- Any of a class of organic compounds containing a large lactone ring made up of twelve or more members.
- Any of a class of antibiotics having a macrolide ring structure linked to one or more sugars. Macrolides are produced by actinomycete bacteria of the genus Streptomyces and act by inhibiting protein synthesis. Erythromycin is a macrolide.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.