[Structure of the chromophore fragment of copsomycin]

The chromophore moiety of the copsomycin molecule was isolated in the form of dimethyl ether as an individual substance from the products of antibiotic acid hydrolysis. Physicochemical properties of the chromophore were studied. UV, 1H and 13C NMR, mass spectrometry and elementary analysis showed that the copsomycin molecule moiety was identical to the chromophore moiety of the molecule of multiomycin or nosiheptide.