56 



NATURE. FORMATION. AND ACTIVITIES 



is replaced by a C7Hi:i():{ fragment of un- 

 known striu'ture. 



Oleandomycin is similar to erythromycin 

 in that it contains desosamine, but its neu- 

 tral sugar is oleandrose, which is closely 

 related to cladinose. The structure of this 

 antibiotic has recently been elucidated by 

 Hochstein (1960). 



CH.,() 



OH— ,' 



CH.,-i 



CH, 



CH.,0 



-OH 



OH— r 



CHs- 1 



J— OH 



■()" 



O 



cation and characterization of these anti- 

 biotics. 



Methymycin and picromycin do not con- 

 tain a neutral sugar. They both have the 

 same lactone ring, to which desosamine is 

 attached. They differ only in the point of 

 attachment of desosamine to the lactone 

 ring. Methymycin has the following struc- 

 ture, the star indicating the point of attach- 

 ment of desosamine in the picromycin mole- 

 cule : 



CH3 CH3 



Carhomycin contains a large lactone ring 

 which is not fully saturated and which fea- 

 tures an epoxide function adjacent to the 

 unsaturated carbonyl function. Attached to 

 this ring is the amino sugar mycaminose, to 

 which is attached the neutral sugar my- 

 carose : 



OH CHa 



CHs CH3 



ororHoC'HfC'H,)^ 



CH, 



CH, 



Table 18 lists some properties of tetra- Neomethymycin differs from merhymycin 



phenylboron derivatives of some macrolides. only in the position of a hydroxyl group. 

 These derivatives can be used in the purifi- The exact structure of the spiramycins 



T.^BLE 18 



Tetraphetiylborou derivatives of antibiotics (Zief et al., 1957) 



