Page "Antibacterial" Paragraph 2

The term antibiotic was first used in 1942 by Selman Waksman and his collaborators in journal articles to describe any substance produced by a microorganism that is antagonistic to the growth of other microorganisms in high dilution.

This definition excluded substances that kill bacteria, but are not produced by microorganisms ( such as gastric juices and hydrogen peroxide ).

It also excluded synthetic antibacterial compounds such as the sulfonamides.

Many antibacterial compounds are relatively small molecules with a molecular weight of less than 2000 atomic mass units.