Question

Which one of the following alkaloid contains isoquinoline nucleus?

• A. Quinine
• B. Hyoscyamine
• C. Piperine
• D. Papaverine

Answer 1

The Correct Option is D

To answer this question, we need to identify which of the given alkaloids contains an isoquinoline nucleus. An isoquinoline nucleus is a bicyclic structure derived from quinoline, where the nitrogen atom is in the second ring, characteristic of many alkaloids.

1. Quinine: Quinine is an alkaloid derived from the bark of the cinchona tree. It contains a quinoline group and is known for its anti-malarial properties. It does not have an isoquinoline nucleus.
2. Hyoscyamine: Hyoscyamine is a tropane alkaloid found in plants like belladonna and other members of the Solanaceae family. It has a tropane ring structure and does not possess the isoquinoline nucleus.
3. Piperine: Piperine is an alkaloid that gives black pepper its spicy taste. It contains a piperidine and piperic acid structure, lacking an isoquinoline nucleus.
4. Papaverine: Papaverine is an opium alkaloid that acts as a vasodilator. It is characterized by an isoquinoline nucleus in its structure, distinguishing it among the options provided.

Among the given options, Papaverine is the only alkaloid that contains an isoquinoline nucleus. Therefore, the correct answer is Papaverine.