Antipseudomonal penicillins

Penicillin - Synthesis and Drug Profile

Antipseudomonal penicillins

i. Carbenicillin

Synthesis

Properties and uses: It is a white to off white crystalline powder with bitter taste, hygroscopic in nature, soluble in water or alcohol, insoluble in chloroform or ether. It differs from ampicillin by having an ionizable carboxyl group substituted on the alpha carbon atom of the benzyl side chain rather than an amino group. The carboxyl group is thought to provide improved penetration of the molecule through the cell wall barriers of gram-negative bacilli as compared with other penicillins. A similar sequence starting with 3-thiophenylmalonic acid leads to the ticarcillin. It is acid labile being a malonic acid derivative, it decarboxylates readily to penicillin G. It is effective in the treatment of systemic and urinary tract infections. It has low toxicity, except allergic sensitivity, and the drug interferes with platelet function resulting in bleeding.