Antibiotic obtained from lichens is

Options

A. Neomycin
B. Usnic acid
C. Polymixin
D. Viridin

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the antibiotic that is obtained from lichens. We have four options to consider: neomycin, arsenic acid, polymyxin, and viridin.

2. **Identifying the Source of Each Antibiotic**:
- **Viridin**: This antibiotic is produced by a soil fungus known as Trichoderma viridi. Therefore, it is not derived from lichens.
- **Polymyxin**: This antibiotic is derived from the bacterium Bacillus polymyxa. This indicates that it is of bacterial origin, not from lichens.
- **Arsenic Acid**: This is a natural occurring dibenzofuran derivative found in several lichen species. This suggests a connection to lichens.
- **Neomycin**: This antibiotic is derived from Streptomyces fradii, which is a type of soil bacterium. Hence, it is not obtained from lichens.

3. **Conclusion**: Based on the information gathered, arsenic acid is the antibiotic that is obtained from lichens.

4. **Final Answer**: The antibiotic obtained from lichens is **arsenic acid**.

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