Structure of the classical<unk> s The<unk> s (sg. ) are a class of β-lactam antibiotics originally derived from the fungus Acremonium, which was previously known as "Cephalosporium". Together with<unk> amycins, they constitute a subgroup of β-lactam antibiotics called<unk> ems.<unk> s were discovered in 1945, and first sold in 1964.
Cephalosporin
Sulfonamide 
Extended-spectrum penicillin
Quinolone antibiotic
Tetracycline
Minocycline
Anthopleurin
Penicillin