Question

What are examples of beta lactam antibiotics?

Answer 1

There are three major classes of β-lactam antibiotics.

Explanation:

A lactam is a cyclic amide, and a β-lactam has the N atom attached to the β-carbon (C3) of the chain to form a 4-membered ring.

This is the characteristic feature of all β-lactam antibiotics.

β-Lactams are classified according to their core ring structures.

`color(brown)(bb"A. β-lactam rings fused to a saturated 5-membered ring")`

1. Penams: a thiazolidine ring fused to the β-lactam ring

Example: Penicillin G

`color(brown)(bb"B. β-lactam rings fused to unsaturated 5-membered rings")`

2. Penems: a dihydrothiazole ring fused to the β-lactam ring

Example: faropenem

3. Carbapenems: a dihydropyrrole ring fused to the β-lactam ring

Example: meropenem

`color(brown)(bb"C. β-lactam rings fused to unsaturated 6-membered rings")`

4. Cephems: a dihydrothiazine ring fused to the β-lactam ring

Example: cefalexin

5. Carbacephems : a tetrahydropyridine ring fused to the β-lactam ring

Example: loracarbef

6. Oxacephems : a dihydrooxazine ring fused to the β-lactam ring

Example: flomoxef