Question

Which of the following peptides will act as antibiotics?
A. Gramicidin
B. Ergothioneine
C. Actinomycin
D. Chloramphenicol
E. Acetazolamide
Choose the most appropriate answer from the option given below:

• A. A, E
• B. C, D, E
• C. A, C, D
• D. B, C, D

Hint:

Peptide Natural Antibiotics: Gramicidins, Actinomycins, Polymyxins, Bacitracin, Chloramphenicol.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Non-ribosomal peptide and polypeptide antibiotics disrupt bacterial membrane permeability, transcription, or translation.

Step 2: Detailed Explanation:
Evaluating the antibiotic compounds:
1. A. Gramicidin: A linear non-ribosomal polypeptide antibiotic (mixture of gramicidins A, B, C) that forms cation-conducting channels across bacterial membranes.
2. C. Actinomycin (Actinomycin D): A chromopeptide polypeptide antibiotic containing cyclic pentapeptides that intercalates into DNA and blocks transcription.
3. D. Chloramphenicol: A broad-spectrum bacteriostatic antibiotic targeting the bacterial 50S ribosomal peptidyl transferase.
4. (Ergothioneine is an antioxidant; Acetazolamide is a carbonic anhydrase inhibitor).
Thus, A, C, and D act as antibiotics.

Step 3: Final Answer:
Therefore, the antibiotics are A, C, D, matching option (C).