BIOS 111 Lecture Notes - Lecture 27: Cephalosporin, Amidase, Oxacillin
Document Summary
Penicillin g has a 4 membered ring stabilized by a 5 membered ring. Semi-synthetic penicillin: kept the ring system synthesized by fungus but added another half added b chemists. Destroyed by stomach so you needed an injection. Penicillinase is an enzyme that bacteria produce to inactivate penicillin. Semi-synthetics are acid resistant so they can be swallowed. Semi-synthetics have been made to be less allergenic. Semi-synthetics have been made to reach the cerebrospinal fluid. Beta-lactam ring needs to stay in tact for penicillin to be activated. Strong acid in stomach opens the bond. Methicillin has a blocky side group that protects the beta-lactam ring from being inactivated. You can"t take other antibiotics with penicillin because the penicillin won"t be effective. Clavulanic acid has a similar structure to penicillin. Combining penicillin with clavulanic acid acts as a penicillinase inhibitor. Penicillin amidase cleaves off an amino group so we can make semi-synthetic penicillin.
