The antibiotic elaiomycin (1) is a naturally occurring azoxy compound isolated from the fermentation broth of Streptomyces gelaticus.1 Elaiomycin exhibits novel biological activity since it inhibits axenic multiplication of Mycobacterium. The antibiotic has also been found to induce tumors in rats.3 As a naturally occurring azoxy compound, elaiomycin is a member of a small class of unusual natural products that includes (p-carboxyphenyl)azoxy cyanide,4 the cycad toxins macrozamin and cycasin,5 and the antifungal agent LL-BH872m.6 Previous experiments in our laboratory have demonstrated7 that C-5 to C-12 of elaiomycin and the B-nitrogen atom of the antibiotic are derived from n-octylamine. We now report experiments which establish that the (methoxyamino)butanol moiety of the antibiotic is biosynthesized in an unusual manner.