Classification of cephalosporins  

Beta-lactams are a class of antibiotics that contain a beta-lactam ring (which is a highly active 3-carbon and 1-nitrogen ring). This class includes:^3a

• Penicillins - include natural penicillins, beta-lactamase resistant agents, aminopenicillins, carboxypenicillins and ureidopenicillins. They all contain a nucleus of 6-aminopenicillanic acid ring and other ringside chains.^3a
• Cephalosporins - contain a 7-aminocephalosporanic acid nucleus and side-chain containing 3,6-dihydro-2 H-1,3-thiazine rings.^3a
• Carbapenems - a carbapenem coupled to a beta-lactam ring that confers protection against most...