Which of the following secondary metabolites Is a drug?

Options

A. Abrin
B. Ricin
C. Carotenoids
D. Vinblastin

Answer

To determine which secondary metabolite is a drug, we need to analyze the options provided and understand the characteristics of secondary metabolites.

### Step-by-Step Solution:

1. **Understanding Secondary Metabolites**:
- Secondary metabolites are organic compounds that are not directly involved in the normal growth, development, or reproduction of an organism. They often play roles in defense mechanisms, competition, and signaling.

2. **Analyzing the Options**:
- **Option A: Abrin**:
- Abrin is a toxic protein derived from the seeds of the Abrus precatorius plant. It is known for its poisonous properties and is not used as a drug.
- **Option B: Carotenoids**:
- Carotenoids are pigments found in plants that are responsible for yellow, orange, and red colors. They are important for photosynthesis and provide health benefits but are not classified as drugs.
- **Option C: Vinblastine**:
- Vinblastine is an alkaloid derived from the Madagascar periwinkle (Catharanthus roseus). It is used in chemotherapy to treat various types of cancer, making it a recognized drug.
- **Option D: Ricin**:
- Ricin is another toxic protein derived from castor beans. Like abrin, it is a poison and not used as a drug.

3. **Conclusion**:
- Among the options analyzed, **Vinblastine** is the only secondary metabolite that is used as a drug, specifically in cancer treatment.

### Final Answer:
The secondary metabolite that is a drug is **Vinblastine**.