Name an alkaloid which is used for the treatment (i) hypertension (ii) malaria fever and (iii) pain

Explanation

### Step-by-Step Solution:

1. **Identify the alkaloid used for hypertension:**
- The alkaloid used for the treatment of hypertension (high blood pressure) is **Reserpine**. It is derived from the plant *Rauwolfia serpentina* and is known for its antihypertensive properties.

2. **Identify the alkaloid used for malaria fever:**
- The alkaloid used for the treatment of malaria fever is **Quinine**. Quinine is extracted from the bark of the cinchona tree and is effective against the malaria-causing parasite *Plasmodium*.

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