Question

Ergot alkaloids (e.g., Ergotamine) are biosynthetically derived from which precursor amino acid?

• A. Tyrosine
• B. Phenylalanine
• C. Tryptophan
• D. Ornithine

Hint:

Many alkaloids are built in the plant or fungus starting from a particular amino acid. If you know which amino acid gives which alkaloid family, these questions become easy.

Answer 1

The Correct Option is C

Concept:
Many alkaloids are built in the plant or fungus starting from a particular amino acid. If you know which amino acid gives which alkaloid family, these questions become easy.

Step 1:
Ergot alkaloids come from the fungus Claviceps and contain an indole ring in their structure. The indole ring is the giveaway, because the only common amino acid that carries an indole ring is tryptophan.

Step 2:
So tryptophan is the starting building block; it is converted step by step into the lysergic acid core that all ergot alkaloids (like ergotamine) share.

Step 3:
The distractors lead to other families: tyrosine and phenylalanine give isoquinoline alkaloids (like morphine), and ornithine gives tropane alkaloids (like atropine). None of these carry the indole ring.

Answer: Option (3) — Tryptophan.