Macrolides are a group of antibiotics isolated from actinomycetes that share three common chemical characteristics: a large lactone ring, a ketone group, and a glycosidically linked amino sugar. Some examples mentioned are erythromycin, clarithromycin, and azithromycin. Macrolides work by binding to the 50S ribosomal subunit and inhibiting polypeptide chain elongation and protein synthesis. They are used to treat infections like streptococcal pharyngitis, tonsillitis, respiratory infections, diphtheria, and tetanus. Erythromycin is soluble in alcohol and organic solvents but only slightly soluble in water. Clarithromycin is a semis