Q.50 Name the fungus whose extract from the sclerotia can be used to produce a
powerfull hallucinogenic drug?
1. Agaricus
2. Claviceps purpurea
3. Alternaria solani
4. Neurospora crassa
Claviceps purpurea, known as ergot fungus, produces sclerotia rich in ergot alkaloids that serve as precursors to powerful hallucinogens like LSD. NEET Q.50 tests fungal pharmacognosy, linking sclerotia extracts to psychoactive drugs from rye parasites. Option 2 identifies this infamous fungus.
Correct Answer
The fungus is 2. Claviceps purpurea. Its purple sclerotia on rye contain lysergic acid derivatives; extracts yield ergotamine, basis for LSD synthesis, causing hallucinations via serotonin receptor agonism.
Option Explanations
Options contrast medicinal/edible fungi with pathogens and genetic models.
| Option | Fungus | Key Trait | Relevance to Hallucinogen |
|---|---|---|---|
| 1. Agaricus | Edible mushroom (button) | Culinary use | No sclerotia or alkaloids; safe food fungus. |
| 2. Claviceps purpurea | Ergot pathogen | Sclerotia → ergot alkaloids (LSD precursor) | Hallucinogenic via neurotoxic effects. |
| 3. Alternaria solani | Tomato blight pathogen | Leaf spot disease | Produces toxins but not hallucinogens. |
| 4. Neurospora crassa | Bread mold model | Genetic studies (Beadle/Tatum) | Lab tool; no psychoactive sclerotia. |
Only Claviceps matches sclerotia-based hallucinogen production, historically causing ergotism outbreaks.
Ergot Alkaloid Mechanism
Sclerotia extracts drove medieval “St. Anthony’s Fire” with visions and convulsions.
Claviceps purpurea Details
Parasitizes grasses; sclerotia replace grains, yielding lysergic acid diethylamide precursors affecting 5-HT2A receptors for profound hallucinations.
This question highlights fungal secondary metabolites in microbiology and toxicology for NEET aspirants.
