Penicillin is a group of β-lactam antibiotics and was the first medication to be effective against bacterial infections caused by staphylococci and streptococci. Penicillin inhibits the formation of peptidoglycan cross-links in the bacterial cell wall through binding of the β-lactam ring of penicillin to the enzyme DD-transpeptidase. DD-transpeptidase cannot catalyze formation of these cross-links, leading to faulty cell wall production, degredation, and ultimately cell death. Many bacteria have developed resistance from extensive use.
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H2O: 100 mg/mL Soluble in methanol. Sparingly soluble in ethanol. Insoluble in chloroform.