Page 28 - Pharmacognosy-I (02-06-06-102)

Overdosage:

Symptoms of poisoning can occur after ingestion of one bean. Strychnine
doses of as little as 1.5 mg (30-50 mg of the drug) initially cause restlessness,
feelings of anxiety, heightening of sense perception, enhanced reflexes,
equilibrium disorders, and painful stiffness of the neck and back
musculature. Later, twitching, tonic spasms of the masseter and neck
musculature, and finally painful convulsions of the entire body that are
triggered by visual or tactile stimulation occur. Dyspnea comes following
spasm of the breathing musculature. Death occurs through suffocation or
exhaustion. The lethal dosage for an adult is approximately 50 mg strychnine
(1-2 gm of the drug). Chronic intake of sub-convulsive dosages can also lead
to death under similar conditions after a period of weeks. This is due to an
accumulation of drug in the body, particularly in those who
have liver damage.
Note: Strychnine is used as rodenticide

Tests for Identity:

1. General Test for Alkaloids: Extract the powder with dilute HCl, filter, to
the filtrate add few drops of Mayer's reagent, a yellowish white precipitate is
obtained.
2. Test for Strychnine: Strychnine gives violet colour with ammonium
vanadate in H2SO4 (Mandelin's Reagent).
3. Test for Brucine: Brucine develops a crimson or red colour with nitric
acid.

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