Page "Antibacterial" Paragraph 3

With advances in medicinal chemistry, most of today's antibacterials chemically are semisynthetic modifications of various natural compounds.

These include, for example, the beta-lactam antibacterials, which include the penicillins ( produced by fungi in the genus Penicillium ), the cephalosporins, and the carbapenems.

Compounds that are still isolated from living organisms are the aminoglycosides, whereas other antibacterials — for example, the sulfonamides, the quinolones, and the oxazolidinones — are produced solely by chemical synthesis.

In accordance with this, many antibacterial compounds are classified on the basis of chemical / biosynthetic origin into natural, semisynthetic, and synthetic.

Another classification system is based on biological activity ; in this classification, antibacterials are divided into two broad groups according to their biological effect on microorganisms: bactericidal agents kill bacteria, and bacteriostatic agents slow down or stall bacterial growth.