AMINOGLYCOSIDE ANTIBIOTICS. IV

In a previous paper1) we reported that Bacillus circulans, strain No. YQW-B6, produced a complex of aminoglycoside antibiotics designated Bu-1709, of which the two major components, A1 and A2, were identified as butirosins A and B2). Two additional components, E1 and E2, have now been isolated and characterized. They have antibacterial spectra similar to the butirosins but with substantially less intrinsic activity. Bu-1709 E1 and E2 contain the paromamine moiety in place of the neamine moiety of the butirosins.