Poisoning of the CNS Flashcards
True Alkaloids - Groups
1) Tropane Alkaloids
2) Isoquinoline Alkaloids
3) Piperidine Alkaloids
Terpenoids - Groups
1) Diterpene derivatives
2) Triterpenoid derivatives (steroidal compounds)
3) Triterpenoid derivatives (non-steroidal compounds)
Thiaminase Enzymes in Plants
1) Cleave thiamine (Vitamin B1) molecule
2) Renders them Biologically Inactive
3) Vitamin B1 is essential for many animals (and humans), as they are unable to biosynthesise it
4) Vitamin B1 has a key role in carbohydrate and fatty acid metabolism
Symptoms and Plants of Thiaminase Enzymes
Weakness, decreased production, milk with bluish colour
Enlarged heart, low heart rate
- Field Horsetail
Characteristics of Tropane Alkaloids
1) A tropane ring
2) Solanaceae
3) 2 types - Solanaceous alkaloids + Coca alkaloids
Tropane alkaloids: Mechanism of Action
1) Site of action: smooth and cardiac muscle, gland cells, peripheral ganglia and CNS
2) Solanaceous alkaloids = anticholinergics = reducing the activity of the parasympathetic nervous system and promoting sympathetic predominance
3) Symptoms = 30-60 mins
4) Alkaloids = excreted with urine
Symptoms of Tropane Alkaloids
1) Dry Mouth
2) Dilated Pupils
3) High Heart Rate
4) Rapid Breathing
5) Spasms, seizures, death
Plants with Tropane Alkaloids
1) Henbane
2) Jimson Weed
3) Deadly Nightshade
Characteristics of Isoquinoline Alkaloids
1) Papaveraceae
2) NB derivatives = morphine, codeine, papaverine, and rhoeadine
Opioids: Mechanism of Action
1) Opioids bound to the opioid receptors of neurons
2) Close Ca2+ channels and inhibit Ca2+ ions to enter the neurone
3) Open K+ channels = K+ ion efflux
4) Hyperpolariztion occurs = lees likely to fire
5) Suppression of transmission of pain signals
Opioids Symptoms
1) Pinpoint pupils
2) Spasms in the stomach and intestinal tract, vomiting
3) Slow and heavy breathing
4) Hallucinations, coma, death
Opioid Plants
1) Field Poppy
2) Opium Poppy
Characteristics of Piperidine Akaloids
1) Apiaceae
2) Piperidine Ring biosynthesised from Lysine Amino Acid
3) Most NB derivatives are Coniine, Coniceine, and Lobeline
Coniine: Mechanism of Action
1) Blocks the Nicotinic Cholinergic Receptors in the Neuromuscular Junctions - Paralysis
Coniine Symptoms
1) Trembling, movement disorders
2) Uncontrolled Urination
3) Heart rate: first slow, later high
4) Respiration rate becomes low, respiration laboured, and irregular
Coniine Plants
Hemlock
Terpenoids - Diterpene Derivatives Characteristics
1) Ranunculaceae, Asteraceae
2) Major compounds are Aconitine and Taxus alkaloids
Aconitine: Mechanism of Action
1) Makes the Voltage-Gated Na+ ion channels permanently open
2) High Na+ levels in muscle cells inhibits Na+/Ca2+ exchangers
3) Cell membrane cannot be repolarized - paralysis
Aconitine Symptoms
1) Sensation of burning
2) Tingling and numbness in the mouth
3) Vomiting
4) Motor weakness; slowing movements
5) Heart and respiration failures - cardiac arrest, death
Aconitine Plants
Wolfbane
Triterpenoid Derivatives (steroidal compounds)
1) Liliaceae and Solanaceae
2) Steroidal skeleton bounds to N- heterocyclic rings
Solanum Alkaloids: Mechanism of Action
1) Acetylcholinesterase enzyme is inhibited by Solanine
2) Na+ channels stay open
3) No new Action Potential
4) No more muscle contractions
5) Paralysis
Solanum Alkaloids
Black Nightshade
Triterpenoid Derivatives (non-steroidal compounds)
1) Glycosides forming an amphipathic molecule (a saponin)
2) Pentacyclic molecules
3) Non Taxon- Specific Compounds
Plants
Corncockle
