Question

Cephalosporin nucleus consists of \ldots

• A. Beta-lactam ring + Thiazolidine ring
• B. Beta-lactam ring + Oxazolidine ring
• C. Beta-lactam ring + Dihydrothiazine ring
• D. Beta-lactam ring + Pyrrole ring

Hint:

Cephalosporins are often used as an alternative to penicillins in patients with mild penicillin allergies, though cross-reactivity can occur.

Answer 1

The Correct Option is C

The cephalosporin nucleus is a core structure of cephalosporin antibiotics, which consists of a $\beta$-lactam ring fused to a six-membered dihydrothiazine ring. The $\beta$-lactam ring is responsible for the antibacterial activity by inhibiting cell wall synthesis, while the dihydrothiazine ring distinguishes cephalosporins from penicillins (which have a thiazolidine ring). The other options, such as oxazolidine or pyrrole rings, are not part of the cephalosporin structure.
Thus, the correct answer is Beta-lactam ring + Dihydrothiazine ring.