characteristics structure similar to eyelids is seen.
3. Vitali’s Test:
– The residue of the extract is treated with fuming HNO3 and then
dried on water bath.
– After cooling, a few drops of freshly prepared caustic potash KOH
solution is added
– The colour turns to violet very soon and turns to red on standing
before finally disappearing.
– The reappears on addition of a few drops of alcoholic KOH.
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30. TLC of Dhatura fastuosa
• Solvent system:
1. Methanol (70) : water (30)
2. Cyclohexane (75) : chloroform (40) : Diethylamine (10)
• Spray reagent:
– Acidified iodoplatinate - violet/blue or brownish coloured
spots
Active component HRf system1 HRf system2
Atropine 33 31
Hyoscyamine 48 27
Hyoscine (scopolamine) 40 39
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31. UV & IR Data of Dhatura fastuosa
• UV Spectrophotometry:
• Principal peaks in IR (sample in KBr disc)
Active principle Medium λmax (nm)
Atropine Aqu acid 252, 258, 264
Hyoscine Aqu acid 251, 257, 263
Hyoscyamine Aqu acid 252, 258, 264
Atropine 1720, 1738, 1275, 1110, 712, 1037
Hyoscine 1730, 853, 1166, 736, 705, 1047
Hyoscyamine 1490, 1210, 1140, 810, 1020, 835
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