Metabolic products of microorganisms. 196 The structure of ethericin B, a new diphenylether antibiotic

Ethericin B(Ia) was isolated together with ethericin A1) from fermentations of Aspergillus funiculosus Tü 680. The structure of ethericin B was established as 4-carbethoxy-5,5'-dihydro-xy-3,3'-dimethyl-diphenyl ether by chemical degradation, mass spectrometry, 1H-NMR and comparison with synthetic 4-carbethoxy-5,5'-dimethoxy-3,3'-dimethyl-diphenyl ether.