123 



Polyene Macrolides 



Various other substances, e.g. the etamycin, valinomycin and 

 actinomycin types of antibiotics, could be classed as macrolides 

 since they all contain large rings in which lactone groups par- 

 ticipate. 



a. POLYENE MACROLIDES 



225 Flavofungin, C^„H4s09 Dihydrate. 



A polyene macrolide containing 7 acetylatable hydroxyl 

 groups, 5 hydrogenatable carbon-carbon double bonds of 

 which at least 4 are conjugated, contains no alicyclic ring, 

 has at least 2 and probably 3 C — CH^. Ozonolysis indi- 

 cates a CH;^(C,jHii) group. The most important struc- 

 tural elements are: 



— CH=C- 



<=CH- 



CH3 CH3 



-(CH=CH)3— C=0, CH3(C6H„) 

 O 



CloHi3(OH)7 



Shown to be distinct from pimaricin, nystatin, amphoteri- 

 cin-B, fungichromin, lagosin, filipin and fumagillin. 



A streptomycete 



R. Bognar, Angew. Chem. 72 139 (1960). 



226 Pimaricin ( Myprozine ) , C34H49O14N, colorless crystals, m.p. 

 200° (dec), U.V. 279, 290, 303, 318 m^ in methanol. 

 Proposed structure: 



CH2OH 



I 

 OH O O CHOH 



Streptomyces natalensis n. sp. 



A. P. Struyk, I. Hoette, G. Drost, J. M. Waisvisz, T. Van Eek 

 and J. C. Hoogerheide, "Antibiotics Annual 1957-1958," Med- 

 ical Encyclopedia, Inc., New York, p. 878. 



James B. Patrick, Richard P. Williams and John S. Webb, 

 J. Am. Chem. Soc. 80 6689 (1958). (Structure) 



