Peptide antibiotics and chelation — Which option correctly lists peptide antibiotics known to form chelates with metal ions as part of their antimicrobial action or uptake?

Introduction / Context:Some peptide antibiotics interact with metal ions. Chelation can underlie DNA strand scission (as with bleomycins) or drive uptake via iron-transport pathways (as with sideromycins), making chelation mechanistically relevant.

Given Data / Assumptions:

• Bleomycins are glycopeptide-like antitumor/antimicrobial agents that bind metal ions (e.g., Fe) and, with oxygen, induce DNA damage.
• Sideromycins are antibiotics conjugated to siderophores, chelating Fe and hijacking iron uptake systems.
• Vancomycin is a glycopeptide inhibiting cell wall synthesis; chelation is not central to its activity.

Concept / Approach:Identify antibiotics whose function involves metal ion binding or siderophore-mediated chelation. Both bleomycins and sideromycins qualify, while vancomycin does not.

Step-by-Step Solution:

Verification / Alternative check:Chemistry references depict Fe-bleomycin complexes generating reactive species; sideromycin examples (e.g., albomycin) use Fe-chelation for uptake.

Why Other Options Are Wrong:

• Bleomycins only: incomplete; sideromycins also chelate.
• Sideromycins only: incomplete; bleomycins also chelate.
• Vancomycin: does not rely on metal chelation.

Common Pitfalls:Equating “glycopeptide” with chelation; most glycopeptides do not act through metal binding.

Final Answer:Both (a) and (b)