Macrocyclic Lactones (Macrolides) 



The macrolide (macrocyclic lactone) antibiotics are an in- 

 teresting new class of compounds elaborated by members of the 

 order actinomycetales and particularly by the genus strepto- 

 myces. The lactone moieties of these molecules resemble the 

 partially oxidized and alkylated aliphatic acids characteristic 

 of the related mycobacterium genus. A partial listing accord- 

 ing to Bergey's Manual of the members of the order actinomy- 

 cetales is shown below to clarify these relationships. 



Order. . . Acfinomycefales*^ 



Families. . . Actino- 



mycetaceae 



Strepto- 

 mycefaceae 



Myco- Actino- 



bacteriaceae planaceae 



Genera... Nocardia Sfreptomyces* Mycobacterium Actinoplanes 



Actinomyces* Micromonospora Mycococcus Streptosporan- 



Thermoactino- gium 

 myces 



A resemblance- to the steroid glycosides, for example strophan- 

 thin and oleandrin shown below, also has been noted. ^ 



OH 



Strophanthin 



* In the vernacular usage streptomycete-streptomyces and actino- 

 mycete may indicate either order or genus, perhaps more commonly 

 the order. 



1 R. B. Woodward, Festschr. Arthur Stoll, 524 (1957). 



