B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) Pharmaceutical Chemistry 4

Question 1

Which reaction is used industrially to synthesize aspirin from salicylic acid?

Accepted Answer

Acetylation with acetic anhydride

Answer

Aspirin is synthesized by acetylating the phenolic -OH of salicylic acid with acetic anhydride under acidic catalysis.

Question 2

What does a high partition coefficient (logP) value indicate about a drug molecule?

Accepted Answer

High lipophilicity and good membrane permeability

Answer

A high logP indicates the drug preferentially partitions into the lipid phase, indicating greater lipophilicity and enhanced membrane penetration.

Question 3

Which pharmacophore feature is essential for β-lactam antibiotics to inhibit bacterial cell wall synthesis?

Accepted Answer

The strained four-membered β-lactam ring

Answer

The strained β-lactam ring acylates the active-site serine of transpeptidase enzymes, irreversibly inhibiting bacterial cell wall cross-linking.

Question 4

In the context of pharmaceutical chemistry, what is meant by bioisosterism?

Accepted Answer

Substituting one atom or group with another of similar size and electronic properties to maintain biological activity

Answer

Bioisosterism involves substituting atoms or groups with similar steric and electronic properties to optimize pharmacokinetics while retaining pharmacological activity.

Question 5

What is the primary degradation pathway of penicillins in aqueous solution?

Accepted Answer

Hydrolysis of the β-lactam ring

Answer

The strained β-lactam ring is highly susceptible to hydrolysis in aqueous conditions, especially under acidic or basic pH, leading to loss of antibacterial activity.

B.Pharm. Bachelor of Pharmacy Practice Test

B.Pharm. Bachelor of Pharmacy Practice Test

B.Pharm. Bachelor of Pharmacy Bachelor of Pharmacy (B.Pharm.) Pharmaceutical Chemistry 4