Penicillin : A Class Of Drugs

1255 WordsDec 2, 20156 Pages
Content Antibiotics Introduction Discovery Structure Mechanism of action Class of drug Medical use Adverse effect Antibiotics:  Antibiotics is the chemical substances which derived from living organisms that are capable to inhibit or kill the other living organism’s life process.  The first antibiotics were isolated from microorganisms but some are now obtained from higher plants and animals.  Over 3,000 antibiotics have been identified but only a few dozen are used in medicine.  Antibiotics are the most widely prescribed class of drugs comprising 12% of the prescriptions in the United States.  A common scheme of classifications for antibiotics is drawn below: Introduction of penicillin:  Penicillin are a class of beta-lactam antibiotics.  Penicillin was the first antibiotic discovered from the mold Penicillium notatum in 1928 by Alexander Fleming at St. Mary’s Hospital in London, England.  The structure of penicillin is a nucleus consisting of a beta-lactam ring (4 membered cyclic amide) and a side chain. The beta-lactam ring is necessary for antibacterial activity, and the side chain determines the antibacterial spectrum and pharmacologic properties.  Beta-lactamases (also called penicillinases) are enzymes that deactivate penicillin by destroying the beta-lactam ring by hydrolysis. Beta-lactamases allow bacteria to be resistant to penicillin.  Various penicillin differ mainly by the structure of the side chain.  In addition to their
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