Which of these secondary metabolites is an alkaloid ?

Options

A. Codeine
B. Anthocyanin
C. Abrin
D. Curcumin

Answer

To determine which of the given secondary metabolites is an alkaloid, we can analyze each option provided:

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 have important ecological functions, such as defense mechanisms or interactions with other organisms.

2. **Identifying Alkaloids**:
- Alkaloids are a class of nitrogen-containing compounds that are typically derived from plant sources. They often have significant pharmacological effects and can be toxic in certain doses. Common examples include morphine, caffeine, and nicotine.

3. **Analyzing the Options**:
- **A. Codeine**: Codeine is a well-known alkaloid derived from the opium poppy. It is used primarily as a pain reliever and cough suppressant.
- **B. Anthocyanin**: Anthocyanins are pigments responsible for the red, purple, and blue colors in many fruits and flowers. They are not alkaloids.
- **C. Abrin**: Abrin is a toxic protein found in the seeds of the rosary pea plant. It is not classified as an alkaloid.
- **D. Curcumin**: Curcumin is a compound found in turmeric and is known for its anti-inflammatory properties. It is not an alkaloid.

4. **Conclusion**:
- Based on the analysis, the only compound listed that is classified as an alkaloid is **A. Codeine**.

### Final Answer:
The secondary metabolite that is an alkaloid is **A. Codeine**.