Editing Erythromycin (section)

=== Composition ===

Standard-grade erythromycin is primarily composed of four related compounds known as erythromycins A, B, C, and D. Each of these compounds can be present in varying amounts and can differ by lot. Erythromycin A has been found to have the most antibacterial activity, followed by erythromycin B. Erythromycins C and D are about half as active as erythromycin A.<ref name = "www.toku-e.com"/><ref name="pmid4091529">{{cite journal | vauthors = Kibwage IO, Hoogmartens J, Roets E, Vanderhaeghe H, Verbist L, Dubost M, Pascal C, Petitjean P, Levol G | title = Antibacterial activities of erythromycins A, B, C, and D and some of their derivatives | journal = Antimicrobial Agents and Chemotherapy | volume = 28 | issue = 5 | pages = 630–3 | date = November 1985 | pmid = 4091529 | pmc = 176346 | doi = 10.1128/aac.28.5.630 }}</ref> Some of these related compounds have been purified and can be studied and researched individually.