Purine and pyrimidine analogs are building blocks of nucleic acids and are targeted by which class?

Purine and pyrimidine analogs are building blocks of nucleic acids and are targeted by which class?

• A. Alkylating agents
• B. Antimetabolites
• C. Platinum drugs
• D. Nitrosoureas

Answer: (B)

Nucleic acid building blocks are targeted by drugs that mimic purines and pyrimidines, disrupting DNA synthesis. These agents, called antimetabolites, work by resembling the normal nucleotides, competing with them in the pathways that synthesize or incorporate nucleotides, or by being incorporated into DNA/RNA and causing faulty replication. This mechanism specifically hinges on nucleotide mimicry, making antimetabolites the class that targets purine and pyrimidine analogs. Other drug types listed affect DNA in different ways—by alkylating or crosslinking—rather than by imitating nucleotides—so they don’t fit this mechanism.

Nucleic acid building blocks are targeted by drugs that mimic purines and pyrimidines, disrupting DNA synthesis. These agents, called antimetabolites, work by resembling the normal nucleotides, competing with them in the pathways that synthesize or incorporate nucleotides, or by being incorporated into DNA/RNA and causing faulty replication. This mechanism specifically hinges on nucleotide mimicry, making antimetabolites the class that targets purine and pyrimidine analogs. Other drug types listed affect DNA in different ways—by alkylating or crosslinking—rather than by imitating nucleotides—so they don’t fit this mechanism.